Web Analytics RiceHigh's Pentax Blog: January 2009

Saturday, January 31, 2009

Problematic DPR "Reviews" (Esp. Recent Ones)

As I have always said, camera gear "review", by its name, is just a kind of unprofessional assessment on camera gear, which is more or less consisted of many personal opinions and comments made by individual writer rather than more on scientific measurements. For professional ones with proper measurements, which should strictly follow those well-established International Standards and/or Industrial Standards such as ISO, IEC EN, ANSI, ASTM and etc., for the testing procedures and then for the verifications of the obtained results, they are called "Lab Tests" or "Bench Tests", NOT "Reviews".

But then about ten years ago, there came the DPReview (DPR) website, which the site owner Phil Askey used to call his user reports on digital cameras and gear as "reviews". Those reports of him were just summaries of his personal findings (based on some very simple "measurements" or even not), comments and opinions about the gear: no more, no less. Since at that time, there was not much useful information on the Internet and ditto for many of those printed magazines, in which most of the "test" reports are almost useless, the DPR became more and more popular and "large". A good example for those limited information age of the Internet is no better to quote the Steve's Digicams which produced really crappy useless "reviews" (you'd better download an official user manual from an official site and could get more info about the cameras!) could still earn a living! Nowadays, the term "review" has now been widely accepted and has a generalised meaning for any gear test or comment report, regardless of how they were done, i.e., anyone can write a "review", from a novice who knows almost nothing versus a real expert who has been working in the industry for years and has acquired different professional qualifications in the relevant fields and areas of the industry.

So, let me go back to the topic. What makes me to write this blog article immediately is that I can see the quality, usefulness and creditability of those published camera reviews by the DPR are declining. But yet I know that the general public of the Internet *still* trust too much the DPR (well, it is just a tradition by now). The general audience, whom are huge for those who read their site, just rely too heavily on their reports. For all these reasons, I opt to write here something to share my observations and thoughts with a sole intention to draw the attention of any of those internet readers for the flaws and problems of those DPR reviews (more so recently, and also the upcoming reviews, very likely). In fact, I can see that DPR and Phil Askey have spent no more new effort in improving the quality and standard of their reviews with better contents. Instead, Phil's crew and staff who called themselves as "technical writers", are just knowing to follow strictly the old report template that has been used by their boss for long, which IMO is just rather outdated by today's standards.

Now, let's go on to see why the DPR reviews are now so problematic. I will elaborate more in details with *some* examples:-

1. Inconsistent Judgements/Yardsticks

Since Uncle Phil sold his DPR site to Amazon and became the Overlord of the site, he employed a team of crew of his own so that Phil could have more time to enjoy more of his life from his hard earned money, which should not be a small sum as Amazon is just a very large company! Well, just think if you had the money, you would want more time, so that you could spend your money! Right? :-)

But after that, all the DPR reviews were written by different person(s), sometimes one, sometimes two, sometimes three and sometimes four. Phil sometimes participated with his name appeared as one of the reviewers, but not often. But then what's the (real) problem? With different combinations of different persons as the reviewers, their viewpoints, judgements or simply prejudgements could be very different, even though it seems that there is a well-established "system, which is just more or less a document template for the review report format.

Nevertheless, on the other hand, I don't know whether Boss Phil would give any "input", actually I mean a "pointer" or a finger to his staff for what direction they should write for each of the DPR reviews, for his own "impressions" on different cameras for particular brands and models, or just his "intentions". But what I can see is that serious inconsistency in judgements and there exists many subjectivities, which overweighs much of the more important facts and thus harms their objectiveness much. When they made their marks and conclusions, I can see many biases, which are rather illogical, with very different "yardsticks" when different cameras are "reviewed" - it can be easily noticeable that they have more tolerances with "large" brands.

Say for example in their K-m review published today, they write in the "Conclusion" that the in-camera jpeg image quality is really rather bad for the K-m and a 6.5 mark out of 10 was given. But in their side-by-side comparison to the Oly E-420, for anyone who can read with a more careful mind, it actually shows there is NOT MUCH difference in the image quality (which they have also mentioned themselves) and that they even say the highlight and shadow transition and preservation are better for the K-m. But then the most ridiculous thing is that they still gave a 8.0 mark for the image quality for the E-420 in their E-420 review.

Whilst I do agree with their preliminary findings that the K-m in-camera jpeg is not on a par with the Canon 1000D (which is true from looking at their posted pictures), and also not as good as the RAW converted jpeg of K-m itself, the quality differences between the K-m against the E-420 and Sony A200 is not of that big differences (with 420's jpegs are close in resolution and A200's slightly better). So, why they did not find serious problems with the Sony and Olympus, even though the Canon is undoubtedly is better, for the evidence they showed.

Hence, they just have very different tailor-made yardsticks for doing different reviews, I must say. IF they compared DSLR to DSLR, all of them should be considered and compared on the same basis, NO MATTER they are Full Frame, APS-C or 4/3. They SHOULD NOT have much more "tolerances" just because the 420 is a 4/3 camera! Silly and stupid enough? (Or maybe the true reason is just about the "brand" behind?)

Whilst they say one of the biggest Cons of the K-m is that "Default JPEGs too contrasty and poorly sharpened" (the first Con they list, which led to the poor marginally "Recommended" rating for the K-m). But then the writers also know well and have mentioned that it is the "default" tone/colour curve as in different regions in the world (actually when the user selects a different language, a different colour/tone profile will be set by the camera). However, since this sharpening level and steep tone curve profile is just a "picture profile" which is just a matter of taste, what "Con" is it actually? How "Big" is that "Con"? What's the fuss about??

2. Incomplete Views by Deemphasizing Shortcomings (of the gear they "like"), Overemphasizing Shortcomings (for gear they "don't like")

Of course, none of we average Internet readers would know the reasons behind for why they actually "like" or "dislike" individual camera of a particular brand and model. But I can see many facts, for example:-

In their very recent Panasonic G1 review (the last review prior to the K-m one), they highly praised the camera and have given the camera very high ratings/overall rating. In fact, I myself have been very interested in the G1 too and I appreciated much the innovativeness and creativity of Panasonic too. Since I have been finding a compact and lightweight DSLR to replace my K100D, I just went to try it. But shortly after I tried it for several minutes, I told myself this camera was not the one I would buy (The set price tag is okay for me). Why? The G1 is a pseudo DSLR with an Electronic ViewFinder (EVF), but that EVF, despite it is quite strong in Spec on paper and is also expensive to make, it is just something not much useful if it is compared to any *optical* viewfinder: Its dynamic range is rather limited - I could not even see those well lit parts of the Pana showroom against those just somehow darker areas at the same time in that environment or vice versa. Pixelisation of the finder image was obvious (owing to the large magnification, which the DPR praise). Flickering of EVF image was obvious. Colour reproduction was fake. So, why STILL the DPR could give the G1 a "Pro" about the EVF of the G1 and praised loudly about its EVF?? If they are mind correct (I mean technically, not commercially) in their methodology, all "DSLRs" under their tests should be considered on the same basis - they should not just because it is the best EVF then they gave it a high mark and even emphasizing it it a "great" "Pro"(!?). The fact is that the EVF of the G1 is *still* far worse than any optical viewfinder, even the worse ones, e.g., those in the 4/3 entry level models - Physics. Owing to the serious biases of the DPR writers, their reviews could be very misleading.

And, as for the K-m review, another major reason they told the world for giving such a rarely seen and low rating (by now and in recent years) and why they are so disliked about the camera is yet unsubstantiated (putting aside the inferior in-camera jpeg (but yet they do not mention about the best retained colours and details by the K-m at higher ISO speeds), which is: The missing selected AF point indication (the illuminated red-points).

It should be noted that the K-m has only five AF points which are put very closely to the frame centre (which is still more than a few of those "Highly Recommended" current entry level DSLRs by other brands). In the following, I would talk more about that red indication from the viewpoint of a Photographer and then more from an Engineer.

First, from the user point of view, practically:-

A. For stationary objects: If the user want to have total control on the selection of focus point (and for knowing where the focus will fall on), he/she just has chosen the (Single) Central AF point already and do re-composition for each frame when taking the pictures. On the other hand, if the user, whom is usually a beginner or novice, let the camera decide and choose the AF point *automatically* for him/her, WHY the user cares about which point? Why it is needed? Will they care? Of course, if there is such an indication, it is mostly welcomed. But I don't think it is a serious flaw, never; and

B. For moving objects: Actually, under most circumstances, it is more important to know which focus point(s) the camera has chosen, since practically it is not feasible to re-compose and time usually does not allow. Indeed, I want the indication for my Canon 5D too. I did write at the DPR long time ago when I first got my 5D for asking Canon to implement it, at least as an option. But waaait, do Uncle and Boss Phil knows *even* the Canon 1 series truly professional DSLRs, namely, IDS and 1D MkIII, will have the red AF illuminations disabled in the Continuous / Servo AF mode (Yes, I am sure that they know!). So, what's the point, then?? And, why didn't DPR give the Canon flagships low marks and then "not recommending" the EOS 1D and IDS bodies because of this reason??? In fact, they have never done that, and never dared not and will never dare to do so (and of course!). All Nikon DSLRs have the indication even in Servo AF mode (as I have said, at least as an option - IIRC), so why not DPR trashed the Canons?

Now, from the technical point of view, the entry level Canons, say, the 1000D AF point indication is just a small and weakly illuminated red point which is hardly visible, especially when shooting outdoor, which just means that it is not much better. Since the 1000D has a particularly small viewfinder vision, such indication is yet not as useful as it would be, theoretically. In contrast, the K-m does have the largest viewfinder image magnification amongst all entry level DSLRs, which is undoubtedly larger than that of the 1000D and D60, so why didn't Uncle Phil's guys emphasize this so strongly?? (There is only one brief and vague statement mentioned in the whole review)

All in all, should the above two most "important" and "killing" shortcomings really worth for so many marks to be deducted. With such weak reasons and "grounds" to finally draw up a "Recommended (with Reservation)" rating, I am totally not convinced. It just looks like some simple excuses were to be found and it's time for DPR to show their "objectiveness", since they have just given too many and so many "Highly Recommended" ratings in recent years. And, as you can see the numerous responses on the Net already, conspiracy theory will come in again for the true reasons behind..

On the other hand, I wish to point out that the K-m does not have the LiveView function (technically fully explained here), why the DPR don't even mention this as a "Con", which is a more valid point IMO. Would it be just because the *Nikon* D60 also doesn't have that? In their D60 review, this is even not listed as one of the Cons, neither. Really very good "consistency! Well done, DPR! They were most brilliant and clear enough to mention that discrepancy in the words of the Conclusion, which are well hidden, together with some kinds of defense. In fact, for what I know about those new DSLR beginners, especially whom used to shoot with P&S or Prosumer DCs but no DSLR reflex experience before, LiveView is just a feature on the top of their requirement lists when they are to make their choice (whether the LiveView will be useful to them or not when they have their DSLRs is yet another problem).

P.S. I have all those entry level Canon and Nikon DSLRs at work and I myself own and use so many Pentax DSLRs and also a high-end Canon Full Frame DSLR. As such, I believe I actually know very well for all those practical differences, between different models by different makers.

3. Unqualified Incompetent Persons; Not Observing International/Industrial Standards; Infringement to the Intellectual Property of the ISO

- DPR measure resolution values by human eyes, with no consideration of the MTF % or simply ignore it completely! Note: MTF - Modulation Transfer Function, fully explained here (by Norman Koren), here (by Bob Atkins), here (by Michael Reichmann) and here (by Ken Rockwell). Well, DPR don't know about MTF??

- DPR do not test exposure accuracy based on Standards, not even they recorded and shown any histogram before they commented on the "exposure accuracy" of the DSLRs (Funny). But then you can download all their stuff, inspect the EXIF data, view the histograms and compare, if you have the time!

- DPR do not test AF timings before they made so many "Conclusions". Oh, yes, they concluded by *Opinions* and *Impression*, I almost forget.

- DPR do not test AF accuracy! No object/chart was tested/posted but they dared to comment! So, what's the difference of those "technical writers" from an Average Joe who writes at any user commenting websites like the Epinions. All these, including those made by the DPR, are just individual *user comments* afterall, which are based on nothing!

- DPR do not test system time lags of the DSLRs, which is just a key manufacturer's performance spec which is usually not published, as opposed to what Japanese CIPA and Imaging Resource measures.

- DPR (and actually Phil) even dared to steal and modify the ISO test chart (which Phil bought long ago) for measuring resolution and then marked a "copyrighted" by the DPR!? He is just so much conceited but was not even aware that it is illegal! Didn't Uncle Phil know that the ISO test chart was and is still copyrighted by the ISO and is the Intellectual Property owned by the ISO, not the DPR! (and of course not by Phil Askey personally - he was just one of the customers of the ISO publications!)

- DPR technical writers and editor (i.e., Phil Askey) have no professional qualification of any kind shown and told by them as related to the industry and field. Phil only told us that he was an IT man.

- And so on.. (but I would stop here, you *think* and *judge* yourself!)

Well, besides all the above facts and "Cons" of the DPR (Now I have almost completely "reviewed" them! Haha), there are more to note for the global Internet atmosphere and trend:-

1. Decreasing Reference Values

Last but not least, with the rise of Web 2.0 and interactive information and data sharing platforms, there are more and more useful materials shared on the Net daily such as Blogs (from different persons) and those end-users posted sample photos, which could be very valuable if the readers can select carefully and most importantly, those information could be more *honest* and "faithful". Other than the DPR, we now have much many choices at places like Blogger, Flickr, YouTube, or even Facebook and more. If you like, you can still pixel peeping on those un-retouched original images (till the end of the world!) which are not intentionally selected and picked. So, what are the true values of those primly commercial websites run by *merchants* with incompetent employees nowadays??

2. Conflicts of Interests

I think quite many people have already forgotten that DPR and so many alike sites are just running solely commercially, despite that they seem to be providing "free" (really?) services to the *end-users*? But what are their sources of incomes?? How come they could and can earn a living? And, when and under what situations they will be unable to survive and need to close down?? (And then they need to find a job after losing their *businesses*! ;-) Are they afraid?)

Go find the simple answers yourself!

Conclusion and My Humble Final Reminders

DO NOT take personal opinions solely and heavily relied just on *one* single source, no matter how authoritive the source looks or you think to be. Do more researches by reading more other articles and read more honest user opinions as well. Only by doing that, you can gather more facts, INSTEAD of subjective opinions and comments (including those by so-called self-claimed "technical writers" or "reviewers" who earn money for a living from all those associated commercial deals and Ads.

But on the other hand, do totally BEWARE of those brand-blinded fanboys and their opinions, which must be filtered out! When you see persons who always do not allow anyone to say anything "negative" on *any* shortcomings of "their" gear (they particularly are very sensitive to the "brand" they ""own"") and/or just that "their" gear are *always* "perfect, you should IGNORE THEM totally! And of course, whilst I believe that I am totally honest enough, please also don't take my words solely neither, do read my this disclaimer for why, just in case if you have not yet!

Most importantly, do try out your interested camera gear *yourself* hands-on before you act. Otherwise, you will have remorse!

With this trend of declining quality reviews for what DPR give us, I bet that the site will be going on a down slope in the long future once the internet community recognises that it is no more a reliable and valuable resource. Actually some more better sites which are carrying gear tests in a professional manner are coming up recently, like the DxOMark.com (and my report of its birth here), with a very good web interface too. So if you really intend to measur(e)bate and pixel-peep, do read better sites instead of those sub-standard ones! For old sites, I would rather recommend the "friend" site of DPR, the Imaging Resource, at least their camera reviews are based on the Imatest for some of their tests, which is using the ISO standards, e.g., for the exposure and colour accuracy tests, and they did select more sensible camera performance parameters to measure than the DPR.

The Earth is rotating, years ago, the type of DPR reviews and standard report format might be still good enough to satisfy the needs of the Internet audience and readers, owing to the limited information and little competition on the Net, as I have said in the beginning. Nowadays, in 2009, with the more advanced Web 2.0 and open platforms for all Internet users, I think the one-way information sharing is just outdated. In fact, I have seen no real improvement of the DPR website (their web design is dated - when you use different machines to view their pages and you will know what I am talking about) and more importantly their tests and the way they made their tests are dated also.

Lastly, I would remind here anyone to think twice and twice again if he/she is still really to make purchasing decision solely based on the DPR "reviews". My final humble advice: Take the DPR reviews nowadays as grains of salt. If you read, read their RAW materials presented *first*, which are readily downloadable from their site. Judge the materials they put but not the words from their mouths, never. They just give misleading and partial conclusions, owing to many many reasons.

Friday, January 30, 2009

Strange K20D Noise Patterns

Various K20D users at the PentaxForums have reported that they experienced strange pattern noises which appear in particular regions of a frame and are particularly noticeable at ISO speeds higher than ISO 1600:-


All the user reports in the above thread are self-explanatory, with sample pictures posted and the issues found are clearly described.

But yet a particular user who has a very careful mind found that "the K20D has a strange vertical bar at the left side of the image, visible (normally) only by extreme pushing the contrast and brightness" here, in his this reply post.

He further states that, "So far I was able to produce it with every K20D I saw."

Actually, this "vertical bar" can also be seen at ISO 100 at which the situation is the "best", see another follow-up post from the same poster. A histogram for shooting a dark frame is posted.

The strangest thing here is that the unevenly distributed pattern noises are appearing in particular regions, and particularly existent in the Blue channel. They appear at image corners, left side or at the top and bottom of the frame. They appear not only at high ISO speeds but also at lowest ISO 100. It is only that the noises are much more obvious at high ISO speeds whereas at low speeds, they are well hidden but push processing or any kinds of more "extreme" post processing will reveal all these.

So, the culprit? It should be an immature sensor and associated hardware (and may also be the associated software) used in the K20D, which are to be debugged!

Indeed, I hope Samsung will do their debug jobs quicker and faster so that it makes it possible for Pentax to roll out their K20D replacement model soonest (as it should be). If not, Pentax should really source and get another sensor unit to put it into the K20D replacement, IMHO. In fact, the K20D is essentially a dead model now, for what the limited number of sales and low popularity/availability as seen. There are less and less shops carry the K20D and it can be hardly found. And even for rare places where the K20D can be found, they are just sitting there for collecting dust despite the K20D are now selling for very little money (very close to the 450D kit price).

Read Also:-

K20D has VPN under Cold Temperature?

K20D Banding Problem Reported at Low ISO Speed

Wednesday, January 28, 2009

My Second Tests on the K-m and Observations

Further to my first trial on the K-m previously, I tried the K-m recently for three more times, with a DAL 18-55 kit, my (crippled) 43 Limited and FA 24-90 on the body respectively, separately for 3 different K-m demo units at different places. Here are something interesting or special to share:-

1. AF is overall fast and smooth. Even for my FA 43, which has been renowned as one of the most slow (and noisy) focusing lens for its AF (mechanism). Hunting was non-existent and minimal when it came near the final focus point, especially when the lens was at f/2.8 or wider. Since that 43 Limited lens has a particularly long run for its AF range, and it's also noisy, I could feel well and note more clearly about the speed control of the whole AF process, by the K-m's "new" AF system. I found that the control was more precise and speed changes were smoother - the best I have seen for a Pentax DSLR ever! Now, the K-m feels more like my Canon (5D), although the AF motor speed is slower, as long as a fast AF lens is used.

2. Exposures were found to be very accurate under white light environment, whilst under yellow light, it still underexposed a bit, unfortunately.

3. Since both of my above Pentax lenses used had the aperture coupler removed, I could easily checked about the exposure accuracy and consistency of the K-m's stop-down metering. I tried with my 43 Limited with apertures set from f/2.8 to f/11 at each f-stop. To my really BIG surprise, the results were *dead* accurate, for the first time for a Pentax DSLR (which I have used all, for all major models!). My experiences were that my *ist D/DS and K100D used to underexpose more (and much) when stopped down (more) and the K10D/K20D did overexpose (more and much) when stopped down (further). So, this must the greatest improvement I have ever seen for a Pentax DSLR as long as exposure accuracy is concerned!

4. Viewfinder is yet bright and easy to see until f/5.6. But since its magnification is not high, the DoF could not be easily seen, though. Anyway, it would be fairer to mention that the finder's view is yet noticeable larger than that of the D60 and the EOS 1000D and of course far better than the super tunnel view of the 4/3 E-520.

5. Build quality is very good and I found it to be the best if it has to be compared against other entry level DSLRs like the D60, 1000D, E-520 etc. I found the K-m felt more solid than my K100D which I have owned for long. The RTF (built-in flash) can be closed very tightly without any play for one of the demo units (whereas the other two are okay). So, if you have the luck, you can get a perfect one.

6. Size is the smallest amongst the above competing entry level models mentioned (and actually I compared them size by size for all of them). The K-m is even smaller than the 4/3 E-520, although not lighter. The DAL 18-55 kit lens is smaller (and lighter?) than the Canon and Nikon ones. The Oly standard kit is smallest and lightest but the Pentax's is an APS-C lens anyway instead of the smaller 4/3 format anyway.

7. Weight is *acceptable* with NiMH AA rechargeables. With AA Lithums, it feels less heavy.

8. Last but not least, I found that overall the K-m's ergonomics are good to excellent. The body's grip is very good to hold despite the small size of the K-m, better than my "small size" Pentax DSLRs like the *ist DS, D and K100D. The overall balance of the body felt very well as the heavy AA rechargeables in the grip yet contributes to stability at the right ;-). And, contrary to some K-m users reported, I found no problem in operating the column of standard four DSLR buttons which are now re-located at the right side, and can now be operated easily by the thumb, which I found it to be even a good thing just in one hand, with the right hand only. :-)

9. Finally, FIMW mentioning, the external colour LCD display, which is the only LCD display in the camera now (since there is now no top monochrome status LCD panel), will be turned on when the shutter release button is *first* half-pressed. When the shutter release button is half-pressed again, the external LCD will be turned off. If the user has already looked through the viewfinder, it will do the AF and AE as usual and turn off the external LCD at the same time as it may be a nuisance when the eye is looking at the finder, especially in dark environment. In fact, I carried out the above operations smoothly and naturally without any problem and I think Pentax's engineers have done a good job with a thoughtful design.

Overall, I am quite pleased with the K-m after my second series of trials with it. I particularly feel excited for the improved exposure accuracies, particularly for the 1st time reliability for stop-down metering which has not been seen for a Pentax DSLR before! (needed to be verified more fully - I cannot guarantee here 100% unless I have owned the camera!).

All in all, I would say the K-m is a very good DSLR, which I can see Pentax should have paid a lot of efforts in debugging their line of (somehow problematic, frankly) DSLRs, despite that they have made it very late, I think still "Late is better than None"! Still, I would give Pentax a "Well Done!" comment here, at my Blog! (which is not easy and should be very "valuable"! ;-D)

As my last remarks, for anyone who is considering the K-m (including me of course :-)), I would still like to remind that there are still two (might be important things, depending on usage) are omitted and missing in the K-m, namely: 1. There is no cable switch socket; 2. There is not an SR on/off switch/lever - The SR on/off is now to be selected via the camera's menu. And, as usual, the SR is recommended to be turned off when the camera is mounted on a tripod or when the user is doing pan shots.

Saturday, January 24, 2009

Compatibility List of Some Pentax Full Frame Lenses on Canon 5D Body

As I promised last time, below are the full details:-

(Do read my last article for the technical bases if you're going to try any "surgery" on your lens(es)! And, do it at your own risk!!)

Lens Model
Reason of Incompatibility (If Not Compatible)
Technical Remarks
Comments about the Image Quality on 5D
F 17-28/3.5-4.5 Fisheye
Mechanically it is compatible but the built-in lens hood would cause vignetting near 17mm as the K-to-EOS adaptor makes the lens rotated when installed.
Excellent and Perfect, as it used to be on my film Pentax SLRs!
FAJ 18-35/4-5.6 AL
No but Still Yes
No aperture ring!
Maybe I shall still try to modify it just as an always wide opened ultra wide lens. It maybe possible to fix the aperture at wide opened position (or any aperture position) just with a screw, just like I did with my DA 18-55 and tested it before.

Edit 4-19: Succeeded! See Full Story Here.
Good to Very Nice. Samples Here.
FA 24-90/3.5-4.5 AL
Original pedal-type lens hood will cause vignetting at the wide side, owing to the rotated lens when mounted.

So far my experiences with this lens on 5D is quite good, accurate colours, somehow nice bokeh and if stopped down a bit, resolution is good from corner to corner and vignetting will become less obvious. It is interesting to note that this lens performs much better on the 5D than on any of my APS-C cropped Pentax DSLRs - even the bokeh is different and the bokeh on 5D is nicer, real surprise!

Might do a head-to-head comparison later on to see how this compact Pentax 24mm standard zoom could compare against my much more expensive Canon EF 24-105L which was almost 3 times for the prices I paid.
FA 28/2.8 AL
The rear lens element is protruding out too much and has conflict with 5D's large mirror when it moves. (I found it out simply by attaching a piece of Kodak lens cleaning paper (in two folds) and fixed it close to the glass as possible, so as to protect the rear glass surface before I pressed the shutter release button to try)
F 35-70/3.5-4.5No
1. The little barrel for the rear glass element protruding out too much;

2. The protection ring with plastic protruding protector for the aperture coupler is linked to the aperture control mechanism and is in one piece => Destructive modification is required, even if not because of the first reason.
I am really sorry about the failure as the Pentax F 35-70 is the best very first standard kit zoom ever made on Earth! And actually I have already removed the protruding part of the plastic protector to try - the position is just so critical so that I was not sure if it could work if not tried - not possible just by observation :-(

FA* 43/1.9 Limited
F 80-200/4.7-5.6
Very good for a super lightweight Tele-zoom of this spec. Stopping down to f/8 will yield very sharp images.
FA* 85/1.4
-1. Requires dissembling of mount and proper techniques and great care are required!

(My Hints: Work under bright illumination, put on the workbench a large piece of white paper, put it flat as the workspace, and get proper screw drivers and forceps. More importantly, always face the lens with mount-side upwards during the surgery!)

2. Screws for mount and aperture coupler are thread-locked with special glue. Much force is required to get the screw unfixed (and with great care at the same time so as to not damage the screws and any slippage of the screw driver which might even scratch the glass!).
Perfect, as long as the focus is correct! (mostly correct with the focus indication by 5D)

This lens is just Wonderful on the 5D! Excellent lens will always be excellent!

DFA 100/2.8 Macro
1. Requires dissembling of mount;

2. The aperture controlling/coupling mechanism would get off its position after the mount is removed. It's needed to be put back into proper position before resemble back the mount.

1. This lens' colour rendition on 5D is far better, accurate and consistent than on my *ist DS and K100D. I just wonder if this is related to the more intelligent and more accurate Auto White Balance of the 5D than those Pentax DSLRs. Anyway, a big surprise and a real bonus to me.

2. The resolution is very high at the centre but even at f/8, very extreme corners are having some kinds of blur when shooting infinity objects. My FA*85 just blows it away just at f/4, with corner to corner sharpness with very high resolution.

New Samples Here! (Macros)
F* 300/4.5
Probably, but have not yet succeeded
This luxury top-of-the-line 80s Pentax AF lens is so sturdy to dissemble! I could not even turn any of the screws which fix the mount! I suspect these are thread locked by special type of strong thermal glue. As I do not have a heater screw driver with (precise) temperature control at my home, I gave up! If I had one, I would try starting from the lowest temperature first :-( )
The mount is needed to be dissembled first. I guess if I could remove the mount, this lens should be compatible! :-(

Tamron 1.4 MC4 Teleconvertor
Dissembling of rear mount is required.
Acceptable performance, degrade the F*300/4.5 image quality somehow but still an usable combo.
Sigma 28/2.8 KPR
No but I still can use it, see the right!
This cheaply designed lens actually cannot be dissembled and removed by parts for the aperture coupler without destroying it - very maintenance unfriendly! So, I just do it by blending it fully downwards to avoid any conflict. At least, I still did not cut it!
Acceptable colours, high resolution at the centre but at (not even very extreme) corners the 5D outclasses this Sigma prime, stopping down way down to f/11 only shows little improvement, and at near wide opened, the blurs are just so obvious.

During the course of dismantling the aperture coupler, I found that there is a trick to adjust the exposure tendency of all those Pentax lenses by fine tuning the aperture coupler' exact position, in a precise way. This is valid from any F to the latest DFA lenses. For example, my FA 28/2.8 AL did tend to overexpose by about 1/3 EV on my K camera and now it exposes just as accurate as my FA Limited or the FA*! So, that aperture coupler can be the evil which just introduces more exposure errors, as long as exposure accuracy (which is of prime importance indeed) is concerned.

I am now being very happy for using my good to excellent Pentax lenses on my 5D as each of which is of some kind of unique characters and quality. Of course, I am still hoping that there will be a Pentax Full Frame DSLR body to come, although it is not likely in the foreseeable (near?) future :-(( If the day really comes, all my those somehow modern (but yet all discontinued, including my FA 43 which is of the better old version) Pentax AF lenses, will have their full automatic functions re-activated again, instead of now they are just "manual" lenses on my 5D! :-( And, to some: don't tell me to put my those excellent Pentax Full Frame lenses on any of the current Pentax DSLR bodies, the produced results and image quality is no way as good, or just not even come close! Believe it or not!

Read Also:- K-Mount Metering and Exposure Bases - A Technical Brief

Friday, January 23, 2009

When the Focusing Screen Lies - Part 2

Last time I talked about how focusing screens of DSLRs could lie, in giving incorrect focus (and DoF as well, of course) as viewed through the finder and giving incorrect metering values, especially when stop(ped)-down metering is done.

As for Pentax DSLRs, actually I have never seen any of them could accurately meter the light when the Pentax lens mounted is stopped down, i.e., metered at a non-"A" lens aperture position. The *ist D, DS and K100 used to underexpose when stopped down whilst the K10D and K20D do overexpose.

Until a few months ago, I made my Cantax K5D 135 Full Frame DSLR with a Pentax K-mount. After I had used it more and more with my Pentax glass, I discovered that my 5D's focusing screen gave incorrect metering values as well, for stop-down metering. Similar to the K10D and K20D, it overexposes pictures at smaller apertures. The more the user stops down, the more overexposure will result.

The worst thing is: Since all my Pentax AF lenses are now just used as legacy "manual" lenses on my 5D, I rely more on the viewfinder (and actually the focusing screen) in doing the MF manually than ever before I used my Pentax AFSLRs/DSLRs. Unfortunately, the 5D's standard focusing screen, which is called the Ee-A (Eg-A* for 5D MkII), does also lie (much) in telling the correct focus. It is just made with a large DoF than real afterall, although the finder is intentionally made very bright with this standard screen. *To side track a bit, the 5D MkII needs a different "Eg" series because the viewfinder's coverage is larger at 98% now, so the screen size is different, and probably not because of any characteristic difference between the two series, I suppose.

Well, in order to achieve correct metering and exposure results, I needed to calibrate the exposure for that standard screen, against when an EOS prime is mounted and set in the Av mode, so as to find out the exposure discrepancy levels and characteristics, at different f-stops used. I had also checked that if the Time values measured by the camera obeyed the Law of Reciprocity with different Aperture values selected, mechanically at the "manual" lens or electronically for an EOS lens. Since different lenses have different light transmission efficiency (or light loss, in the other way), I had to also check the histogram for the exposure results. In short, my EOS lenses are in general accurate but not so for my Pentax "manual" lenses when they are mounted on the 5D. But in general my Pentax lenses all have better light transmission efficiency than my Canons. My generalised calibration results are as follows:

Table 1: Exposure Errors of Canon 5D Standard Focusing Screen Ee-A (Eg-A for 5D MkII)
Aperture * :
Exposure Error :
(+ve means over,
-ve means under)
Corresponding EV
Compensation Required :
(or 0EV)
Not Required

*Remark: Values Not Absolute, different lenses have different light transmitting efficiency and could affect the "centre" f-number.
The above table shows the results of my Pentax FA*43/1.9 Limited on 5D.

As you can see from the above, the exposure errors are roughly linear, which is a fortunate thing out of an orginally unfortunate anyway. Beside, the brightness level of the environment does not affect very much of the above characteristics, which is yet another lucky thing. However, the exposure errors are large in magnitude which cause much inconvenience when using my Pentax lenses. Another good thing I found with my Pentax lenses (FA Limited and FA* in particular) is that the mechanical aperture values are fairly to highly accurate and I must say Pentax had done an excellent job in manufacturing and calibrating those Pentax F/FA lenses with such a mechanical aperture ring, especially for their high grade FA Limited and FA* lenses which are almost dead accurate. I guess this also explains why the Pentax MZ-S was designed to use aperture ring to select the f-number in Av mode, instead of using the "A" setting, even there is one on all Pentax film AF lenses. I bet the old Pentax knew about this technical tricks very well and only mechanical aperture on lens is used, more accurate exposure is possible.

Now, let's look back at the focusing issue. Although my K-mount EOS adaptor does have a PCB and chipset on mount for confirmation the focus by the AF system electro-optically, I would rather prefer I could do turn the lens' MF ring faster if aided by a more effective and accurate focusing screen, before the focus is to be confirmed by the PCB and chipset finally. However, the problem of the Ee-A screen is that Canon intentionally made it too bright and they had assumed the users are using AF most of the time (well, that's case anyway if only EOS or AF lenses are used) and the viewfinder image is only for the purpose of picture framing. To explain the Physics, the trick is that Canon fine tuned the laser-carved microlenses on the screen to make them to gather more light onto the "focal plane" (at the focusing screen, not the real one on the sensor) and thus even for those slightly out of focus light beams are gathered. As a result, whilst the composite projected image on the screen is very bright but the out-of-focus regions are in focus now(!), which is the true drawback.

Unlike Pentax, Canon do have more options for their DSLR users. They have special made another focusing screen called the "Super Precision" Focusing Screen, the Ee-S (Eg-S for 5D MkII). With this screen, exposure is in general very accurate and no exposure *inconsistency* of any kind was found, except that there was a consistent -1/3EV underexposure found under the course of calibration, of which that kind of error is easily and straight forward to correct. Well, I must appreciate that Canon do know very well what they are doing, I must say even they have made some "irregular" thing, IMHO. There is no coincidence or luck in achieving this kind of exposure consistency and accuracy (putting aside the -1/3EV derivation, the metering is dead accurate). The only phase I can describe the whole case is "precise engineering" and also "careful design", by Canon.

But the "Super Precision" Focusing Screen does have its killing problem, which is already told in the 5D instruction manual, this screen is designed for fast lenses with a maximum aperture larger or equal to f/2.8. In fact, I found that the finder image is already somehow dim at f/2.8 and at f/5.6, it is terribly dark, which just makes the viewfinder almost not usable, even just for framing it is bad. The MF focusing using the screen is precise, as what it is claimed and named, but at anything beyond f/4 is almost useless. So, no matter how precise it will show the actual focus (in-focus and out-of-focus regions), it is of no use just when there is no light (or just enough light) that can be seen!

So, here comes a third option from Canon, it is the Ee-D Focusing Screen with Grid Lines (Eg-D for 5DMkII). Although in the 5D manual, it is told that the "Ee-D is essentially an Ee-A with grid lines", I found this statement is actually not correct. With fast lenses and wide(r)-opened metering (in the case with EOS lenses), it is true that there will be no big differences, but when stopped down, the differences show up gradually! Look at my calibration results below for the Ee-D screen and you will know what I say:-

Table 2: Exposure Errors of Canon 5D Grid-type Focusing Screen Ee-D (Eg-D for 5D MkII)

Aperture * :
Exposure Error :
(+ve means over,
-ve means under)
Corresponding EV
Compensation Required :
Not Required

*Remark: Values Not Absolute, different lenses have different light transmitting efficiency and could affect the "centre" f-number. The above table shows the results of my Pentax FA*43/1.9 Limited on 5D.

In fact, for this Ee-D screen, the exposure errors are still quite small for the most commonly used aperture values, which is quite usable even without any EV correction, throughout the range of f/2 to f/8.

However, the most lovely thing of the D screen is not about its stop-down metering with less inconsistency and errors (deviation is not a good thing anyway). The best thing is that the D screen has the best compromise for its screen brightness and it faithfully reproduces the crucial information for the in-focus and out-of-focus regions. It is at least not worse than what the in-camera electronic AF sensing system indicates, although not better than the "Super Precision" S screen (which is then practically not more usable when the lens is at f/4 or smaller). In short, the D screen is somewhere in between the Standard A screen and the Super Precision S screen, of which both the brightness and focusing accuracy are also somewhere in between (Contrary to what the 5D manual tells - it says both the Ee-A and Ee-D screens are the same, except for the grid lines). And, the grid lines mark is a Bonus for proper alignment and leveling, which can be very useful and handy when I need it (somehow frequently when shooting landscape).

Well, at this point, you may notice that I bought both of the Canon's "special" focusing screens! Yet, the total cost of these two *original* screens by Canon, which were both made in Japan, are still way cheaper than just one 3rd party Katzeye! And, I don't believe the Katzeye will be as accurate as original Canons and there is even not a Custom Function in the camera for properly setting it up.

As just mentioned, there is a Custom Function in the 5D and 5D MkII (which is non-existent in any Pentax DSLR) that when different focusing screen is installed, the corresponding screen should be input under that Custom Function. I have verified that that will set an exposure bias/offset value, with the Ee-S profile selected, an 1/3 to 2/3 EV higher Exposure Value will result than if Ee-A or Ee-D profile is selected. And, the difference will be more if the light reach the photo sensor is less, e.g. with a smaller aperture set and/or the environment is darker. This seems very logical as the S screen is actually darker and has more light loss, so it needs to compensate for the lost light as the total amount of light finally received by received by the photo sensor is less, for the same ambient light level.

Last but not least, my K-to-EOS adaptor has a PCB with chipset that cheats the camera a f/2 lens is mounted. I don't know if this will affect my calibration results shown above if a different PCB of a different f/number is encoded. But I think the difference would be small as the other values I have seen for different PCBs/chipsets are of f/1.8 and f/2.8 only. Anyway, YMMV.

Thursday, January 22, 2009

Two Important Custom Functions for Proper Metering

There are two Custom functions (CFs) in all Pentax DSLRs which many new users (or even more experienced old ones) are asking about frequently. They are the CFs of "Link AF Point and AE" and "Lock AE with AF locked". I shall explain more below what these two functions are about and what proper setting should be selected for each of the CFs.

1. "Link AF Point and AE":-

I think to be more exact for better understanding, some words should be added for the description, just say if it is called "Link AF Points to the Evaluative Metering", I bet it would be better.

Now, let's look what exactly this CF means. Normally and by default, the 16-Segment Multi-Pattern Evaluative Metering does not take information from the AF system for determining the exposure value. However, if this CF is enabled. The Evaluative Metering will take into account which AF point(s) is/are in focus and which "corresponding" (see more below) metering segment(s) at these point(s) will be given more weight.

So, would enabling this CF help to improve metering accuracy and reliability? Putting aside the in-born deficiency of the Pentax DSLR metering system (which metering levels are much dependent on lens, metering mode, colour temperature and etc., even for the same objects), there are two reasons why this "feature" will not work well:-

(i) Object(s) that is/are in focus is/are not necessary the point(s) of interest, nor, each individual's reflectance it known;

(ii) The AF points of the SAFOX VIII system are not exactly aligned at the centrals of the metering segments. See the illustration below:-

Almost all Pentax DSLRs made since 2003 are having the same architecture as above, except the *ist DL/DL2 and K-m which some of the 11 AF points omitted. As you can see, only the dead centre metering segment has its AF points aligned exactly, whilst for all the remaining 9 surrounding metering segments, the "corresponding" AF points are not aligned, and some are even at the dead corner of the metering segment. And, there are still 6 remaining metering segments which do not have any AF point to cover.

Furthermore, the issue gets more complicated when the user selects an AF point manually or just let the camera decide for it. Just say if the user (as many users are) selects only the central single AF point most of the time, weight will only be given to the centre metering segment, but anyway it is *just* the basic assumption made by the Evaluative Metering, regardles of what AF point(s) the user/camera chooses. Afterall, the evalutive meter always assume the subject is in the centre of the frame, unless the CF "link AF point to AE" is enabled. If this is the case, and if the camera is let to select the AF point(s) (depending on the model, one or more AF points will be selected (e.g., the *ist D would select only one AF point whilst the *ist DS selects more than one point, as indicated), then those selected points will be given top priorit(ies) in the Evaluative Metering calculations.

After all the above explanations, I think the only case which the above Pentax CF should be enabled is only WHEN the Pentax DSLR is put into Auto AF point selection mode and the user does NOT recompose. This is the only scenario that the Evaluative Metering will do its job correctly as only under this scenario all the *preliminary* assumptions made by Pentax are valid. But do remember that the *assumption* of a subject is in-focus should be given more weight in metering does NOT usually hold - just imagine about taking landscapes, e.g., everything in the frame are at infinity and thus they should be all in-focus, so?

2. "AE-L with AF locked":-

As continued from the last part, the issue gets even more complicated when the user uses the AF lock and re-compose. If this CF is enabled, just say with a single AF point in Single-AF mode, the measured AE value will automatically be locked once the AF is completed. On the other hand, if this CF is disabled, once upon recomposition, the calculated Evaluative Metering value once again could be wrong, as the measured exposure value is Not Locked (but then this is by default), since the central metering segment of the evaluative metering is now pointing to another subject other than the interested object. If the user selects the Multiple Auto AF point mode and recompose, again, everything would be meaningless *just because* the AE is not locked and he/she recomposes, again! (but default it is!)

In fact, all the old days Minolta AFSLRs with multiple AF sensors (since the Dynax 7000i), some Pentax Z model AFSLRs, and every Canon and Nikon DSLRs will have AE locked by default or compulsorily when their cameras are put in Evaluative Metering mode. For many of them there is not even a CF to disable this for the Evaluative Metering. This leaves alone Pentax who just overlooked the problem and thus many Pentax DSLR users have been receiving more errors in the photos they took just because of this "simple" oversight.

Fortunately, the description of this CF is somehow clearer than the above one and at least it is more easily understood by most. As I have just said, I think this CF should be enabled by default, especially with Evaluative Metering, no matter which AF point or what AF point selection mode is selected. To de-link the AE lock from the AF system (after AF is to be locked) is just an *unique* oversight by Pentax indeed, which opens up this option is almost meaningless, for most users and will just create more troubles with even more exposure errors, which holds 100% true for the Evaluative Metering, at least.

If Centre-Weighted Average Metering is chosen and when the Single AF point at Central is used, enabling this CF could give more convenience for avoiding pushing the AE-L button all the time before recomposing. Well, this time it can be well assumed that the subject which is focused is just the point of interest, in this case! As for Spot Metering, since precise "circling" of an areat and careful selection of mid-grey objects is required, enabling this option may not be as practical, though.

Since Evaluative Metering is the default metering mode which is designed and aimed to be fool-proof. I highly urge Pentax to change their default CF setting, so as to be truly fool-proof, for the only reason, merely.

Least but not least, I must mention about the poor and unclear documentation which is also the culprit of creating the troubles, in addition to the inappropriate default setting. All the Pentax DSLR user's / operating manuals are simply poorly written IMHO, which the users could by no means know more about the actual practical meanings (not even to talk about more in-depth) technical knowledge) about many features and functions of their cameras - and of course, better appropriate modes and settings could not be selected by many novice (or even some more experienced) users, as a result. Afterall, all the confusions and inaccuracies show how unthoughtful Pentax really are. In contrast, my Canon 5D has far more thoughtful default settings which are more logically put as well as better documentation, which the difference is clear and has been shown. If anyone who is unconvinced, just go to the Pentax and Canon official websites to download some of the user manuals to compare!

Tuesday, January 20, 2009

AF Speed Difference of K-m Vs K20D

A Korean site has done a head-to-head AF speed test for the two bodies. The test was carried out with the same lens, at the same indoor environment, at nearly the same time and by the same person, two video clips are contained in the following link for the test and the difference is clearly demonstrated:-

http://www.popco.net/zboard/view ... rl=PENTAX_K-m_5.htm

As we can see, the "flagship" K20D just hunts very seriously and the AF could only be achieved after a long time of struggling *all the time*. The K-m is much better there, at least it does not hunt much each time and the AF is done more quickly.

In fact, this problem is what I have been "bashing", as accused by those really silly brand fanboys, for years since the first Pentax DSLR, the *ist D, was created. After which, each Pentax DSLR model I have owned / used / tried is of no difference in such totally annoying AF behaviour, namely, *ist DS, *ist DL, K100D, K10D, K200D and K20D.

Nevertheless, for what I tried the K-m, it hunted less but the AF accuracy was not verified. Anyway, it would be better for the camera to stop those longish huntings and let the user to take the photo before the photo opportunities went away even if the photo comes out to be a bit out-of-focus (just in case), which is surely better than none and nothing delivered!

In fact, Pentax should have resolved this super annoying AF problem which have hurted their DSLR users much (as they would have already missed too many photo opportunities and in fact shooting in moderate low light conditions with Pentax DSLRs have just been a real pain). This in return hurted Pentax themselves, i.e., their sales, just look at their pathetic sales results in the last year and it says it all. Of course there are much more than one persistent and annoying problem which Pentax needed to solve. But, for just letting one simple but important issue like this to exist and be persistent for half a decade is simply a totally amazing thing but yet it is unforgivable. At the end of the days, I must repeatedly point out once again that this silly AF hunting problem did not and does not exist in my $180 Pentax MZ-30 as well as my true flagship MZ-S Pentax film SLR, which has the SAFOX VI and SAFOX VII respectively. What makes alone the SAFOX VIII for being so problematic and requires a such a mercyful lengthy five years to debug it??

As long as the Pentax infamous AF problems are concerned, the next problem which have to be addressed is the yellow light front focusing problem found in most Pentax DSLRs, I must say (including the K20D and don't know if the K-m would be the same). I would expect well that particular Pentax fanboys will come up yet again in defending and arguing endlessly for problems are non-existent, together with unreasonable personal attacks in the end anywhere at any Pentax places, like they have been doing for half a decade, as long as Pentax are unable to eliminate any problem, despite that most facts are clear with solid evidences shown and actually are nothing arguable (just like the above AF hunting problem).

I actually hate much about the silly behaviour of those stupid fanboys as they do no good to Pentax but just harm the brand when Pentax's products become lagging and lagging more and more behind in the competition. I just can't understand why they are so brand-blinded. Well, I bet they will not take more successful photos as others who could face the reality and learned/knew more about the facts, i.e., the gear shortcomings, too.

Thursday, January 08, 2009

My Samsung NC10 Review, Tips and Tricks

Since I am just a big fan of Pentax ;-) and Samsung being an alliance of Pentax, I chose the Samsung NC10 as my new Netbook. I pre-ordered it in fall November for the first lot of NC10 that arrived in HK. My unit arrived in early December, after I had waited for one week. After using it for more than a month now, I wish to sum-up its pros and cons according to my practical experiences here, as well as to share some tips and tricks of my own. The tips and tricks are useful to make the machine easier to use (for changing some various default factory settings, at BIOS and in Windows) and to perform better and more accurately (particularly I shall concentrate on the screen colour/grey accuracy which is important for photo applications).

The Pros:-

1. Large usable keyboard with good keystroke feel: The key size is very large for a netbook. The layout, placement of key and size of each key has been well thought. The reaction force of the keys is good and there is a "crisp" sound for the keystroke too. The top surface of the key is finished with smooth coating but yet somewhat matte looking. Whilst the appearance is good, practial it is not so easy to become dirty and cleaning will be easy.

2. Elegant look, both inside and outside: With a thick surrounding silver rim, Samsung creates an unique style and symbol of their own which from a distance you will know this one is a Samsung notebook. I got the white version of the NC10 btw. The white version has pearl white matte finishing (but yet smooth, similar to the keyboard) both outside and inside. On the other hand, the black version has piano glossy finishing outside and carbon grey matte finishing inside and for the keyboard. As I don't like the inside appear of the black version, I chose the white one.

3. Surprising very long battery life but yet still overall high system performance: I must say the NC10 is a real workhorse, I have no problem with general word-processing and mobile internet application for going out for a whole day, for more than 8 hours, oftenly. Quite often, I used my netbook on and off for about 1/2 or 1/3 of the time during the day (at Cafe, during lectures ;-), on travelling, etc.), battery juice stil remained all the time when I came back home and this is really nice. This netbook, with a 3.5G mobile internet service that I subscribed, has helped me to save a lot of time at home for doing office works and internet writing/surfing. The practically very long usable battery life with a single battery pack really helps a lot here.

4. System performance is very high, despite of the long battery life (I think thanks to the brilliant power management and system performance optimisation). Good job, Samsung! Digital TV application TotalMedia with an Asus U3100 Mini HDTV stick plays very smoothly for MPEG2 SDTV broadcasts (DVD quality). It drops much frames for true HDTV broadcast programmes, though (MPEG4 or H.264 in 1920 x 1080), but then it is normal for a Netbook with an Atom processor and just an integrated Intel display chipset.

5. Loud speakers for a netbook, although sound quality is just so-so (but again normal for a netbook). I have no problem to play video clips in a restaurant (with some background noise, not too noisy, fortunately) and all the audience (about 10) has no problem to hear the sound by just sitting at their own seats at a round table.

6. Bright Screen with True Dark Background: The screen brightness can be set to very high, there is no problem for working outdoor even under the bright sky. The screen background is in deep black colour and hence a high Dynamic Range can be achieved (which is aka Contrast Ratio - the amount of difference between the darkest and brightest tones that can be displayed). I noticed that the NC10's monitor's background colour is much darker than the HP Mini 1000 when I compared them side by side, with the same photos displayed. The few comparable netbook screens with the same both high level of brightness and deep darkness includes the one used in the Lenovo S10, for what I found hands-on.

Unless the sun directly shines on the screen, the NC10 screen is always bright and contrasty enough. The matted screen helps to improve visibility under bright conditions or just when there is lighting overhead which reflection and glare will appear with glossy screens. The image sharpness of the display is not as sharp as glossy screen, though. We can't get the best of both world afterall and it's just a compromise. But I do think Samsung has made the right choice here - the screen is of no use no matter how sharp it is when there are reflections and glares which hinder viewing, especially for a netbook which is used outdoor and at different locations where the conditions are not controllable.

7. Cold machine when working: The heat drain and dissipation design of the NC10 is indeed very good. It does feel cold or just a little bit warm for most parts of the netbook (above and underneath) most of the time. This explains why this netbook has comparatively very long battery life than its competing models with the same 10" and 6-cell batteries. It converses battery energy well and other test reports do show that the battery life is far more than doubled than other 10" netbooks with 3-cell batteries.

8. Overall high performance for peripherals: The harddisk is silent and speedy. The wired and wireless LAN connections are fast and stable too. When it is compared with my other notebooks and desktop PCs, the NC10 does excels in every aspects, both in performance and stability.

9. Acceptable Portability: Size is typical for a 10" netbook. Although it is not the lightest at 1.33kg with battery, the battery pack is a full 6-cell one instead of a 3-cell one which has considerably less capacity and hence shorter battery life. But as I have said, for such a portable device, long battery life is crucial. Thanks to the superb power conservation of the NC10, I feel it is very worth to carry the extra weigh of just about 100g or so.

10. Price: At less than $400, I think this is just a real bargain. What else shall we ask for?

The Cons:-

1. Although the screen is really bright, it is rather inaccurate in the displayed colour. It looks blueish all the time, more so for the mid-tone although less for the bright white. I have checked a few NC10 demo units at different shops and they all look the same. Ditto for most other "LED backlit" screens of other models by different makers. I would confirm this to be a common issue for the LED backlit technology and actually many netbook users have reported that also (see this and this for examples). Even an expensive Sony X-series Bravia HDTV with latest LED blacklit technology just looks like the same - A female friend of mine (who knows little about gadgets but just the name Sony :-)) recently purchased a 46" model and when I went to her home and the first time the TV was turned on, I was shocked about the terrible colour cast I saw - super blueish, no matter for TV broadcast or PC screens. In fact, making a white LED is not easy and various technology barriers have been overcome but yet the technologies involved are not yet matured IMHO. I would not go into further details as those would involve Quantum Physics and Electronics ;-)

Anyway, I shall talk in the next section for more details on practically how such a blueish LED backlit LCD screen could be adjusted and calibrated so that the screen will look better and be more accurate in colour reproduction.

2. Easy scratchable silver mirror rim, although it is good looking: Actually, there are a few scratches already for my newly out of the box NC10. The box is sealed with factory anti-tamper adhesive tapes so I am sure my unit was brand new item. However, the silver shiny surface was not covered and thus there was no protection of any kind out of the factory. I accepted the (minor) scratches as it is difficult to get another one as every unit was pre-ordered at that shop, which was already a large one (the Boardway, Hong Kong). Anyway, just after a few uses, there are even much more of new scratches, despite I did handle my unit with particular care for the first few days. This good-looking mirror surface, whilst is fancy and beautiful, it is not tough and durable for practical use afterall. Anyway, if you just don't look at it intentionally, you might not be able to see all those scratches!

Also, as any mirror surface of those electronics gadgets, fingerprints are easily attached and appear on the surface which will make the surface not good looking, neither. But yet if we don't look at it intentionally, we will not see them!

3. Bundled software is buggy and/or not setup properly: The bundled McAfee Security Suite (90 days free trial) cannot be registered because there is a stupid bug which no matter what password I set and typed in, the registering program did not accept it!(?) I called Samsung helpdesk (but not McAfee'a agent, although I also had their contact number), left a contact, but then no one has replied to me then. Well, this is just a software issue anyway, and also a software by 3rd party as well;

4. Useless customer services: I actually called Samsung two times for the McAfee registering failure issue, the first lady was too innocent for what I described and she just did not understand most of what I reported afterall. So I gave up and called after a day for a second time, the guy who responded understood well what I said very shortly (as it seemed to be). He asked my contact, I gave him and then Samsung never came back to help me after that, then! Both helpdesk staff were very polite, though. But the key point is that Samsung is *helpless* in the case and their customer "service" and "support" is useless.

Pros with Cons - The VGA Output Port for External Display

I want to mention something about the built-in VGA port for external display function. First of all, this port, as in most (or all?) other netbooks, does not have a pair of screw locks for fixing the VGA connector, which could be a problem for broken connection sometimes when the connector is pulled accidentially. Besides, there are flexible display options for setting up the external VGA port. There are 3 modes: 1. External monitor only; 2. Simultaneous display on both internal and external mon by cloning the display of the netbook mon.; 3. Display in "Dual Head" mode, i.e., twin monitors with individual displays.

Once the VGA port is used, the NC10 will automatically switch to a 800 x 600 resolution. The image on the NC10 screen will be elongated, horizontally (since the native horizontal resolution of the screen is in 1024), but however, with a 4:3 external monitor, the display will be correct. The VGA output quality is quite good, I found the image is very sharp and well defined on my Panasonic Plasma TV (it is also needed to be put into 4:3 mode), with accurate and nice colours. But the cons are: other than that 800 x 600 default resolution, I could not find any other resolution setting that can fit my external screen. It is because of two reasons: 1. The NC10 does not support any display resolution higher than 600 vertically, which is just a waste of resolution when it is output to external large monitors, which are usually having much higher vertical resolution; 2. The native resolution of 1024 x 600 is of uncommon and non-VESA standards compliance, nor it is in the popular 16:9 aspect ratio but actually 16:10. As such, it cannot be used in displaying 16:9 pictures in correct aspect ratio. Anyway, this is a common issue for most 10" netbook, except this BenQ Joybook Lite U101 (but I don't like its glossy screen and actually I have not much confidence in the brand, neither).

Tips and Tricks:-

1. Make "better" default settings in the BIOS: To enter the BIOS setup, you need to hit the F2 key quickly a couple of time during startup. Under the "Boot" tab, I changed the "Brightness Mode Control" to "User Control" rather than "Auto", which is the factory default. If it is set "Auto", at everytime the NC10 boots up, the screen brightness will be at minimum, which I regard as an annoyance. The "User Control" setting will remember the last setting of the brightness level which I think should be the way to go. Similarly, another setting I changed is the the "Wireless Device Control" which by factory default it is enabled at every boot, but I would rather to set this to "Last Status" so as to save battery power and to minmise EMI (and for better wireless LAN security too since I normally turn the wireless LAN off unless I need to use it).

2. Adjusting and the display colours and screen calibration:

As discussed in the last section, I believe the problem is a common issue of the current technology, the "white" LED backlight light sources are just not true *white* and they by no means are white and accurate enough, nor I found that the response is linear, i.e., the colour temperature is not constant between highlight, mid-tone and shadows, after passing through the LCD "filter".

To tackle the problem, I first tried to use a Spyder2Pro to do a hardware calibration and tried to create and store an ICC colour management profile in hoping that the colour errors could be compensated by a "proper" ICC profile. Unfortunately, the Spyder kit failed as the wizard window in doing the calibration is higher than 600 pixels so that the next button of the wizard dropped below the whole display screen of the netbook which has a screen resolution of 1024 x 600 only. More unfortunately, there is no default "focus" on the "Next" button (or any button) for the software and thus there is no way to hit the Next button by keyboard to go on the calibration procedures unless the mouse is used (which is the only method). So, I gave up! :-(

So, after that, I tried to tune the monitor by my eyes then. Calbrating the monitor using *any* monitor "calibration" programs which use RGB dithering comparison pattern/chart is mostly useless as those kind of calibration software can just adjust the tone/response curve of individual R, G, B channel by *assuming* that the RGB prime colours are accurate by itself. Without an "eye" (i.e. hardware sensor), they could by no means know whether the displayed colours are and how accurate or inaccurate the actual displayed colours are. But since my Spyder2Pro (which has such an electronic eye) does not work, I was forced to use my own eyes by loading different standard colour test patterns and grey scale charts and accurate sample photos (including various ANSI compliance patterns by the infoComm (formly known as the ICIA - International Communications Industries Association) and then used my own eyes to judge, under different lighting conditions, indoor and outdoor, brighter and dimmer and with different colour temperatures. Well, the last fortunate thing is that I dare to say my own eyes are very colour sensitive, anyway ;-D As a side note, I chose all 800 x 600 test charts and patterns so as to fit for the screen's native resolution and a pixel to pixel display of the patterns and images was realised (they are vertically fit 100% and centred horizontally).

But, to correct the troublesome colour cast of the NC10 monitor is not easy, since the amount of blueish cast varies with different displayed levels. For bright white, it looks less blueish, in mid-tone, the problem is more serious. Also, some little Cyan cast can be noticed too (for mid-tones). Indeed, the screen displayed colours look rather strange by default, which the problems are particular noticeable when photos are viewed/edited. Last but not least, the strange thing is for displaying shadows and dark areas, the colour cast problems seem not so serious, again.

The first time I tried to adjust was to change the brightness level (actually it is just the dark level) of individual RGB channels. I decreased and pulled down the B line and raised R and G (with more R), I was able to successfully make the mid-tones and their colours look better but then the low level greys became yellowish and the highlights became more purpleish which yet make viewing look odd again, even just for web browsing. The problem was caused by individual colour channel clippings, near dark and the brightest levels. Look at this screen capture and you will understand:-

In this illustration, I have entered a higher brightness level for both R and G (with strong R than G too) and decrease the Blue level. In real, the following settings could work: R +10, G +5, B -15: The results: The overall mid-tone is retained with some little clipping/colour changes of highlights and shadows, as you can see from the tone curves.

Finally, I ended up to change the Gamma values, with an intention to merge and fix the starting point at total darkness for all the RGB channel for the response curve and ditto for the brightest end point, i.e., the highest level. As discussed above, there is too much Blue and with also with some Cyan cast. To correct the dominated blue, I needed to add Yellow or to decrease Blue. But there is no way to decrease the Blue level as the Gamma of the Intel display driver do not have a value less than 1 for selection. So, the only way is to add R and G at the same time to a new value of Gamma=1.1 for both, which is effectively equal to add Yellow and to counteract the Blue. To remove also the Cyan (which really makes skin tones look odd), I further raise the Gamma of the Red channel to 1.2. After this, actually the display looks somehow a little bit more red but it is yet more pleased to my eyes than had the Cyan tone visible. Here is the screen capture of the current display driver colour settings of my NC10:-

After the above adjustments, my standard test patterns, grey scales and sample pics now look much better. The lowest and highest greys are still able to be displayed too (which the Samsung display hardware by itself has been made quite good and be able to display these, except for extreme values like (grey) Level 4 or 251 and beyond).

Anyway, I still do not totally like the overall colour tone of my calibrated NC10 screen for two remaining reasons, despite that it now looks much better than ever before (and then any other uncalibrated NC10 units, I bet): 1. The mid-tone and the whole image look a little bit brighter than it should be for the mid-tone. It is simply because where the R and G channels are boosted most there; 2. The overall colour temperature is still higher than I like (it looks like some kind of 9300K hardware calibration rather than 6500K which look warmer and more natural - my default colour temperature of my desktop EIZO monitor (the most accurate LCD monitor in my home) is put into sRGB mode (which has the 6500K colour temperature for the standard).

Updated 9-6 - A better default setting at the display driver:

I had actually successfully calibrated my NC10 monitor using my Spyder2Pro with the aids of an external monitor connected to the VGA output port so that I can go through the calibration wizard on the external monitor whilst calibration was made for the NC10 screen.

A profile was generated and the result was good, except that the screen still looks overall a bit yellowish, especially for shadows. The new profile can be loaded by some LUT loading utilities (see the Comments Section below for details with URLs for those). But the real issue is that the LUT will be reset each time according to the Intel display driver settings each time when the netbook is waken up from the sleep mode when it is put idle for a certain period.

So, after more testings and tweakings, I have been able to find a new better set of settings for the display driver for those "colour correction" values at the display driver. This, whilst has some pros and cons over the "properly" calibrated one by the Spyder2Pro in terms of colour accuracy, the best thing is that the colour settings are remain in force as long as the netbook is turned on and it will not be changed even after waking-up from the sleep mode. Here it is:-

Red: Gamma 1.2, Brightness -5, Contrast 51;
Green: Gamma 1.1, Brightness -10, Contrast 51;
Blue: Gamma 1.0, Brightness -15, Contrast 51

As a final remark, these settings are not suitable for an external display that is accurate by itself, e.g., my Panasonic Plasma display which is highly and *very* accurate in colour rendition and tone reproduction. The changed settings are only set in the sole purpose to correct the hardware errors in the incorrect colour reproduction of the NC10 LED-backlit LCD screen and display. The default Intel settings are most suitable, in contrast, for an external display that is accurate. To load the factory default of the LUT, a Reset command of that LUT loading utility should be issued and one of the tools as posted in the Comments Section that support the command line would be the best tool to do the job (just write a simple command line in a batch file and make a shortcut to it at the Windows).

3. Touch Pad Fine Tuning: I disabled horizontal scrolling and some other useless function of the "Synaptics" touchpad, which is feature rich but not much useful practically, to make the short touchpad's usable area much larger by re-enabling the whole vertical area of the touchpad to be useful just a a pointing device. Do note that the touchpad of the NC10 is already short vertically, It think it is very unwise to even reserve a portion of the bottom area for "horizontal scrolling" by default. In fact, it is ironical that sometimes we tend to forget the most basic tool which are readily available but very easy to use: Why not just use the Arrows to navigate?(!)

To change the settings, just go to the Control Panel -> Mouse Settings and then select the "Device Settings" Tab and then click the "Settings" button:-

Next, under the "Virtual Scrolling" setting, disable "Horizontal Scrolling" and "ChiralMotion Scrolling" by uncheck the corresponding two boxes as below:-

And then you will see the following preview for the "Scrolling Area(s)" as below, with the Horizontal Scrolling area disabled:-

Besides, I did also maximise the "sensitivity" (actually the moving speed) of the touchpad pointer and I found that it is more easy to use with maximum speed, owing to the small size of the touchpad:-

Lastly, I maximised the pressure sensitivity of the touchpad to make it most sensitive so that I can use minimum and lightest force to drive the pointer and to do the tapping:-

Last Comments

Afterall, I must say that Samsung have done an superb and excellent job with their NC10, which in my opinion is the best netbook made so far. It seems that Samsung have been doing much better with their computing and all other consumer electronics products including mobile phones, TVs or even DCs, etc.). But unfortunately Samsung is not doing well in the DSLR market, especially when their achievements in other areas and products are compared. Well, I think I am just not a customer whom is very difficult to please, although I admit that I am picky :-) (which just mean that I have my insistence on some of my essential user requirements - not much different from many others). As long as the gadget makers have done good enough and be better than the average Joes who just produce mediocre products, I will be satisfied.

Well, anyway, when will Pentax (or even Samsung) develop and make similar competitive or even strong/leading product(s) in the DSLR field and for the DSLR market??

P.S. This is the first time I write a review on electronics gadget other than digital DSLR gear and related stuff, I hope anyone who have read this review do like my review and find it useful! See you next time.