K-s2 and HD DA 18-50 Specs

http://photorumors.com/2015/02/09/pentax-k-s2-camera-hd-pentax-da-18-50mm-f4-5-6-dc-wr-re-lens-specifications/

Not bad.

Pentax has Modified the Design of the SDM Used in DA*16-50 and 50-135??

See the latest quick interview by the PF with a Pentax repair technician at Photokina:-

http://www.pentaxforums.com/news/jens-petersen-on-pentax-sdm-failure.html

Whilst I am rather sceptical to what are told, even if all of them true, the following questions have quickly come to my mind:-

1. Why it takes so long, i.e., for more than five years, for Pentax to cure this problem? It is worth noting that the two DA* lenses were first launched back to 2007!

2. If it is just a design problem for all those reported failure of the SDM, aka Sudden Death / Suddenly Died Motor or Saddam as creatively named by some users before ;->), which is yet "prone to failure from the get-go due to their design", WILL Pentax Ricoh make a product recall and fix the earlier production lenses prior to 2012 which have that latent design defect, *for Free*?

3. I could never agree that the DC motor is of the same design of a conventional rotary electric motor (DC or AC), they are different! To learn more, just read my previous technical article about the working principle of the DC motor and its related patent.

Well, as an UK chartered electrical/electronic engineer myself, I don't believe in "technicians" when they are talking about designs. Note that I am not saying anything bad about technicians but their knowhows are mostly limited to hands-on things, but not about designs and more in-depth engineering principles, frankly.

Indeed, see the reply comments to that PF article, Pentax users are actually raising similar questions as mine! :-)


Last Related:-

Improved DIY SDM Repair Method!

DA560/5.6: New Type Built-in Motor, Astro-tracking, US$3800

Via Post @ Pentax Forums

Let me add in more rumoured specs (from another source):-

1. Dividable type in 3 pieces;

2. Simplified weather resistant design;

3. Built-in lens motor (neither SDM nor DC), full-time manual override;

4. To be sold at a suggested price of US$3800;

5. Not a Star lens;

6. Built-in astro-tracer! (Oh, really? :-o)

7. Manufactured upon special ordering.

My Practical Review on the DA18-135

As we all know, this lens received rather poor rating and adverse comments at the PhotoZone and then the official early samples posted by Ned Bunnell did look bad either.

But then stupid fanboys of Pentax like me are actually irrational ;->, I went bought this lens regardless of the poor reputation of this lens all over the Internet! :-o

This time, I am going to write a practical review on the lens, with more real-life photos of mine shown, for what this lens can deliver, on a K-5. You will see how "poor" this lens could be!~

First of all, still some comments of mine in words. As you can see from the above modelling photo, this lens is really compact and lightweight. It has an internal focusing mechanism such that the length of the lens will not change during focusing. And of course, the front element will not rotate.

I am much impressed with the build quality of this lens, which is the best amongst all DA Pentax standard zoom lenses that I have ever used, I would say. Even the bundled lens hood is better built than most of other Pentax', with matted lining inside and the rugged texture outside which contributes to a solid feeling. At the beginning, maybe owing to the weather sealing, when the lens was first opened brand new out of the box, it is very tight to zoom. But then after the first few days of use, the friction and resistance became just right provided that it is not zoomed too fast and too quickly otherwise higher resistance can still be found.

Speaking of the DC motor and its AF performance on K-5, it is fast, moderately accurate and silent although it is not completely silent and some very small sound can still be heard in really silent environments (ditto for the new Canon STM, which I also have). Under the Live View mode and with this DC lens, the LV CDAF is obviously faster than with other conventional type Pentax AF lenses.

Now, let's come to the IQ part, this lens is quite sharp in the image centre throughout the whole zoom range and from wide-opened, here are some various samples (Click to download in Large size, EXIF preserved):-


(18mm, f/3.5)


(18mm, f/5.6)


(18mm, f/6.7)


(21mm, f/4)


(21mm, f/8)


(28mm, f/4)


(36mm, f/4.5)


(36mm, f/6.7)


(36mm, f/8)


(40mm, f/7.1)


(53mm, f/6.3)


(100 mm, f/5.6)



(135mm, f/5.6)

It can be noted that the extreme corner softness is only existent at the widest side at 18mm. From 21mm and onwards, the effect is considerably eliminated and is not that noticeable. Distortion is significantly decreased, too.

In general, images produced are with good colours and contrast. Resolution is high throughout the frame except at the extreme focal ends, i.e., 18mm and 135mm. I do note that my lens' optics are perfectly centred by judging from the vignetting pattern, nevertheless. Maybe I am just lucky enough.

The flare resistance is superb. Look at this:-



The bokeh of this lens is not bad, look at these two (and also some of the above samples with a blurred background):-



Round bokeh of highlights can be seen.



Btw, why to use Live View with a DSLR? (I can see many DSLR beginners have been doing this!) Why not just use a K-01 if so?! :-o

There is one minor problem of this lens (or maybe the Pentax DSLR system in general), it is that it has a slight underexposure tendency, a +0.3/0.5 exposure compensation would usually cure it.

Besides, the Pentax SR system for tele-lens is proven to be ineffective, once again. I have got quite some blurred photos when shot at 135mm, just because the lens speed is slow but SR didn't help:-



All in all, I am quite satisfied with my copy of the DA18-135. It seems that my lens has far better performance than what is shown in the various measurbation tests and I do believe that it is a lens that performs well in real world but not so for measurbations. This maybe owing to the inconsistency quality control (or lenses are actually classified into different quality classes and batches - mine was purchased separately). The other possibility is that the optical design of this lens is not optimised for close range objects, where a test chart is placed and shot.

At the end of the day, this travelling zoom will not give you stellar optic quality which primes could give which is well expected, After all, let's see if my "favourable" review this time could retrieve the confidence of some potential buyers of this lens and maybe also for Pentax the brand as well! ;-D


Related:-

Interview with the Optical Engineer/Designer of the DA 18-135 Lens

What If When a Pentax FF Body Really Comes (My Own Case Study)

Actually, I have been planning to get ready for a Pentax FF system for years and every time I bought a new Pentax lens I had that in mind. Well, below is the case for my current lens setup:-

1. Currently, I have 10 original Pentax primes, amongst which only the DA21 is not FF compatible, so the complete FF range is ranged from 28 to 300mm. The old "film" primes of mine include A, FA, FA Limited and FA* lenses. In addition, my existing three DA primes (namely, 35, 40 and 70) are all FF compatible (see my own samples here and here). In short, there are 9 lenses (out of 10) that can be used on FF!

2. For zooms, I still have 7 Pentax AF zooms amongst which only two DA standard zooms are not FF compatible. Other lenses are F, FA and FAJ ones and the made-up zoom range is from 17mm (fisheye) or 18mm (rectilinear) to 200mm. So, no problem again and I do have 5 FF zooms (out of 7)! :-D

3. I also have two FF tele-convertors by Kenko which is in full KAF2 compliance, i.e., with power zoom (SDM/DC) contacts.

So, all in all, I already have 14 original Pentax lenses plus two fully compatible AF tele-convertors (and also two other Sigma lenses that I rarely used, i.e., 18 lenses in total) to begin with when just overnight a Pentax FF DSLR body appears! Note that most of my lenses are AF lenses and full functions and compatibility is ensured and the focal range has been well covered. That must be really great! :-)) As for new Pentax FF lenses that are to be launched, I am sure that I will not hesitate to invest further if I can see the future of Pentax later on (but not now)!

P.S. If this time the rumour turns out to be not true and still there will be NO Pentax FF by early 2013, I think I might sell most of my Pentax gear and concentrate to build further my Canon system and make it glows. The wait should be over, for more than ten years, shouldn't it and shouldn't I?

P.S.2. I have another 13 lenses for other systems. possibly soon to be 14, when the Canon new pancake arrives!

P.S.3. How about your case? Welcome to share in reply! :-)


Related:-

Compatibility of DA Lenses on Full Frame

Two Major Meanings of Full Frame - Choice of Shallower DoF and Most Optical Quality from (FF) Lenses

Old Question: Will there be a Pentax Full Frame DSLR?

Interview with Hiraku Kawauchi, Head of Marketing of Pentax Ricoh Imaging Japan, by the PF

(URL: http://youtu.be/PP-t4ODEqbs)

This time I think the PF guys have done a good job, they carried out the Interview at the CP+ at Japan and have done the translated scripts. I am not sure if they are actually sponsored by Pentax or not for the trip, but one thing is certain, i.e., now they have close relationship with the official Pentax. Nonetheless, I think they have asked a few good questions that we Pentaxians have been concerning about including some long lasting Pentax issues, somehow indirectly. Putting aside those pure marketing and sales talks by Hiraku, here are some more important points and messages that I am extracting from the interview, quoted and summarised as follows:-

- At 4'30": DA50/1.8 and FA50/1.4 will co-exist.

- After 4'30": Whether the DA50/1.8 has the Quick-Shift Focusing (QSF) mechanism cannot be disclosed! (But nevermind, there is 99% of chance that it won't have! It looks exactly like the DA35/2.4, which is essentially a DAL, but not a true DA!)

- After 7'00": OVF is meaningless and EVF is not present for the K-01! (Well, we all knew about the stance of Pentax since the K-01 was marketed! :-|)

- Before 8'00": Astrotracer (and actually also the navigation) function(s) of the O-GPS1 is(are) not supported on the K-01.

- After 10'00": There is currently not many FF lenses in production and the time-frame for a FF body is uncertain.

- After 11'30": DSLR is still required for higher performance and EVF cannot replace OVF with the current technologies.

- After 12'30": There is no FF mirrorless body on their product development roadmap.

- At 14'10": Pentax productions will not be moved back to Japan. (Yes, we all knew!)

- After 15'00": The DA*16-50 SDM lens will be replaced.

After all, this interview is still worth watching. But I just wonder why after the publication of it for more than 12 hours with email alerts to all PF members, there is only about two thousand watches to the video up to now. :-o So, I think it's time for me to promote it and encourage you to watch! :-) It is just because I think it is still valuable, otherwise I just won't bother to mention it! Nevertheless, marketing and sales talks are always existent in between statements but Hiraku is actually a marketing guy, right?

Supported Pentax DSLR Functions with Different Pentax Lenses

Read this question at the PF and I was surprised to see the reply by the site owner Adam (i.e., the first reply to the OP), which shows that Adam completely lacks the basic user/operation knowledge in using older manual (aperture) Pentax lenses on any Pentax DSLR! :-o

Maybe Adam has been given too many of the latest Pentax lenses (for "reviewing" or whatsoever) so that he has almost forgotten how older Pentax manual lenses would behave on all the Pentax digital bodies. Nevermind, I think it's my take now! Below are two summaries that I compile to let all my readers here know (or got refreshed for the knowledge if already known) about the basic technical features or limitations of our Pentax lenses back to the 60s of the last century and what they could or could not do for us with our Pentax DSLR bodies! :-)

N.B. I don't think that you can find ALL of the information below in any of the Pentax DSLR/lens user/operation manuals! ;-D


Table 1: Lens Data/Function Availability with different Pentax Lenses

Lens Data and/or Function	Provision Means	M42	K/M	_A_	_F_	_FA_	FAJ/ DA/ DAL	DFA (1st Gen.)	DFA (2nd Gen.)
Wide-opened Metering	Instant Return Aperture Coupler	-	Y	Y	Y	Y	Y	Y	Y
Number of Steps Stopped-down (via Aperture Ring)	Mechanical Position Indicator	-	Y	Y	Y	Y	-	Y	-
Maximum Aperture	Array of Electrical Contacts	-	-	Y	Y	Y	Y	Y	Y
Minimum Aperture	Array of Electrical Contacts	-	-	Y	Y	Y	Y	Y	Y
Focal Length	(Advanced/Serial) Electronic Communication	-	-	-	Y	Y	Y	Y	Y
Focus Distance	Electronic Communication	-	-	-	Y	Y	Y	Y	Y
Lens ID	Electronic Communication	-	-	-	Y	Y	Y	Y	Y
MTF Data	Electronic Communication	-	-	-	-	Y	Y	Y	Y
Powered/Auto Zoom	Electronic Communication and KAF2 Power Contacts	-	-	-	-	S*	-	-	-
In-lens AF (SDM or DC Motor)	Electronic Communication and KAF2 Power Contacts	-	-	-	-	-	S	-	-

Legend: Y= Yes/Available; "-" = No/Not Available; S = Supported depending on Lens Model (if Feature is Available)

*Remark: Limited/Partial Function - Only Auto Zoom Retract and Powered Zoom are Supported.


Table 2: Pentax DSLR Camera Function Availability with different Pentax Lenses

Body Function	M42	K/M	_A_	_F_	_FA_	FAJ/ DA/ DAL	DFA (1st Gen.)	DFA (2nd Gen.)	*Remark
Wide-opened Metering	-	-*	Y	Y	Y	Y	Y	Y	Stopped-down metering is available with a push of button.
Multi-segment Metering	-	-	Y*	Y	Y	Y	Y	Y	Not as accurate as subject distance information is Not available (and hence is not included in the calculation).
Off-the-film TTL Flash Auto (*ist D and DS/DS2 Only)	Y	Y	Y	Y	Y	Y	Y	Y	TTL flash sensor underneath mirror is installed; No Pre-flash is required.
Off-the-film TTL Flash Auto (All Others)	-	-	-	-	-	-	-	-	No TTL flash sensor underneath mirror; P-TTL is mandatory for Auto Flash.
P-TTL (where P stands for Pre-flash)	-	-	Y*	Y	Y	Y	Y	Y	Not as accurate as subject distance information is Not available.
AF	-	-	-	Y	Y	Y	Y	Y	-
Lens Correction on Image	-	-	-	-	-/Y*	Y	Y	Y	Only the three FA Limited are Supported.

Legend: Y= Yes/Available; "-" = No/Not Available


Okay, is it and everything much clearer now? :-> And no need to make thanks to me, thank Adam instead! ;-p After all, I just won't make any reply over his premise to help others (and actually help him to make more money!) anymore (although Adam is really "kind" enough for not banning me!), as I decided and told two-and-a-half year ago! :-D


Further/Reference Read:-

K-Mount Metering and Exposure Bases - A Technical Brief

Related:-

Two Important Custom Functions for Proper Metering

Modding a Rikenon-P 50/1.7 Into an "A" Lens! :-o

Ten Things that I Want Ricoh to Do for Pentax

Hypocrites of the PentaxForums and Their Lies

Updating of my Blog Editing Direction

Photozone DA 18-135 Full Review

http://www.photozone.de/pentax/597-pentax_18135_3556?start=1

It scores only 1.5 points out of a total of 5. And so does the price-to-performance ratio. :-o :-( The final verdict of Klaus is quoted as follows:-

"Verdict

We were quite enthusiastic about the Pentax DA-SMC 18-135mm f/3.5-5.6 ED AL [IF] WR at the time we received it. Regarding the high pricing of the lens we were expecting a very good performance throughout its broad zoom range and all that in a very compact, high quality body. Unfortunately the testing reality revealed a mediocre optical performance at best. A lens with a 7.5x zoom ratio may be quite ambitious but other manufacturers managed to design pretty good lenses with an even more extreme range. The Pentax lens is actually very good to even excellent in the image center but the borders/corners suffer from massive field curvature at the wide end and plain sofness at tele settings. This is certainly no issue for portraits and such but you don't really want use this lens for architecture or landscape photography here. This is also in so far surprising because the (cheaper) Pentax SMC-DA 18-250mm f/3.5-6.3 (a Tamron design) was actually very usable here. The secondary characteristics (distortions, vignetting, CAs) are about class-average. A very positive aspect is the build quality of the lens - the lens body is based on tightly assembled, high quality materials and the weather sealing is a quite unique selling point. The new DC AF motor may not be as fast as Pentax' SDM but it's quite fast and comparatively quiet. The biggest problem of the lens is its pricing which is simply not in line with the optical performance. Therefore: Avoid! Better consider the Pentax DA-SMC 17-70mm f/4 SDM instead which is a far better lens."

And, do see also this additional remark made by Klaus at the DPR forum. The reason for why the publish of this lens review is delayed has been talked about. The chance was given to Pentax but the lens was checked to be "within factory specs".


Previous Related Stories:-

PhotoZone DA 18-135 Test Results Will Not be Good (Very Possibly..)

Ned Bunnell's (Official) K-5 + DA 18-135 Samples

Practical Manual Focusing Problem of the DA 18-135 DC Lens

See what this new user of the 18-135 DC lens reports:-

http://www.dchome.net/viewthread.php?tid=981773&extra=page%3D1
(Traditional Chinese, Babelfish English Translation Here)

The problem is that the MF ring of the DC lens lacks a focus scale but in addition, the worst thing is that it is freely rotating in cyclic. The user could by no means do MF (in this case the user wanted to shoot night scenes when the AF failed and was unable to focus) as the focus position is just unknown. In fact, the MF ring of the DC lens is actually a pseudo one, just like those of the micro 4/3 ILDCs and the NEX E-mount lenses, i.e., indeed they are indifferent! :-o :-(


Related:-

Working Principle of the New "DC" Motor (Patent Paper Included)

Does the New DA 18-135 just Look Too Close to the Nikkor Counterpart? :-o

Pentax Completely Abandons Screw-drive Body-AF for All Upcoming New Lenses (If Any!) >:-[

This is disclosed from an interview with the senior officials of the Pentax Imaging, at the recently held New York PhotoPlus Expo:-

http://enticingthelight.com/2010/11/01/speaking-to-pentax-at-photoplus-expo-in-new-york/

Quoted:-

• DC is a new type of in-lens focusing motor that’s intended for consumer lenses. DA* lenses will incorporate the higher grade SDM focusing.
• Going forward, all DA lenses will have DC focusing only, losing the screwdrive option. The exception will be the DA Limited lenses, which will stick with screwdrive focusing.
• The new DC 18-135mm f/3.5-5.6 is DA focus only and will be available within a few weeks (the display unit I tried out is a preproduction model). It is “weather resistant” and has a metal mount. Price will be $530 in the US.
• Still no official statement from Pentax about the SDM failures. I was told Pentax USA was aware of the issues people were reporting, but that it was Pentax Japan who had to acknowledge a problem (if there is one). Pentax USA doesn’t know if the alleged issue is being addressed, but I was told the engineers are continually working on improving their designs so it could be new SDM lenses would be more resilient. As of now, Pentax Japan have not informed them of an SDM II being developed.
• No word on any possible new lenses.

Well.. Oh, NO! >:-{

When some people are always blaming me for being "negative" from time to time. But in reality, aren't all these news are just too discouraging enough? Mind that almost every person writes his/her own words in the Internet now, and I am surely not the only Pentaxian who are being "negative". Do note that the above are all told by the senior officials of the Pentax Imaging of USA. I believe that the author does not mis-quote what the officials said.

At the end of this post, I just can't help myself and just wish to ask: With the drop of backward system compatibility with all the new lenses (which are yet unknown for their actual existence!), why people should go Pentax now? Just because their SDM is known to be particularly superior in performance and more reliable?? Besides, it should be noted that the performance and reliability of the DC motor is yet not proven, but time will tell.

Finally, do note that if they now could abandon the support of those a bit older DSLR bodies that were made only back to 2006 (K100D and before), a few years later they can yet once again abandon the support of the *current* screw-driven DA/FA Limited lenses on their new bodies, which possibly by that time will only support lenses that have an in-lens AF motor in them. So, this would be something that we should really think about..

Indeed, Pentax *was* the company whom once had insisted the most on system forward and backward compatibilities. But now, everything shows that Hoya just breaks this good tradition too easily, but without good enough reasons, which is rather disgusting after all!


Read Also:-

1,000 Signatures of the Pentax SDM Petition Online!

Really NO MORE HOPE WITH PENTAX (Dozen Reasons for WHY NOT PENTAX NOW)

Pentax Starts to Drop Support for Body Driven AF

Does the New DA 18-135 just Look Too Close to the Nikkor Counterpart? :-o

Well, here we go again, let's look at the following pictures of the three "18-135" lenses of Canon, Nikon and then Pentax..





The Canon is obviously of a different design, as it is a front element focusing lens. In fact, the outlook, dimensions and weight etc. of the Canon are much different from those of the other two, too. So, let's compare the technical specs of the remaining two, as follows:-

Lens:	Nikkor DX 18-135/3.5-5.6	Pentax DA 18-135/3.5-5.6
Optical Formula:	15 Elements in 13 Groups 2 ED, 2 Aspherical	13 Elements in 11 Groups 1 ED, 2 Aspherical
Minimum Focusing:	45cm	40cm
Thread Size:	67mm	62mm
Physical Size:	73.5 x 86.5mm	73 x 76mm
Weight:	385g	405g
Other Characteristics:	Rear Inner Focusing, Silent Wave Motor	Rear Inner Focusing, SDM Compatible DC Motor, Weather Resist

Although they are not exactly identical, are they just really close enough? A Coincidence? Anyway, the new DA(L)35/2.4 could be even closer to the old FA35/2, just look here.

Working Principle of the New "DC" Motor (Patent Paper Included)

I am not sure what the "DC" actually stands for in the official marketing media article of the new DA 18-135 DC. But typically DC motor just refers to Direct Current Motor after all in technical sense.

But then the above press release also mentions about its "SDM autofocus operation" (but the lens now has no SDM designation btw), so now I take and (re-)understand SDM just only means Silent Driving Motor then, in contrast to previously told long form of Supersonic Driven Motor or whatsoever / whatever you or the Pentax marketing guys like to call it!

Below maybe the patent and detailed design that used in the new lens for that "DC" "ring-type" AF motor, have a look, it is not too difficult to be understood if you really want to study:-

http://www.freepatentsonline.com/20090323208.pdf

In short, it is just a "conventional" DC Motor with magnets arranged in ring-form, continuously and in cyclic, which is yet somehow unconventional then, as those permanent magnetics are now arranged "outside" the core/coil of the motor (in certain sense), but not inside in a self-contained unit and then the self-contained motor is used to drive anything "outside" as desired by/thro./via gears. As such, this new DC motor is simply nothing Ultrasonic and the working principle is totally different.

I would say it is a very clever design with low and old technology used. Let's see if it will perform and if it would be more durable than the old SDM motor units, which are proven to be rather vulnerable and slow which are just helpless, frankly speaking.

Putting aside the speed/performance issue, the other major concern is about its AF accuracy. My judgement is that if the motor has minimal inertia, then its focusing accuracy will be good. Otherwise the servo control and algorithms of the AF must be designed and written to be very good for the control model for a targeted/desired stop-down (curve) . The old SDM is proven to be not accurate for the stopped position and thus focusing accuracy is affected and sacrificed (which is actually worse than the old body-driven screw-type AF). Now, there is hope in the Pentaxland again! Let's see if this cleverly re-designed motor using the most primitive and old technology will work, or not! :-o :-)

Anyway, last but not least, I feel happy to see Pentax/Hoya really have done some R&D of their own. And most importantly, to realise their R&D results and put them into their new products! :-))

Your Reactions About the New K-5 and DA 18-135 WR Kit Lens?

As we have known that for quite some time now, the new body and lens have been announced. Just See the Official English Hoya Press Release Below:-

http://www.engadget.com/2010/09/20/pentax-k-5-brings-16-2mp-sensor-much-faster-af-and-enhanced/

w/ the Body Images Here

And the new lens is Here! DA 18-135/3.5-5.6 ED AL[IF] DC WR - Wow! Any Longer Suffixes?! :-0


(Source: http://www.videoaktiv.de/images/2010/Pentax/DA_18-135mm.jpg
@ http://www.videoaktiv.de/201009204913/News/Foto/Pentax-K-5-D-SLR-Kamera-mit-Full-HD.html)

From the Above, do note that it seems that this lens has Rear/Inner Focusing mechanism as the focusing ring is just at the rear..

Update (22:00 UTC+8): DPR posts their lens announcement with the K-5 announcement!

http://www.dpreview.com/news/1009/10092019pentax18135lens.asp

http://www.dpreview.com/news/1009/10092020pentaxk5preview.asp

Moreover, there is a first video interview at the www.fowa.it, uploaded at the YouTube:-
http://www.youtube.com/watch?v=EcnmEZQhX2s

Whilst you can find at the DPR for a brief hands-on preview here and a summary of most of the announcements and reactions at the 1001 Noisy Cameras eventually, I yet once again raise a poll here, just like what I did last time for the K-r and the "new" DAL 35/2.4 all plastic lens.

So, it's your take now, here it is!

What Do You Think About the New K-5 and Kit Lens (DA18-135WR)?
	Excited (Very Interested)
	No Feeling (Neutral)
	Disappointed (Not Interested)
pollcode.com free polls

Poll Page URLs:-

Vote: http://poll.pollcode.com/lBV
Results: http://poll.pollcode.com/lBV_result