Wednesday, September 24, 2008

New DA 17-70 F4 Lens Test

Have just seen this new review and test of the lens:-

http://www.digitalcamerareview.com/default.asp?newsID=3676&review=pentax+17-70mm

As you can see from the crops of the "newspaper" testing shots that:

- At 17mm, there are serious light fall-off, obvious and large amount of barrel distortion, significant edge softness and blur at image corners. The sharpness could only be partially improved until it is stopped down 4 steps down to f/16 (well, stopping down two steps to f/8 still don't help much). And, the vignetting becomes less obvious at f/8 but however is still visible;

- At 70mm, there are still serious light fall-off, significant edge softness and blur at image corners. Again, the sharpness could only be partially improved until it is stopped 4 steps down to f/16 (and again, stopping down two steps to f/8 won't help much). And, the vignetting becomes less obvious at f/8 but is still visible. There is no obvious distortion at 70mm, though.

So, if this new DA 17-70 F4 lens is now being sold for doubling the price of the old DA 16-45 but could even have (much) worse optical performance, then it must be yet a big joke that Pentax are making to us. Not even to mention that this lens is not compatible with all the just older Pentax DSLR bodies for not supporting the body driven AF, although it now has SDM (but only).

Well, I just can't help to ask Pentax/Hoya again: What's going on? (???)

11 Comments:

.mario said...

RiceHigh, can i copy-and-paste the conclusions of the review?

"With excellent contrast, nice color handling, and improved CA control, the 17-70mm is capable of superior shots, especially in the context of landscape shooting. Several days of intense outdoor shooting with the 17-70mm, and the very pleasing shots that resulted, are a testament to just how good this optic can be. Compromised sharpness throughout at wider apertures will be a sticking point for some, which is a shame really: for certain kinds of shooting, the 17-70mm works quite well.

Given just how good Pentax's current-generation 18-55mm kit lens is, however, a bigger concern may be whether the 17-70mm's $600 price tag makes it a worthwhile upgrade. The more expensive lens buys you a little bit of speed at the telephoto end, and a little bit of range; when sharpness is firing on all cylinders at narrower apertures, there's simply no comparison between the two. The concern, though, is that for lots of general, walk-around shooting (which implies, at least, the lack of a tripod, and thus makes narrower apertures a challenge depending on light), it may be hard to realize the benefits of the more expensive glass.

The 17-70mm should appeal to architectural and nature photographers without question, and might even serve well as an urban shooting or general purpose lens, but even with all of the progress that Pentax has made in this series to improve build quality and correct wide-open aberrations, the adherence to a slow-at-the-wide-end f/4 constant aperture and nagging questions about sharpness leave us feeling a bit tossed up about the 17-70mm at the end of the day.

Pros:

* Excellent build quality
* SDM focusing is quiet, fast
* Constant f/4 aperture
* Beautiful contrast and color

Cons:

* Sharpness leaves some question marks
* CA still apparent at times
* Nasty barrel distortion at 17mm
* What's with that short focusing throw?"

Maybe not terrific, but not so bad, isn't it?

So, I just can't help to ask you: What's going on?

Anonymous said...

I just love your work Ricehigh! I thought I would include an excerpt from a review of the Canon 5D

http://dcresource.com/reviews/canon/eos_5d-review/index.shtml

* Expensive
* Requires nice lenses for best results; EF-S lenses not supported
* Slower continuous shooting mode than EOS-20D
* No built-in flash
* No AF-assist lamp

This must mean that the 5D is absolute rubbish!!!

RiceHigh said...

So, what about all those image problems *shown*?

Anonymous said...

There is no such thing as a perfect lens. All lenses have their pros and cons. Even the best lens in the world would have a con - Price!

If you had any sense of objectivity you would have included the positive aspects as well. You didn't as usual.

RiceHigh said...

Do I ask for a "perfect" lens?

Large amount of distortion, serious edge blur and softness and vignetting throughout the whole zoom range, stopping down to f/8 won't eliminate much the problems!

Price? Are you kidding? Go figure about the *price* of the DA 17-70 yourself for *such* a lens. Do *remember* to compare against the price of the old DA 16-45/4!

You boys are really always amazing as far as "objectivity" is concerned!

.mario said...

Apart from price, since you have to wait for real street prices, the thing who concern people is that in your comments 95% of them are negative and against PENTAX. If so, the only choice is to jump away from Pentax and hug Canon or Nikon!
If you stay, relax and calm down, write posts about "my 5 best pentax lenses ever" and similars, and be patient: i can remember very well at PMA 2007 when Sony had only mockups at its stand; only C and N can have tons of new products each time at PMA and Photokina... if you need to be constantly knocked with new products and you can spend a lot of money each time, ok Pentax is not for you! Personally, i bought my K100D in Jun07, maybe i'll buy a 2nd dslr in l009, but i cannot buy a camera every 6 months...
but definitively i hope there's somewhere a Ken-Rockwell-for-Pentax somewhere, with a blog to read!

Anonymous said...

I completely agree that the lens should be cheaper. But to be fair the price is very reasonable to the 16-45mm. 16-45mm sells for 399.00 USD now and this one sells for 530.00 USD. (at B&H) The difference is not that great. They are both overpriced if you ask me, however.
Regarding the test though, I would say, wait for more reviews. If more than one reviewer shows the same problems, then yu may draw a conclusion, but now, there is not enough evidence to proof anything.
You may also test the lens yourself, and compare it with the quality of your praised Pentax glass, test it against your favorite Canon equivalent, then draw a conclusion. Untill then, this is meaningless.
Regrading the vingetting, it is very easy to fix in the post processing, and thus it is one of the least problems.
Looking at the pictures on the test page I also question the focus acuraccy of those images.
Also has this reviewer reviewed the 16-45mm lens, that would be interesting to compare to this one.

Anonymous said...

GREAT review... for someone who has not used the lens. Is this what you do? Take other reviews and then comment on them without any original work of your own. What value has that? I can read. I don't need you to interpret for me. You hardly seem to have a balanced approach let alone a balanced mind. Thanks. Keep up to the good ... er... the work.

Anonymous said...

Take a look, Mr. High on Rice:

http://tinyurl.com/dkzlsn

-- asdf.

Anonymous said...

One if not the most respected site for lens reviews, photozone.de tests very accurate and says:

http://www.photozone.de/pentax/408-pentax_1770_4

"Verdict
The Pentax DA SMC 17-70mm f/4 AL [IF] SDM is undoubtedly the most desirable standard zoom lens in the current Pentax lens lineup. The resolution characteristic is very good without any significant weakness....All-in-all a very harmonious package selling for a very fair price of around 480€/US$."

Anonymous said...

Ther is so much money involved in reviews that I don't beleve them anymore. I have tried this lens!
My conclussion: It's the last time that I read one of your reviews!

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