DA* 16-50mm Serial Number Database. - Page 8

jsherman999 · 07-14-2008, 11:22 AM

That's a 100% crop? Can we see the full image?

Note that @ 50mm + f/2.8 is this lens's weakest spot - Need to see the whole image,
but I'm thinking it's probably OK. Especially for a 100% crop...

fishy · 07-14-2008, 12:49 PM

Sorry, my bad, was no 100%. Misread dimensions...

But I think you're right. I also have a really soft Sigma 28-70 2.8, but I don't use it anymore. Maybe I'm too careful (or worried, it'd be hell to send it back to the States)
Next try (image converted from RAW, no sharpening):
Focus is on the grey-ish book, 'Ethica' for the top, 'Dover' on the bottom crop
Top: Center-center, Bottom: center-bottom

The girl was taken @ 50mm, 1/100, iso 100, the eye is a 100% crop (really, this time)

So where shall I put 9029381? Good or bad? I'm still not decided

Classvino · 07-14-2008, 02:11 PM

9014806 seems OK - no strenuous testing yet, but test chart looks good...

Bought at Henry's, Kingston, Ontario, Canada

augustmoon · 07-16-2008, 11:57 AM

Wanted to wait a while before posting, to make sure

9011905 - Good

Aden Camera (new), Toronto, Ontario Canada

AF is correct on K20D (no Bf, no FF with no AF adjust applied on camera)
Not de-centered (center of focus is center of image, left and right OOF area equal)

truonganh · 07-16-2008, 01:08 PM

that looks on par with my fast fifties at 2.8, fully cropped.

anyone think it's bad, i like to see a 'good' example in comparison.

fishy · 07-16-2008, 01:30 PM

Originally Posted by truonganh

that looks on par with my fast fifties at 2.8, fully cropped.

anyone think it's bad, i like to see a 'good' example in comparison.

Thanks, been fishing for those myself. (if possible black print on white paper.. )

fishy · 07-20-2008, 07:33 AM

Just to check; should the DA16-50 be outperformed by the FA 50 2.8 @ f/5.0? (Mine is

)
Voting 9029381 bad

TanGU · 07-21-2008, 10:24 AM

How can you know BEFORE buying the lens if it is good or not !??!?!

jsherman999 · 07-21-2008, 12:20 PM

Originally Posted by fishy

Just to check; should the DA16-50 be outperformed by the FA 50 2.8 @ f/5.0? (Mine is)
Voting 9029381 bad

??? Yes, by all means, the FA 50 f/2.8 should outperform the 16-50, at f/5 and even f/2.8... Did I understand your question correctly? A prime will almost always outperform a zoom, especially the FA 50 2.8 macro, which outperforms pretty much anything.

fishy · 07-21-2008, 12:26 PM

...A prime will almost always outperform a zoom...

In that case I might have to review my verdict; The da* @ f/5.6 at least matches the FA50 @ f/4.0 in crispness/sharpness. I might have been thrown off by bright light and hard contrast; my DA* suffers a lot from purple fringeing. Less light and it gets better.
One bad of mine: the FA is not the macro but the 1.4. (Sorry)

jsherman999 · 07-21-2008, 12:31 PM

Originally Posted by fishy

In that case I might have to review my verdict; The da* @ f/5.6 at least matches the FA50 @ f/4.0 in crispness/sharpness. I might have been thrown off by bright light and hard contrast; my DA* suffers a lot from purple fringeing. Less light and it gets better.
One bad of mine: the FA is not the macro but the 1.4. (Sorry)

Ah. But the answer is still yes, the FA 50 1.4 at f/4 is sharper than pretty much any zoom you can buy, including the DA* 50-135.

If your 16-50 at f/5.6 matches the FA 50 at f/4, then I'd say you have a very good copy based on that alone.

You could test for centering defects, FF/BF in low tungsten light (tricky for almost any lens,) but really you should get out and take a whole bunch of real-world shots and see how much it pleases you.

fishy · 07-21-2008, 12:56 PM

Originally Posted by jsherman999

You could test for centering defects, FF/BF in low tungsten light (tricky for almost any lens,) but really you should get out and take a whole bunch of real-world shots and see how much it pleases you.

Thanks a lot for that jsherman. Maybe my expectations were just too high..
Dont want to be a measurbator (as demonstrated by limited skills) but unforunately I have very little time to see if the lens is good enough. I'll be leaving for East Timor shortly for an unknown time, so returning it from there would be ... tricky at best.

I will let it rest from here. Sorry if I abused this thread!

suro · 07-23-2008, 10:52 PM

I bought my Pentax 16-50* /2.8 lens recently a few days in Ekaterinburg (Russia). Number is: 9024487. By my personal opinion - is good lens. Few samples at f2.8:

Newspaper 100% crop:

My kitty (resize and 100% crop):

Flowers (resize):

Old newspaper (full size 10Mb JPEG):

http://ifolder.ru/7444451

P.S. Simple soft border - it's normal for must lens (and fix focal lens too).

leadbelly · 07-23-2008, 11:35 PM

i was about to buy a 16-50 awhile ago, but thought about asking here first... what should i look out for in the store? obviously, if it focuses sharp, BF/FF issues and what else? i'll be purchasing the lens tomorrow morning, just want to see what you guys would suggest on how to test..

suro · 07-24-2008, 12:02 AM

Originally Posted by leadbelly

i was about to buy a 16-50 awhile ago, but thought about asking here first... what should i look out for in the store? obviously, if it focuses sharp, BF/FF issues and what else? i'll be purchasing the lens tomorrow morning, just want to see what you guys would suggest on how to test..

You must check:

1. Manual focus work.
2. Back and front focus (take the foto of plain text on the f2.8 by 45 degrees).
3. Sharp at f2.8 (take the photo of newspaper). Border of photo may by simple soft - it's normal for crop lens.
4. Auto focus work.