DA* 16-50mm Serial Number Database.

[bymy141]

I have 9013251 and its a good copy.

- Bert

[ranamar]

9012509, so far so good.

[song_hm]

9016333 - bad copy, returned

[frank]

Just got mine yesterday. On K10D it is a really ugly one especially at the wide end But on K20D it looks pretty okay even w/o any focusing adjustment (hard to do AF adjustment for a zoom lens anyway).

So it's a bad copy on K10D, but a good one on K20D.

BTW, its sn: 9017525.

[sashae]

9012541, good.

[Timbuctoo]

I did some basic stats. So far there are 16 posts on the 16-50mm lens. 9 have been good versions and 7 have been bad. That works out to being;

Good = 56.25%
Bad = 43.75%

So far that's not really good enough for a lense worth the amount it's selling for even if the lense has been specifically calibrated to function as specified on the K20D because most of us still use the K10D.

I'd really like to get both the SDM lenses but as far as this lense is concerned I'll wait till the good verses bad ratio looks a bit better. I might give it a crack when the % of good lenses reaches 70%. Keep posting because it helps to get accurate results.

Tim H

[frank]

Originally Posted by Timbuctoo

I did some basic stats. So far there are 16 posts on the 16-50mm lens. 9 have been good versions and 7 have been bad. That works out to being;

Good = 56.25%
Bad = 43.75%

So far that's not really good enough for a lense worth the amount it's selling for even if the lense has been specifically calibrated to function as specified on the K20D because most of us still use the K10D.

I'd really like to get both the SDM lenses but as far as this lense is concerned I'll wait till the good verses bad ratio looks a bit better. I might give it a crack when the % of good lenses reaches 70%. Keep posting because it helps to get accurate results.

Tim H

The DA*50-135 has been widely reported as a good lens. I tested three of them, all are pretty good. My newly purchased one is good on both K10D and K20D.

As to the DA16-50, the majority problem is the BF problem at the wide end on K10D camera, but mine works fine on the new K20D camera (while pretty bad on K10D, probably the worst among the 3 I've used). I've seen similar report (by Wim from Netherlands) on DPR. But seems some guys have problem focusing on the infinity w/ the DA1650 and K20D combo too ...

[desame.one]

Serial Number: 9014888
My replacement copy is a champ! I tested using vector-based picnic stripe patterns printed at 600dpi on a HP LaserJet 4350n. All exposures were as excellent as one can hope for in a DA* zoom lens.

Focal lengths tested: 16mm, 20mm, 28mm, 35mm, 50mm
Apertures tested: f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22

Cheers!

Originally Posted by desame.one

Serial Number: 9013254
Of all the bad images related to the DA* 16-50 that I have seen on this forum, I think I had the worst copy of the lens. At all focal lengths and apertures, my images were blurry (double images) with the exception of the center area being very clean and sharp.

Replacement was due for delivery yesterday, but my wife didn't hear UPS ringing our doorbell. I'll report back after Monday with the replacement's serial number and test results.

[Kahless]

Good = 56.25%
Bad = 43.75%

Of course compiling that stat from this thread is not a true reflection of the quality of this lens, and is probably a form of selection bias.
People are more likely to search out a possible problem with their lens (pentax forums would be one of the first places found), and then post here.
Lots of people with a good copy of this lens will never even bother visiting here, even fewer still would bother to register, and fewer still to post come post and say that their lens was good, but never come back here again.

The only one that would have any accurate numbers on this is Pentax, and chances are slim they would ever release that info.

The idea behind this thread is a decent idea though, just to see if there is any correlation between model numbers and bad lenses.

[applejax]

It would be beneficial to include date of purchase and where purchased from.

[Buddha Jones]

Probably not as beneficial to find a manufacture date...

[huqedato]

Mine is 9017549, bought in France from Digit-Photo in December.
No problems detected so far, works perfectly. Good copy.

[bigben91682]

Recieved my second copy today from Amazon. Absolute rubbish, worst than the first.

SN 9018137

(only about 120 ahead of my last bad one which was post #3 in this thread)

I give up on this lens for now...it's going back and I'm going to see if I can find a 16-45 locally because I need it for this weekend...or just take the kit with me...

[Steven Yampolsky]

Originally Posted by Buddha Jones

Please help out, if you have a DA* 16-50mm please post your SN# here and wether it is a good or a bad copy and if it's a bad copy where you got it from. This will help to keep count of bad vs. good and perhaps build a corrolation with the serial numbers as well.

Any chance someone can post test procedure as well? Common test procedure will only make these results more consistent.

[SpecialK]

I did some basic stats. So far there are 16 posts on the 16-50mm lens. 9 have been good versions and 7 have been bad. That works out to being;

Good = 56.25%
Bad = 43.75%

So far that's not really good enough for a lense worth the amount it's selling for even if the lense has been specifically calibrated to function as specified on the K20D because most of us still use the K10D.

I'd really like to get both the SDM lenses but as far as this lense is concerned I'll wait till the good verses bad ratio looks a bit better. I might give it a crack when the % of good lenses reaches 70%. Keep posting because it helps to get accurate results.

Tim H

16 is a statistically insignificant sample. And, "good" or "bad" is hardly analytical and may only be based on expectations or...?

I do agree it does not look promising at this point. Luckily, I'm not looking to get this lens, but the 50-135 has some potential.