DA* 16-50mm Serial Number Database. - Page 13

bigben91682 · 08-19-2008, 03:29 PM

After 2 duds I took a few months off, and just ordered my third copy of this lens (hopefully it's the "charm" as they say). Somebody bought one of the ones I returned as refurbished and it was fixed by then....

Luckily it's pretty risk free here in the states. Amazon is great for returns, they even pay return shipping, so while a bit of a hassle - a bad copy isn't that big of a deal to me. At this point I'm just going to keep trying until I find a keeper. My lastest attempt shipped today, so here's hoping!

Sleepy · 08-19-2008, 07:28 PM

I got mine today and the SDM wasn't working.
S/N: 9018887

nicedog · 08-19-2008, 08:05 PM

Is your camera k10d? Did u upgrade the firmware?

little laker · 08-19-2008, 08:05 PM

Sleepy,
Considering what lens it is your probably right about the SDM being faulty.

However I'd try cleaning the contacts first, and hope for the best.

nicedog · 08-19-2008, 08:09 PM

Got mine not too long ago, here's some test shots.
tamaracky - Photobucket - Video and Image Hosting

What do you guys think?

Sleepy · 08-19-2008, 10:55 PM

nicedog and little_laker, thanks for your replies.
My camera is K10D and my 50-135mm works fine on it.
The contacts on 16-50mm are clean.

Besides, the description of the item said "New in the box" but I found finger prints on the lens body as well as rear lens cap and the rear lens is not clean. Plus, the manual is missing.

Therefore, I've returned the lens and hopefully I could get the refund right after the seller receives it.

wiyum · 08-20-2008, 04:23 AM

Originally Posted by nicedog

What do you guys think?

I think I haven't seen nearly enough to judge. You need to test at at least 5 different focal lengths, 3 different iris settings, and as many focusing distances as you can. Mine exhibited doubling in the corners at wider apertures (but not stopped down) around 28mm (still apparent, but less so, at 35 and 20), and at most focusing distances (but not absolute close focus).

The point that I make here is that there could be a very real problem that could be highly undesirable (as I believed actual doubling to be), but unless you run a battery of tests, you may not find it. Set aside a couple of hours, find a large, text-rich, planar surface, and go to town. Hopefully you have a 2GB card or bigger.

Will

PentaxPoke · 08-20-2008, 02:06 PM

I agree with Will. Don't let happen what happened to me with my first DA16-50. I didn't notice the problem until later. Some people will tell you "don't worry about the lens, just go out and shoot pictures and enjoy etc., etc." The problem is that while you are taking pictures of objects that are in the center of the field of view, that lovely bokeh may be masking a serious problem. You won't notice it until you take a picture where your subjects are all in the same plane of view, like taking a picture of a group of people, or a beautiful landscape. This is why it is important to run tests when you first buy a lens. Test on subjects that are all in the same plane of view. That is why the ubiquitous "brick wall" is so popular.

nicedog · 08-20-2008, 05:09 PM

A picture taken at f/2.8 16mm, and let's say, it's soft on both sides. I keep telling myself, isn't that normal?
I checked some other lens reviews such as nikon 20-35mm f/2.8, it has the same problem too.
I mean, a brick wall picture with blurry image on both sides really means the lens is bad?

PentaxPoke · 08-20-2008, 11:07 PM

Originally Posted by nicedog

A picture taken at f/2.8 16mm, and let's say, it's soft on both sides. I keep telling myself, isn't that normal?
I checked some other lens reviews such as nikon 20-35mm f/2.8, it has the same problem too.
I mean, a brick wall picture with blurry image on both sides really means the lens is bad?

No, it is a question of how bad. Lenses are naturally softer near the edges. Decentering is easier to spot because the softness is asymmetrical. There are other types of defects though (and the DA*16-50 seems to have many of them). For example, in the latest example I posted here, the softness was symmetrical, but it was absolutely terrible. (In fact it if you believe laker, it made him dizzy

) Usually, the softness at the edges sharpens as aperture is reduced (higher f/stop). In my case, there was no improvement at any aperture or focal length. As I mentioned in the other thread, it was a bit like looking through the bottom of a Coke bottle.

Now my first lens wasn't as bad. I noticed the problem eventually when I realized all my pictures were softer on the right than the left. These examples are not me being picky. These two lenses I had were clearly worse than my 18-250 lens that costs about half as much.

I just got confirmation from B&H that my replacement lens just shipped. I'll let you know what new defect this one has.

wiyum · 08-21-2008, 01:48 AM

Originally Posted by nicedog

A picture taken at f/2.8 16mm, and let's say, it's soft on both sides. I keep telling myself, isn't that normal?
I checked some other lens reviews such as nikon 20-35mm f/2.8, it has the same problem too.
I mean, a brick wall picture with blurry image on both sides really means the lens is bad?

There is of course a question of how much softness is acceptable and normal, which is why I started a different thread trying to gauge what my expectations should be.

If you're anal and have access to a graphics program like Illustrator though, you can make a graphic and see that an image circle that JUST covers the full frame leaves the top center and bottom center well within the circle and the left center and right center reasonably within the circle. If you see extreme softness in those places,you may have a problem. Really, the corners are the only place where outright noticeable softness is normal, and even then, only at wide apertures.

I wasn't sure if the corner softness of my last sample was unacceptable or not, until I noticed doubling, which should never be happening.

With that, I'm about to test my replacement, which arrived today.

wiyum · 08-21-2008, 03:42 AM

...and it looks like I've got a keeper. BF/FF test resulted in best focus with zero adjustment in the k20d menu, and my dvd shelf test looked like it went fantastically. At times, I was amazed at the sharpness in the corners. I'm doing the newspaper test tomorrow to clear up one last thing (my shelf is vertically oriented, so my camera was vertically oriented, and as a result, the camera twisted a bit on the tripod plate, what with gravity and the weight of that lens), but most of the pictures revealed no flaw whatsoever.

And to all of the testing naysayers... yes, then I'm just going to go out and enjoy using the lens.

Serial number coming once I double check.

Will
who really misses the prep area at Clairmont Camera, where cameras use plates with two screws, and are placed on pedestals that are built in and perfectly aligned with the center of the self-illuminating test charts that are attached to a roller on the ceiling. No room for questions of exact perpendicularity there.

BTW: Spell check had no problem with "perpendicularity," which strikes me as a pleasant surprise.

bigben91682 · 08-21-2008, 04:39 PM

Just got my third copy...it's in the 903xxx series, so very new production run. Quick tests have me optomistic, I'll put it through its paces this weekend.

Imagination4 · 08-22-2008, 07:28 PM

#1 from Amazon - S/N 9027050 - BADly decentered. Sharpest area was NOT at the center, but about one third off center towards the left. Right was horrible.

#2 also from Amazon - S/N 9027536 - BAD - but not sure I'd say it was decentered. From 16mm to 20mm+ it behaved pretty much as I'd expect.

From 24mm up thru 50mm, the center remained very sharp and contrasty, and the left half of the frame behaved quite well. However, on the right side about 1/4 to 1/3 of the entire frame became unsharp and blurred to the point where the right 25% of the entire image looked less sharp than my 18-55mm AL II Kit lens. Whether coincidence or not, while I was taking the test photos with the 16-50mm I noticed that the center focus point was rotating about the center cross (that I was using as a central focus point) while I was zooming the range out from 16mm thru 50mm.

Amazon.com Customer Service sent me a polite e-mail stating that they would NOT exchange my second DA*16-50mm for a third one, but would issue me a refund once the lens has been returned to them. I wonder how many they've had returned to issue that statement - as their site still shows these in stock. All I wanted was a weather-proofed wide-to-standard/mild-tele zoom lens.

little laker · 08-22-2008, 08:12 PM

Originally Posted by bigben91682

Just got my third copy...it's in the 903xxx series, so very new production run. Quick tests have me optomistic, I'll put it through its paces this weekend.

Good luck with it Ben