[felixkh]

Got mine in March 09.
S/N: 9027247

[exodus]

9030621 bought from Amazon. After a week I found a mechanical problem of Aperture getting stock at F2.8.
The Lens was replaced with 9027821 by the Pentax Israel Service. So far the new Lens is good.
I would like to thank Ronny Sahar and Guy Ben-nun from the Pentax Israel Service for their excellent assistance.

[Horst-Helmut]

Now that I have taken 100+ shots in varying conditions during the weekend I have to say hot damn that's a piece of equipment! Bought it used and had a chance to quickly check the known qc issues before buying it.

Good copy
Sn 9019310

[mrdfred]

9022950 - from Amazon
Help me interpret my results. I shot 2 different targets @ f2.8 and 50mm. Both showed good focus in the center and serious drop off of sharpness on the right and moderate drop off of sharpness on the left. Additionally there was serious chromatic (sp), aborration with blue fringing on the left of a solid black line and yellow/gold fringing on the right of a solid black line. the same was moderately true on the left. I did not shoot at any other f-stops, only f2.8 and 50mm. My question is; should I determine how the lens performs at other f-stops? This seems bad enough for a lens of this price and advertised quality to warrent returning. Am I too picky?

[little laker]

mrdfred, There's no way anyone can judge your copy from just a description of what you see. So how about a picture or 2.
You may want to try the tests the others are using as well.

[mrdfred]

Attached is the test shots I took. I used a tripod, shutter release, made sure that the camera and target were on the same plane in all directions (level, target and camera back parallel), SR off, Spot meter and focus. The test shots were made at 10X the focal length, 500mm. The image I have included is a composit of the target, the left side enlarged, the center enlarged and the right side enlarged. The camera is a K10d. I have tested it for FF and BF and made adjustments using the debug menu. All of my lenses are focusing properly, including the DA* 16-50.

[sebberry]

Sounds like a lot of people are having to get one or two replacements before they find a good copy of this lens. Is this limited to the DA* 16-50 or are the other DA* lenses suffering from shoddy QC as well?

The amount of money that Pentax is spending on fixing and shipping these lenses from service center to service center must be eating away at their proffits. Why can't they get it right the first time? Stick it on a camera, take some test shots, repair if needed and then ship it to retailers?

[ironcorn]

Hi,
9030634
Bought from Amazon in Aug 2009. Used for one month, worked fine with my K20D. Then the autofocus started acting funny, working REALLY slow and now it basically quit all together. Getting ready to send it back to Pentax. Not happy.

[john mood]

SN 9028542. Received today from B&H and so far so good. Didn't know there was an issue.
Very sharp. Attached is pic of my Corgi shot at full zoom 50mm, f/11, 1/20, iso 100 raw with K-10D. Loaded into Aperature with no modifications.https://www.pentaxforums.com/forums/images/smilies/biggrin.gif

[mdsnexp]

My DA* 16-50mm, serial - 9030726 - is being sent in for repair, non-working SDM focusing mechanism.

Purchased from Amazon in May 2009.

When I received it, I mounted it on my K10D and used it on 'screw drive' for a day until I did the firmware upgrade to take advantage of SDM. Used it with SDM for 5 months - VERY happy with the resuts. It's a great lens!

Unfortunately, the SDM motor froze up 2 weeks ago - was moving slow......and then nothing.

Kit lens (18-55mm) with the screw drive works fine on my body, and I'll use it in the mean time.

This is my first warranty issue with my Pentax setup. Hopefully, I will be satisfied with their response.

[Buutopia]

9023033 - Bad. Ordered from Adorama. At F2.8, left fourth of image is soft across entire zoom range.

120176670 photo - buutopia photos at pbase.com

[openyourap]

SN9028167.

Out-resolves my (K20D)sensor from corner to corner across all F stops. CA control isn't as heavenly, but still a respectable couple of pixels in extreme contrast shots - easily fixed in PP. I haven't yet tested whether CA improves if I remove the filter.

[gabal]

Hi
I was quite happy with the lens except for the CA. I like to shot on the street so i find it big, heavy and the opposite of discreet which is bad when you want do take candid shot. Now i have a 15mm and 50mm to be less flashy, and keep my 16-50mm for family gatherings and the like.
The SDM just died recently. I had seen signs of hesitation when i was using it but attribute it to my lack of experience. But now it doesn't even do a sound. I have seen that it is a concern of a lot of users. I have read some people being upset that you can't use the screw system of Auto focus but what would be the point of an expensive lens if you get rid of one important aspect of it. So far with what i have read, Pentax never admitted any weakness in this system which is disappointing; i dont think it is a coincidence that we see so much dead SDM or not the kind of picture you would expect from a "pro" lens. Quality control or, in the case of SDM, lack of a long lasting driver. I liked it when my son's X box broke with the "circle of death" that Microsoft admit the problem, extended the warranty, took care of shipping both ways, got us a fixed system and gives us credit on the Xbox Live subscription that we lost in the time we didn't had the console. Twice ! That's class !
I know my warranty is expired but i made the purchase with a credit card that double the warranty so it should be fix without cost (hoping it wont be hell to deal with that) but for a working operation of how much time ? If it last just a year again then what : 2, 3 or 400$ to get it fix ? Should I, once it's fixed, resale it ?
So my serial no is : 9024121.
The popphot.com review :
Pentax Pentax DA* 16-50mm f/2.8 SDM AF - Lens Review from Experts at Popular Photography- Photo Tips
I like the last line : However, owners of the K10D and K20D -- and Pentax legacy DSLR shooters who plan to upgrade to newer bodies -- may want to invest in this new zoom for its silky new SDM-driven auto-focusing and its clearly superior, last-forever build.
I hope yours last forever !

[esman7]

Bought from London Drugs today.
9010746

Here are some test shots at 16mm of the vignetting everyone was talking about. Not that bad past 16mm, but @ 16mm check out the vignetting (top corners) which is most pronounced at f2.8. All at ISO 100. Pics at f2.8, 4, 5.6, 8, 11

Should I be returning this or is this expected? It doesn't really come up too much at 24mm, but it comes back at 50mm! Check the 50mm shots in my next post.

[esman7]

...and these are the ones at 50mm FL.

Pics at f2.8, 4, 5.6, 8, 11