DA* 16-50mm Serial Number Database.

[jsherman999]

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It's worth it, people!!

Some test shots taken the last couple days from a good copy:

Picasa Web Albums - Jay - DA_16_50



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[wtlwdwgn]

I have SN 9015311. Although it was back focusing a little, between 10 and 40mm, I was getting really great images with it. I did send it , the 50-135, and the K10D to Pentax USA for service and adjustment. I got it all back within two weeks all nice and shiny and clean. It no longer back focuses and the images are just as good as before.

[dbh]

9012359, good, bought locally

To the OP do you have a summary table of your data so far?
--
dbh

[applejax]

So, while there's not nearly enough data to be statically significant as was already mentioned, there exists the possiblity for a couple of trends developing.

The four earliest recorded serial numbers to this point are "good". This is the only time in our limited sample that we have a trend of four "good" numbers in a row.

While there is no direct correlation between serial numbers and dates purchased, if we assume that observation #1 is true, then the "bad" numbers start around the turn of the year.

The last two entries, the two highest serial numbers, are listed as "good". While this isn't nearly enough to draw any conclusions, we may have a starting line for "good" lenses.

A "bad" copy with a lower serial number than those mentioned in #4 was received on March 17th. Regardless of assumptions on #3, inventory has not turned over with shipments of "good" lenses as of this date.

Serial Status Place and Date
9011133 good used from a forum member
9012269 good Pentax retailer in Helsinkiin October
9012359 good bought locally
9012509 good
9012541 bad Amazon, beginning of January
9013067 good
9013251 good
9013254 bad
9014888 good
9015311 bad
9015921 bad hometown store
9016333 bad
9017115 good
9017292 bad B&H
9017525 bad So it's a bad copy on K10D, but a good one on K20D
9017549 good Digit-Photo in December
9018018 bad Amazon
9018137 bad Amazon03-17-2008
9018380 bad B&H
9019612 good
9021117 good

[dbh]

Too bad we so far cannot decode from the S/N such things as a change in factory, which batch of glass was used, day of the week, or disgruntled QC inspector etc.
But presumably Pentax has all of that info and more and, unless they don't care, at some point the bad ones should disappear completely.
In other words from about 9020000 on should be dud-free.
--
dbh - the optimist thinks thinks things have never been better. the pessimist fears the optimist is correct.

[dietcokefiend]

9017856 decent

Focusing seems about right, only complaints is some CA and the SDM focusing tends to chirp as it moves in and out of focus. Anyone care to comment on what their SDM motor sounds like?

[bymy141]

Originally Posted by dietcokefiend

9017856 decent

Focusing seems about right, only complaints is some CA and the SDM focusing tends to chirp as it moves in and out of focus. Anyone care to comment on what their SDM motor sounds like?

Mine is completely silent.

- Bert

[dietcokefiend]

Yea mine was too, and still is for the first one or 2 focuses after letting it sit. If you start focusing on multiple points close or far away, the thing has a bit of a faint chirp when it reaches the target, then a bit of a small click as it releases the clutch mechanism. Moving back and forth it just has a mild whirr sound to it, just like my DA* 200mm.

The 200 also has the click as the clutches engage/disengage, but not of the chirp. We did have another older DA* model in the office that had a faint chipmonk sound, but it was much much older. Perhaps it is just something that shows up as it breaks in and loosens up?

Focusing otherwise is spot on at both 16 and 50mm.

[rvannatta]

9012114 here.--- Although I have mumbled about it, I cannot demonstrate obvious bad behavior. I'm inclined to rate it asa good as there is no obvious front or back focus. What I see particularly with my early one added to the list is thte the early numbers seem to be pretty good---or else all the bad ones have been long ago returned and the Serial # forgotten.

[Polaski]

I just bought one of these. It works. I have no interest in the serial number. Come on, fellas, get on with it.

[Tbear]

Bad: 9016761, 9013124

Good: 9011024

[christinelandon]

This one's on my LBA list, so I'm interested in the resolution of the problems reported by some Forum members. Please, to make this thread useful, can you post where you purchased the lens along with its S/N? When this reporting is hit or miss, we can't resolve the allegation that some vendors are reselling returned duds. Thanks, everyone!

[thear]

9019346 from Willoughby's appears to be good. I tested the lens with the focus test chart, newspaper, and flowers.

[aegisphan]

9018546 from Amazon is an excellent copy. I bought it on Wednesday, March 26th. And this is my first try too . By the way, I use it on my K20D so I don't know about its performance on the K10D yet.

[frostugh]

I bought mine from Willoughby's Camera within the last month. The serial number is 9021232 and the edges are super sharp wide open at 16mm. Given the history with this lens, I've been looking for trouble with mine, but I haven't found anything yet.