[Tbear]

QC issue is real, I have gone through it too with two DA16-45/4 (still not perfect, but usable). However, I agree that Ted should at least do some real photography with the lens instead of rely totally on the newspaper test. My FA43 does absolutely horrible on the newspaper test but fine for landscape.

Let me ask you Alan. If you paid 8 times as much for a * lens compared to your kit, would you be happy if you found that your * lens demonstrated very obvious decreased sharpness compared to your kit lens on identical focal length/aperture settings? Would you find that remotely acceptable? I must be a pixel peeper because I feel like the DA* 16-50 should be able to outperform the kit lens on a newspaper test. I guess Klaus over at Photozone must have been pixel peeping when he reviewed the DA* 16-50 and found obvious centering defects so severe, he pulled the review.

[Tom Lusk]

There are other members here that have given up on this lens after getting a dud to replace their initial dud. At least one went through 3 duds before giving up on this lens altogether.

Another thing to keep in mind is that there was a very informative post on DPR where a poster actually disassembled his copy and was able to determine that the combination of poor (rough) finishing on the interior of the lens barrel and some plastic parts that come in contact with the roughness while zooming result in the lens failing after being in use for a relatively short period of time. He was able to have some custom replacement parts made at his place of employment (fabricating the failed parts out of some new better quality material). Problem solved!

So- even if the lens does perform properly right out of the box, the potential is there for early failure.

Tbear - unless you accept the replacement lens without question, regardless what your test shows, be prepared to be labelled a whiner. It has already been determined, somehow, that your testing methods are faulty.

[Tbear]

There are other members here that have given up on this lens after getting a dud to replace their initial dud. At least one went through 3 duds before giving up on this lens altogether.

Another thing to keep in mind is that there was a very informative post on DPR where a poster actually disassembled his copy and was able to determine that the combination of poor (rough) finishing on the interior of the lens barrel and some plastic parts that come in contact with the roughness while zooming result in the lens failing after being in use for a relatively short period of time. He was able to have some custom replacement parts made at his place of employment (fabricating the failed parts out of some new better quality material). Problem solved!

So- even if the lens does perform properly right out of the box, the potential is there for early failure.

Tbear - unless you accept the replacement lens without question, regardless what your test shows, be prepared to be labelled a whiner. It has already been determined, somehow, that your testing methods are faulty.

Thanks, Tom. If demanding more from my DA* 16-50mm than my kit lens makes me a whiner, then so be it. Interesting that you mention the poor interior construction/design that one user found on disassembly. There is a recent post here that talks about the early demise of his SDM on his DA* 50-135mm. I wonder if this could be related to that?

Ted

[little laker]

Another thing to keep in mind is that there was a very informative post on DPR where a poster actually disassembled his copy and was able to determine that the combination of poor (rough) finishing on the interior of the lens barrel and some plastic parts that come in contact with the roughness while zooming result in the lens failing after being in use for a relatively short period of time. He was able to have some custom replacement parts made at his place of employment (fabricating the failed parts out of some new better quality material). Problem solved!

So- even if the lens does perform properly right out of the box, the potential is there for early failure.

Tom, I'm wondering if you happened to bookmark that page.
It sounds like an interesting read.

[blende8]

The post is here:
Re: Just tested my new DA* 16-50 and boy does it stink: Pentax SLR Talk Forum: Digital Photography Review

Extract:

E.g. my DA* 50-135 (which is a replacement from the 2nd batch, the 1st was a absolut lemon!) produced excellent results for the first 1000 shots and starts to deteriorate than continously. Because I was thick waiting another couple of month for a replacement I took it apart and figured out that the plastic pinch rollers which control the movement of focussing-lens inside the lens barrel are already worn out by 6/100mm. The resulting "play" of the otherwise backlash free focussing mechanism was absolutly intolerable, generating random focussing results.

I replaced the worn out "plastic" pinch rollers by new one´s which were made from higher grade plastics with tighter tolerances and smoothed the roller guidance inside the lens barrel. After that all focussing problems were gone! Even in "cold" environment (-5°C) the SDM-motor focusses properly (what wasn´t the case before).

[little laker]

The post is here:
Re: Just tested my new DA* 16-50 and boy does it stink: Pentax SLR Talk Forum: Digital Photography Review

Extract:

Thanks Wieland,

Very interesting,

If someone can do it on their on it shouldn't take Pentax long to fix any problems.

[Tbear]

Thanks Wieland,

Very interesting,

If someone can do it on their on it shouldn't take Pentax long to fix any problems.

Let us hope so, Stu, let us hope so

Ted

[jgredline]

Let me ask you Alan. If you paid 8 times as much for a * lens compared to your kit, would you be happy if you found that your * lens demonstrated very obvious decreased sharpness compared to your kit lens on identical focal length/aperture settings? Would you find that remotely acceptable? I must be a pixel peeper because I feel like the DA* 16-50 should be able to outperform the kit lens on a newspaper test. I guess Klaus over at Photozone must have been pixel peeping when he reviewed the DA* 16-50 and found obvious centering defects so severe, he pulled the review.

Yes!!! This is exactly my point. I even put up examples of photos with my cheapo Kit lens and my wazzoo DA*16-50 lens and would have even been happy after a while with equal quality...Now that I have a good one (although I have not done a newspaper test) I feel it is no better than my Tamron or sigma lenses...Now the DA*50-135 is rock on my best lens...That is an amazing lens which brings up the question. How can one be so good and one be so bad?

[Tom Lusk]

Thanks Wieland,

Very interesting,

If someone can do it on their on it shouldn't take Pentax long to fix any problems.

Maybe not.

The first step is to admit there is a problem.

The next step should be to recall all these lenses (like that is going to happen!).

The final step would be to change suppliers of the problem parts or lop off a few heads if the problem is internal.

[jmdeegan]

While I know people have gotten good copies right off the bat, or after a return or two, the publicized issues were one reason I skipped this for now, and instead went for the 16-45 which has much less of a bad rep.

Part of it was my fear of getting a bad copy and unwillingness to go through the issues, another was admittedly my concern surrounding my lower level of experience, that it would not be as obvious to me that I got the dud.

I went for the 50-135 instead, and I love that lens. And I am pretty content with the 16-45.

But as someone pointed out, those who hate something do tend to be more vocal than those who have good experiences. So I didn't base my decision strictly on the abundance of bad news

Maybe not.

The first step is to admit there is a problem.

The next step should be to recall all these lenses (like that is going to happen!).

The final step would be to change suppliers of the problem parts or lop off a few heads if the problem is internal.

[Lowell Goudge]

in all of this, I think there is a lesson.

If you are ever thinking about a full refund, go through the store. As th eOP indicated, they will not accept a substituted product for the one they sold (even if substituted by the OEM)

Also, if there is ever a problem, the store has more financial clout with any supplier than John Q Public.

Once exchanged by the manufacturer, you have essentially accepted the entire terms and conditions of thier warranty and you are locked into it.

I have only ever returned anything once, my Sigma 70-200F2.8 origonally arrived with the bayonette mount for the lens hood 30 degrees off horizontal. Clearly a goof at the factory. The store exchanged it no issue, but only after confirming I had not filled out the warranty documentation. I never do.

[Rico]

A. I wanted Pentax to be aware that they had a problem with this lens. So I sent it directly to the source. Terrible of me to do that. I should be shot.

B. The same reason they have sent some people 3 or 4 bad copies of the lens: The QC on this lens stinks. The second lens they sent me did not perform as well as my kit lens, yes, tested on a newspaper. If it makes you feel better to keep on saying this was due to flawed testing, be my guest. All that I can say is, if you were with me for every step of the test right up to the point of comparing the images side by side on Lightroom, you would be left with no doubts that there were serious centering defects. Were you aware that Photozone tested one of these lenses and found centering defects that were so bad, they pulled the review in the interests of fairness to pentax? Oh, yeah, I guess Klaus must have used flawed testing also.

Now Tbear A. Unless the type of shooting you are suggesting means using your DA*16-50 to take some self portraits than we are not even close to being on the same page.

B. Why on earth would Pentax keep sending people 3 and 4 bad copies of the same lens? At some point one has to ask if the "testing" those people are doing is not what is flawed. If you keep repeating the same flawed test you get the same flawed results each time.

As for Photozone like Reviews on DPR I personally take with a grain of salt. Those sites seem like ordinary people with websites. What scientific standards are they running by? Are they good resources for the general picture certainly do they have the definitive answers not likely.

As I said when you first posted your dilemma good luck in resolving your predicament.

[Tbear]

Now Tbear A. Unless the type of shooting you are suggesting means using your DA*16-50 to take some self portraits than we are not even close to being on the same page.

B. Why on earth would Pentax keep sending people 3 and 4 bad copies of the same lens? At some point one has to ask if the "testing" those people are doing is not what is flawed. If you keep repeating the same flawed test you get the same flawed results each time.

As for Photozone like Reviews on DPR I personally take with a grain of salt. Those sites seem like ordinary people with websites. What scientific standards are they running by? Are they good resources for the general picture certainly do they have the definitive answers not likely.

As I said when you first posted your dilemma good luck in resolving your predicament.

Rico, we may not agree on the validity of the testing, but I thank you for your kind sentiments. I'm going to need all the luck I can get.

[Rico]

Tbear if you can claim the rebate on the 31 the $150 exchange might not be so bad. The pricing looks like they are going off of Pentax USA online store. They have the DA*16-50 for $915 and the 31 for $1,155.

[Tbear]

Tbear if you can claim the rebate on the 31 the $150 exchange might not be so bad. The pricing looks like they are going off of Pentax USA online store. They have the DA*16-50 for $915 and the 31 for $1,155.

Thanks Rico, I did still consider this even though the difference at B+H is $40. However, I really would much prefer a great lens that: A) gives me flexibility in focal length from moderate wide angle to portrait. B) has weather-sealing C) has HSM and D) clearly outperforms my kit lens optically. I am still somewhat hopeful that Pentax will eventually send me just such a lens in the form of a fully-functional DA* 16-50. The 31mm, as awesome as it is, is just not worth $150 more to me than a well-made DA* 16-50.

However, I do appreciate you providing the helpful information.

Ted