[cputeq]

You will get as many lemons from Sigma and Tamron as you will get from any other lowprice brand, especially at the pricelevel of massproduced consumer cameras/lenses.

I disagree with this, to a point.

Yes, all manufacturers (excluding the extreme high end) are going to have their lemon lenses.

The problem is, we're not talking about a "lowprice brand", we're talking about a flagship Pentax DA* lens with enough internet anecdotal evidence to cause concern.

The simple fact there exists an entire thread dedicated to only this lens and various serial numbers and whether they're good/bad indicates something is wrong.


Normally, I wouldn't be too concerned, except that I really, really want this lens over any other variant.

It's weather sealed, SDM, and of course excellent Pentax optics when it works. Pentax's only other modern lens that even comes close (that I know of) is the 16-45mm f/4. I want f/2.8, not f/4, I want weather sealing, and I want SDM, I want 5 more mm, and I'm willing to pay 2x the price.


--------

The fact that after more than one year a flagship, top-of-the-Pentax-line lens is experiencing some major QC issues is the prime definition of "disappointing".

I'll probably end up getting the lens anyway, as I really want it, but if I end up having to send it to Pentax for 2 months or make 3 returns to Amazon before I get a "good" copy I'm going to be one mad S.O.B.

And for the love of god, don't trust all the alarms on internetforums. 99% of the people that are posting "OH NO MY LENS IS DEAD!" threads, would not know a bad from a good lense if they were born with one in their behind.

Yes, I do agree one should take internet gripes and complaints with a huge grain of salt. But claiming 99% of the posters proclaiming problems don't know what they're talking about is highly presumptuous.

[lithos]

Unless there's a surfeit of dodgy brickies in your area or you have walleye syndrome, by jeez, by jingo, by crikey, that's horrible.

Thank's for giving a pic, as I've been wondering what some of these 16-50mm problems look like. Even if it was centred, it's still an alarming amount of barrel distortion. Not as bad as my Sigma 18-200, but that lens ain't worth a grand either.

I really don't think it'd be wise for Pentax to ignore this any longer. There needs to be some sort of widespread recall/buyback scheme implemented, methinks.

[Zewrak]

I disagree with this, to a point.

Yes, all manufacturers (excluding the extreme high end) are going to have their lemon lenses.

The problem is, we're not talking about a "lowprice brand", we're talking about a flagship Pentax DA* lens with enough internet anecdotal evidence to cause concern.

The simple fact there exists an entire thread dedicated to only this lens and various serial numbers and whether they're good/bad indicates something is wrong.
[/b]

I consider the 16-50 a lowprice, massproduced lens. It costs like 1000$? And how many units are sold? 10k? 50k? 100k? 500k?

At 1000$ there is no room for QA in the budget. If the consumers said, hey, give us a 100% QA, does not matter if it costs us another 4000$ per unit. I am sure that every lens that comes from factory will be excellent.

Alot of the reports of good/bad copies seem to be B/F-Focus. That doesnt mean there is anything wrong with the lens itself, it could also be the camera. Or the cooperation between them.

Also note that it is a zoom and autofocus lens. The more gadgets, the more errors. Sigma has the same problem, I got a few lemons from them, with lenses that cost about the same as the Pentax ones.

If you want quality lenses, get a prime from Carl Zeiss, Im certain that you will get more QA, more quality and be more statisfied.

[b]
Yes, I do agree one should take internet gripes and complaints with a huge grain of salt. But claiming 99% of the posters proclaiming problems don't know what they're talking about is highly presumptuous.

Also remember that its always those that have problems that you will read posts from. Those that are happy will not be posting threads in the same extent, heck, they might even be outside taking photograps with their good lenses .

[Zewrak]

I really don't think it'd be wise for Pentax to ignore this any longer. There needs to be some sort of widespread recall/buyback scheme implemented, methinks.

Im sure its cheaper for them to get lenses back for fixing then have a proper QA.

[PentaxScott]

Assuming that the lens is perpendicular to the wall when the photo was taken I would agree that there is a descentering issue here. The right side of the shot is HORRIBLY soft, much more than a 16-50 should be. In fact, by my judgement (for what its worth) looking at the original full size image, the left edge appears to even be sharper than the center of the frame!

My suggestions would be to conduct a test with the camera on a tripod, perpendicular to the brick wall. Make sure to turn the SR *OFF* (this will affect the shots) and then use the 3 timed/mirror lock up feature to take the shot. If the results are the same...I would call Pentax for service.

[PentaxPoke]

Yes my camera was perpendicular to the wall. I am not a complete idiot! I took alot of shots this way at several zoom levels and apertures. Also, other shots of landscapes are the same way.

Consider this: that shot was at 16mm, f3.5 and I was 10 ft from the wall. So in terms of the depth of field, the near limit of focus is about 5.4 ft, and the far limit is 64.2 ft for a total DOF of about 58 ft. I don't think it is not being perpendicular to the wall! Also, the shutter was 1/500 and SR was on, so this wasn't a shake issue, and I don't think I need to redo it with a tripod.

[Wheatfield]

I disagree with this, to a point.

Yes, all manufacturers (excluding the extreme high end) are going to have their lemon lenses.

The problem is, we're not talking about a "lowprice brand", we're talking about a flagship Pentax DA* lens with enough internet anecdotal evidence to cause concern.

Lens manufacturers don't do continuous manufacturing of optics. Rather, they gear up for a particular lens and run a batch, then they gear up for another lens and run a batch, etc. The 16-50 definitely had a QC problem with early run(s), which is why there are so many complaints from far and wide.
There is no guarantee that a lens bought today wasn't from a first production run, since there is no way of knowing when the lens was actually built. Were I in the market for a 16-50, I would be buying from a local store so that I could put the lens on a camera and test it prior to handing my credit card across the counter rather than risking the irritation of buying a dud via mail order.

[PentaxPoke]

I would be buying from a local store so that I could put the lens on a camera and test it prior to handing my credit card across the counter rather than risking the irritation of buying a dud via mail order.

That is fine for those of you that have Pentax gear in a local store. A good number of us don't have that luxury. It would cost me alot more to go drive a couple hundred miles to find a store with that lens and test it out only to find it is a dud.

Good thing Amazon has a great return policy. I clicked a couple of links, and the refund is done. They even sent me to a link where I could print the shipping label, and UPS will pick it up for me. I'm not mad at the "mail order," I'm mad at Pentax for this continuing problem that hasn't been addressed yet. Maybe it has been at the factory, but the bad inventory is obviously still out there.

[Wheatfield]

That is fine for those of you that have Pentax gear in a local store. A good number of us don't have that luxury. It would cost me alot more to go drive a couple hundred miles to find a store with that lens and test it out only to find it is a dud.

Good thing Amazon has a great return policy. I clicked a couple of links, and the refund is done. They even sent me to a link where I could print the shipping label, and UPS will pick it up for me. I'm not mad at the "mail order," I'm mad at Pentax for this continuing problem that hasn't been addressed yet. Maybe it has been at the factory, but the bad inventory is obviously still out there.

I think the only way Pentax can handle it is to repair or replace defective lenses. I'ts not like as if 100% of them are faulty.
Now that they know they have a problem, I would expect any future production runs won't be problematic.
Pentax does seem to be having lots of QC issues these days though.
It's unfortunate that mail order purchasers are put out, but the marketplace went mail order at the expense of real stores long ago, and Pentax can't be held liable for that either.
FWIW, I know of a couple of dozen or so happy 16-50 owners whose lenses are good. The pre release one I tested was superb.

[flyer]

If he were not perpendicular, Both sides would be fuzzy because neither of them would be the same distance as the center of the image.

Not exactly. Since depth of field extend farther away from the lens than it does toward the lens, you can still have the end that is closer to you out of focus and everything else in "focus".

[selar]

My experience with the DA*16-50 has turned into a saga.

I bought the lens in December. I was generally dissatisfied with the lens and early March I took some test shots and posted them here to seek an opinion from other forum members. I got conflicting opinions, therefore decided to go by my own and returned the lens for repair under international warranty to CR Kennedy (Australian Pentax distributor). They kept the lens for 3 weeks at the end of which they returned the lens as having no fault.

Then I took pictures of the same scene with kit lens at 18mm f3.5 and with DA* at 18mm f4 and stitched and printed halves of the same shot together at A4 size. It was very clear to see that the kit lens was much sharper. I sent the DA* back for repair again with the print. This time CRK replaced the lens with a new one, that was faulty as well. I took the lens back to CRK, a technician tested the lens on a K20D and a K100D, and got unsharp pictures. He then tried another new copy from stock, with the same results. CRK said it appeared that the whole batch was faulty and they were returning the lot. As they didn't have a lens to replace they suggested I return the lens for a refund to the Singapore store I bought it from. I said I didn't fancy my chances of that happening, also I really would like a good copy of the lens as there is no other weather sealed SDM zoom in it focal range, so could they please send the lens to Japan to get it repaired, which they did last week. No idea now when it will be fixed, or whether it will be fixed at all, seven months after buying this lens for about $1000 US.

Apart from the first time, when they returned the lens unrepaired, I think CRK are honouring the international warranty. Many thanks to Peter Macoun of CRK who has been very helpful with testing the lenses.

However, Pentax is producing substandard lenses in the DA* range, not just the DA* 16-50 but also the 50-135 which has lots of flare. Whatever examples I have seen posted of the DA* 200 and DA* 300 have failed to impress as well. These have lots of purple fringing which one would expect not to have in a designed for digital lens which is also top of the range. The * marking has ceased to have any meaning with the discontinuation of the FA* and F*series. SDM and weather sealing are great things to have, but if it means poor IQ, substandard build quality and plastic barrels, is it really worth dropping large sums of money on these lenses?

[morfic]

Not exactly. Since depth of field extend farther away from the lens than it does toward the lens, you can still have the end that is closer to you out of focus and everything else in "focus".

I'd like to second that, looking at the top it even looks like it is in focus on left, acceptably in focus in center and soft on right, something you would see from a lens that is not perpendicular.
If you look on the left from top to bottom, the top is sharper than the bottom, if you look on bottom from left to right, you can see how the center is already softer than it was on the top.
Just saying it could very well he held it tilted and swung.

I'm not saying i doubt the OP is a master hand holder, but the problem with testing new equipment is, you will find what you look for in 90% of cases.

How do real shots look like? If it is decentered, it will be visible in more than synthetic situations like a hand held brickwall shot.

I know lenses go to Pentax, then the body goes and back comes happyness, that's the same for other manufacturers. What i wonder is how many percent of bad lenses are found due to forums (As in induced in our minds)

All i know is that not knowing how much is hysteria and how much is real has me wonder if i should dare order one or not now
The reason to buy name brand instead of Sigma and Tamron would be to avoid sample variation headaches. (ok, i'm a sucker for SDM too, and Sigma won't make the HSM for anything but Nikon (grrrr))

I guess in short: Don't test lenses synthetically until after you find problems in real shots, and lets see how the reputation goes then. (And i don't suggest you take it out of the box on a paid gig either, just not brick walls after the unboxing )

Thanks for reading all the way to here,

Daniel

[PentaxPoke]

Daniel,

I posted twice that I saw these defects in landscape and other shots. Did you read my posts? The only reason I am shooting brick walls is because I had so many shots soft on the right side, and I wanted a consistent background. The bricks only confirmed the problem at every aperture and every focal length.

Again I summarize: the pictures from my DA* were soft on the right side on almost all my shots, not just the bricks. I was not looking for a problem. It found me.

[morfic]

I think the DoF number i also missed is more convincing that anything else.
I guess i have a thing against test shots (even if i drive myself crazy with them)
I guess it's catch 22, had you chosen a landscape shot to show it's soft on the side, people had claimed other effects probably and demanded a brickwall shot.

It was not meant as a personal attack, more a general rant, maybe sometimes my words don't properly convey my thoughts, the "I guess in short: ...." part was more for those who ordered a 16-50 and then hit up the thread

And to clarify, yes, i did skip your post where you mention it's on other shots too, apologies.

Daniel

[PentaxPoke]

Sorry if I was short. I am just still mad about this problem that I have been reading about for months and months. I thought it would be solved by now. I have always been a Pentax cheerleader, but they have made a fool of me on this one...