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05-04-2013, 06:49 AM   #1
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Bought a decentered 16-45...what to do :/

I bought a 2nd hand 16-45. At first since I had to swap mount rings from my k-5 to my k-7, I assumed that there was something wrong with my mount or that it was not parallel to the sensor plane. I then tried a bunch of other lenses and none exhibited the sharpness issues on the right edge that this 16-45 is showing. I loosened the mount very slightly and tried taking some pictures with some pressure one either side to see if shimming would have any effect and it did nothing to improve quality. When I point the lens at a zeiss star chart the out of focus donut looks like it might be shifting very slightly in the center. I should have tested the edges though.... but I don't believe in charts at close distance tells the whole story of how a lens might perform. I believe in real world results and to my eyes, I definitely have a problem. I attached a crop of the extreme edge with the left and right side. I finally tried the classic take one picture, rotate the camera and shoot upside down trick. Couldn't be clearer than day. This is at f10. At f8, the right edge is almost unusably soft. It goes from being pretty sharp entirely through the left to falling off in sharpness from the center to the right.

I had a chance to test this lens and when I did, I did not try distant objects, which is something I will do in the future. The street and building shots didn't look as bad, but looking back at images I took with my k-5 and this lens, it had issues on that body as well, so I can rule that out. I contacted the seller and he suggested that I just throw it up on e-bay and make a profit over the relatively low price I paid for it. I may do that, but in a lot of ways I don't feel honest or comfortable doing that. Someone less discerning would likely never mind or notice. Someone that routinely prints over 20" wide would be somewhat understandably upset. I've had this lens for a week. I find it discouraging that the seller didn't offer for me to just send it back to them. It is what I would do, and probably is the right thing to do.

There are a lot of sample variations on this particular lens, and selling it and buying another used is going to be like playing russian roulette I'm afraid. I'm really at a loss of what I should do. My 12-24 is in need of repairs and both my kit lenses, the 18-55 and 28-80 are showing some pretty serious decentering these days which is why I bought this 16-45 in the first place to give me a usable walk around zoom again. What would you all do in this situation? Now I have a non-working k-5 and a k-7 with dust under the sensor's AA filter and no wide to normal lenses. Kind of hard to do landscapes with just telephotos. I'm tempted to just buy a plastic mount 18-55 off keh. They used to be like 50 and now they are 80 or so. Grrrrr. I'm also tempted to just send this lens off to CRIS, but I am not confident they will fix it and worry they will just return it as in spec. It still is cheaper than a new 16-45 to have it repaired, but then I would have invested over 400 and for that amount I likely could just buy a used 17-70 which is probably even sharper at the wide end. I swore off zooms, but then my M28mm 3.5 quit snapping its aperture blades and I really missed having wide angles. I thought the 16-45 would be a good fit for a lot of what I shoot. Where it is sharp it is really nice and the left side of the frame is pretty sharp right up to the edges. That is the kind of lovely performance I was expecting, but instead just disappointment and frustration.

And yeah, sorry if I'm venting a bit. Its a beautiful day. I want to go take some pictures and not have to worry about image quality or come home like I did the other night and have to throw away most of my shots because they were just unusable. Maybe I'm just too picky? When the one side is exhibiting half the resolution as the other edge that's pretty noticable to me and would show right up in a large print. Especially when the rest of the frame is so sharp. I can live with uniform uneveness towards the edges. I'm sure I'm not the only one that would feel this way. I have pretty high standards of image quality, which is what initially attracted me to this lens. What to do....

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05-04-2013, 06:58 AM   #2
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And here is f4 showing the issue far more clearly. The frame gets rather soft from the center to the right. (edit) my first sample was OOF, so I reshot at F4 and uploaded the crop you see now. still not looking great.
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Last edited by zosxavius; 05-04-2013 at 07:14 AM.
05-04-2013, 07:09 AM - 1 Like   #3
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Is this a new purchase? No right of return?

My 16-45 was sharp as hell when new. One day after a couple of years of heavy use and maybe a fall, photos were all soft. I sent it to Pentax Canada for repairs. It came back sharp as ever and the barrel is tighter than when it was new, no wobble at all. I think they charged me about $130. They quoted before making the repair.

It's well worth sending it in IME. You can't sell it in that condition anyway, not if you have a conscience.
05-04-2013, 07:16 AM   #4
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QuoteOriginally posted by audiobomber Quote
Is this a new purchase? No right of return?


It's well worth sending it in IME. You can't sell it in that condition anyway, not if you have a conscience.
2nd hand purchase. Looks like the buyer doesn't want it back either. What a shock. So much for good faith.

So yeah, in all reality I'm just stuck with it.

And yeah, i must add that I don't feel comfortable selling this lens.

Also I'm not buying what I reading in a few other threads (looking at you dpreview) that some people feel this kind of performance is acceptable. Its really not IMO. Astigmatism is no fun.

05-04-2013, 07:38 AM   #5
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QuoteOriginally posted by zosxavius Quote
2nd hand purchase. Looks like the buyer doesn't want it back either. What a shock. So much for good faith.

So yeah, in all reality I'm just stuck with it.

And yeah, i must add that I don't feel comfortable selling this lens.

Also I'm not buying what I reading in a few other threads (looking at you dpreview) that some people feel this kind of performance is acceptable. Its really not IMO. Astigmatism is no fun.
It doesn't look like you got it through the Marketplace here. eBay perhaps? If so there are remedies through PP & eBay for purchasers.
05-04-2013, 07:40 AM   #6
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QuoteOriginally posted by zosxavius Quote
2nd hand purchase. Looks like the buyer doesn't want it back either. What a shock. So much for good faith.

So yeah, in all reality I'm just stuck with it.

And yeah, i must add that I don't feel comfortable selling this lens.

Also I'm not buying what I reading in a few other threads (looking at you dpreview) that some people feel this kind of performance is acceptable. Its really not IMO. Astigmatism is no fun.
I remember reading your first post about this issue, and read back through the thread from the other day. As a seller, I wouldn't take it back - at this point. Unless you've tried the lens on a camera where you haven't removed and changed mounts and re-seated them several times by the sounds of it, all of these tests are just inconclusive. If you look at it from another perspective, let's say you and the seller decide to file an insurance claim for damage. Would you disclose that you've been changing the mounts around on your cameras to USPS (or whatever shipper) - the platform on which you are using to verify something has been damaged in transit? At that point they would probably ask your qualification for doing so, to which the response I'm guessing would be you've never worked for a camera company repairing digital cameras, correct? If on the other hand you can show a clear problem with the lens based on testing with a camera that hasn't been altered, dispute it with paypal if the buyer won't work with you.
05-04-2013, 07:50 AM   #7
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QuoteOriginally posted by pxpaulx Quote
I remember reading your first post about this issue, and read back through the thread from the other day. As a seller, I wouldn't take it back - at this point. Unless you've tried the lens on a camera where you haven't removed and changed mounts and re-seated them several times by the sounds of it, all of these tests are just inconclusive. If you look at it from another perspective, let's say you and the seller decide to file an insurance claim for damage. Would you disclose that you've been changing the mounts around on your cameras to USPS (or whatever shipper) - the platform on which you are using to verify something has been damaged in transit? At that point they would probably ask your qualification for doing so, to which the response I'm guessing would be you've never worked for a camera company repairing digital cameras, correct? If on the other hand you can show a clear problem with the lens based on testing with a camera that hasn't been altered, dispute it with paypal if the buyer won't work with you.
Excellent point. I'd send both the camera and the lens to CRIS and get an estimate at this point.
05-04-2013, 08:18 AM   #8
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QuoteOriginally posted by audiobomber Quote
Is this a new purchase? No right of return?

My 16-45 was sharp as hell when new. One day after a couple of years of heavy use and maybe a fall, photos were all soft. I sent it to Pentax Canada for repairs. It came back sharp as ever and the barrel is tighter than when it was new, no wobble at all. I think they charged me about $130. They quoted before making the repair.

It's well worth sending it in IME. You can't sell it in that condition anyway, not if you have a conscience.
It's interesting that you were able to get your barrel wobble corrected. The problem with barrel wobble is that nobody knows what the specification for it is or how to (physically) measure it to compare to a specification. It would be interesting to know if anyone else has been successful in eliminating the wobble. I'm not even aware of any new copies that don't wobble.

Paul

05-04-2013, 08:20 AM   #9
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QuoteOriginally posted by pxpaulx Quote
I remember reading your first post about this issue, and read back through the thread from the other day. As a seller, I wouldn't take it back - at this point. Unless you've tried the lens on a camera where you haven't removed and changed mounts and re-seated them several times by the sounds of it, all of these tests are just inconclusive. If you look at it from another perspective, let's say you and the seller decide to file an insurance claim for damage. Would you disclose that you've been changing the mounts around on your cameras to USPS (or whatever shipper) - the platform on which you are using to verify something has been damaged in transit? At that point they would probably ask your qualification for doing so, to which the response I'm guessing would be you've never worked for a camera company repairing digital cameras, correct? If on the other hand you can show a clear problem with the lens based on testing with a camera that hasn't been altered, dispute it with paypal if the buyer won't work with you.
I fully agree. However looking back through the two days it was mounted on my k-5 I had the same issues on that body which was fine with my other lenses before all of this started. I went back through all of my lenses and none of them look remotely misaligned to this degree. I will test on another pentax body as soon as I can get to my friend and try his k-10. I will also try another k-5 if I can get my other friend to come meet me, but if all my other lenses look the same as they always have on this k-7 I see no issues with the mount. When I had a warped mount ring, I certainly had softness issues. The mount sits flush in the body. There isn't a lot of room for movement off plane if the screws are tightened properly and you seat it properly before tightening. After changing them a few times I don't think there is any real ill effect as long as the ring is perfectly flat. I reseated the ring a couple of times just to make sure that somehow I didn't tighten it well. The first time I changed one I did not seat it properly and I had to loosen the screws and retighten and all was well. I wanted to make sure that wasn't the case. After that there were no optical issues at all. I need to send a few things off to CRIS, but that lens cost me all the money I will have for a moment. Thinking I should have tried KEH actually.

I've repaired lenses before btw as well as many other mechanical things, but once again I don't know what I'm doing right ? its all my fault? Sorry, I'm just tired of blaming the user initially. Its a pretty common response. Why are all my other lenses far sharper across the whole frame except just this one? My 50 is tack sharp. any misregistration from flange distance should show up easily at infinity. When you are faced with equipment that isn't worth fixing and operating on a shoestring budget some times you have to do what you can to make things work yourself. My k-7 has some issues, but the mount is not one of them. My 28mm and 50mm both look superb on it from edge to edge. The 28-80 looks pretty decent too for as tattered as my copy has become. This lens does not look good. My opinion is that it is bad. My only recourse is to send it in I guess.
05-04-2013, 08:26 AM   #10
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QuoteOriginally posted by zosxavius Quote
I fully agree. However looking back through the two days it was mounted on my k-5 I had the same issues on that body which was fine with my other lenses before all of this started. I went back through all of my lenses and none of them look remotely misaligned to this degree. I will test on another pentax body as soon as I can get to my friend and try his k-10. I will also try another k-5 if I can get my other friend to come meet me, but if all my other lenses look the same as they always have on this k-7 I see no issues with the mount. When I had a warped mount ring, I certainly had softness issues. The mount sits flush in the body. There isn't a lot of room for movement off plane if the screws are tightened properly and you seat it properly before tightening. After changing them a few times I don't think there is any real ill effect as long as the ring is perfectly flat. I reseated the ring a couple of times just to make sure that somehow I didn't tighten it well. The first time I changed one I did not seat it properly and I had to loosen the screws and retighten and all was well. I wanted to make sure that wasn't the case. After that there were no optical issues at all. I need to send a few things off to CRIS, but that lens cost me all the money I will have for a moment. Thinking I should have tried KEH actually.

I've repaired lenses before btw as well as many other mechanical things, but once again I don't know what I'm doing right ? its all my fault? Sorry, I'm just tired of blaming the user initially. Its a pretty common response. Why are all my other lenses far sharper across the whole frame except just this one? My 50 is tack sharp. any misregistration from flange distance should show up easily at infinity. When you are faced with equipment that isn't worth fixing and operating on a shoestring budget some times you have to do what you can to make things work yourself. My k-7 has some issues, but the mount is not one of them. My 28mm and 50mm both look superb on it from edge to edge. The 28-80 looks pretty decent too for as tattered as my copy has become. This lens does not look good. My opinion is that it is bad. My only recourse is to send it in I guess.
I don't think anyone said it was all your fault. This is about whether you can legitimately make the claim that it was damaged in transit or defective when sold to you. Without an unadulterated camera upon which to test the lens that claim can not legitimately be made IMHO. Fix what you like, tinker to your hearts content, but if you do, and are not an acknowledged Pentax service technician, do not expect the warranty or 3rd party to take the item back. That goes for everything we buy these days.
05-04-2013, 08:49 AM   #11
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QuoteOriginally posted by Docrwm Quote
I don't think anyone said it was all your fault. This is about whether you can legitimately make the claim that it was damaged in transit or defective when sold to you. Without an unadulterated camera upon which to test the lens that claim can not legitimately be made IMHO. Fix what you like, tinker to your hearts content, but if you do, and are not an acknowledged Pentax service technician, do not expect the warranty or 3rd party to take the item back. That goes for everything we buy these days.
True enough. I've had a few problems before with some things and as soon as I mention any attempt to repair them I am often blamed for them being broken in the first place, etc. And please forgive me for not exactly being a happy camper at this moment. Photography is a drug and I'm a serious junky on sudden withdrawal. I pretty much have given up on having any sort of recourse. Its a mostly unused copy, so I guess I just scrape together another couple hundred and send it off to CRIS. I'm reluctact to send the k-7. I need some kind of working camera. For events and people shots I don't need the best lens in the world. A slightly decentered 28-80 doesn't look that bad on close objects.
05-04-2013, 08:55 AM   #12
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QuoteOriginally posted by zosxavius Quote
True enough. I've had a few problems before with some things and as soon as I mention any attempt to repair them I am often blamed for them being broken in the first place, etc. And please forgive me for not exactly being a happy camper at this moment. Photography is a drug and I'm a serious junky on sudden withdrawal. I pretty much have given up on having any sort of recourse. Its a mostly unused copy, so I guess I just scrape together another couple hundred and send it off to CRIS. I'm reluctact to send the k-7. I need some kind of working camera. For events and people shots I don't need the best lens in the world. A slightly decentered 28-80 doesn't look that bad on close objects.
I understand, it really is frustrating when gear doesn't work. I'd send the items in one at a time.
05-04-2013, 08:58 AM   #13
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QuoteOriginally posted by Docrwm Quote
It doesn't look like you got it through the Marketplace here. eBay perhaps? If so there are remedies through PP & eBay for purchasers.
I bought it through someone from the pentax community on facebook. They were travelling into my town and had a copy of the lens for sale. The price was right. I didn't have much time to really test it all that properly. Close objects seemed ok. Never thought about testing it at infinity. I did see some softness but thought it might have been field curvature or focusing error. Then my k-5 died and I pressed the k-7 back into use. I spent the next week trying to figure out why all my shots were soft then sadly decided that I just have a bad lens. I will have to test on another camera out of curiosity more than anything, but I suspect the same result. I looked back through what I did shoot with it on the k-5 and it had the same softness issues. At f9 they are less noticable obviously than f4. I learned to A) test lenses at infinity, B) test them wide open where they are softest, and C) the brick wall and flipped camera trick always do wonders.
05-04-2013, 09:00 AM   #14
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Whenever someone posts something like this, I wonder why they do so. Is there a genuine request for advice? Is there a genuine need? Fair enough that this appears in troubleshooting, but as a casual reader, so many red flags pop up and need to be said.

The OP has a problem that he feels is caused by a lens being de-centered.
Buying *used* implies "Not New". It always amazes me that people that buy used expect new? The moment a lens/camera leave a factory they are jostled and bumped and handled before they get into the hands of the first consumer. Any lens that is sold after new is going to be a risk.

Good thing Pentax lenses are pretty good used, but they are still "used".

If you end up with an item that is not going to be taken back, then the discount/gamble in being used sometimes doesn't pay-off.

It happens to me ALL THE TIME. Sometimes I buy new, sometimes I take the gamble.

Case in point. I just bought an SMC-A F/4. 100mm Macro. The eBay listing (KEH) said some hazing. I thought "How bad could it be?" $150 later, and it's on my doorstep. Yeah, the hazing was pretty bad, but DAMN does it produce sharp images - and I can't see where the hazing affects the image. Cool. Win/Lose depending on how it goes. It's part of the FUN of used sometimes.

So now the OP has a lens that falls short of his expectations of extreme sharpness in areas of the image that do not fit his expectation - and was bought used with no warranty.

Don't make things WORSE. Send it to Pentax. Any other solution/attempt is only causing further pain.

1) Switching mounts from camera to camera?
2) Shimming the mount?
3) Sending it to KEH to be repaired instead of Pentax?

C'mon. Stop hitting yourself in the hand with the hammer!
05-04-2013, 09:09 AM   #15
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QuoteOriginally posted by LaurenOE Quote
Whenever someone posts something like this, I wonder why they do so. Is there a genuine request for advice? Is there a genuine need? Fair enough that this appears in troubleshooting, but as a casual reader, so many red flags pop up and need to be said.

The OP has a problem that he feels is caused by a lens being de-centered.
Buying *used* implies "Not New". It always amazes me that people that buy used expect new? The moment a lens/camera leave a factory they are jostled and bumped and handled before they get into the hands of the first consumer. Any lens that is sold after new is going to be a risk.

Good thing Pentax lenses are pretty good used, but they are still "used".

If you end up with an item that is not going to be taken back, then the discount/gamble in being used sometimes doesn't pay-off.

It happens to me ALL THE TIME. Sometimes I buy new, sometimes I take the gamble.

Case in point. I just bought an SMC-A F/4. 100mm Macro. The eBay listing (KEH) said some hazing. I thought "How bad could it be?" $150 later, and it's on my doorstep. Yeah, the hazing was pretty bad, but DAMN does it produce sharp images - and I can't see where the hazing affects the image. Cool. Win/Lose depending on how it goes. It's part of the FUN of used sometimes.

So now the OP has a lens that falls short of his expectations of extreme sharpness in areas of the image that do not fit his expectation - and was bought used with no warranty.

Don't make things WORSE. Send it to Pentax. Any other solution/attempt is only causing further pain.

1) Switching mounts from camera to camera?
2) Shimming the mount?
3) Sending it to KEH to be repaired instead of Pentax?

C'mon. Stop hitting yourself in the hand with the hammer!
LOL. Well said. Thanks to those that responded btw. Feeling a little grumpy today.
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