Question for 16-50mm owners

TanGU · 10-21-2008, 09:08 AM

hi guys,

I just received my 16-50mm and i'm not sure it is a good copy, when i did a Focus Test chart, it show that the left side is less clear than the right side.

I have a K10D btw

here some example:
Exposure: 1/100 sec
Aperture: f/3.2
Focal Length: 50mm
http://picasaweb.google.com/herouxb/Test1650mm#5259635912910609618

Exposure: 1/100 sec
Aperture: f/5.6
Focal Length: 50mm
http://picasaweb.google.com/herouxb/Test1650mm#5259636097823806882

Exposure: 1/100 sec
Aperture: f/9.0
Focal Length: 50mm
http://picasaweb.google.com/herouxb/Test1650mm#5259636306444128594

Exposure: 1/125 sec
Aperture: f/2.8
Focal Length: 16mm
http://picasaweb.google.com/herouxb/Test1650mm#5259434340890267074

EDIT: you can zoom in the image now...

So... what do you guys think ?

thanks!

Last edited by TanGU; 10-21-2008 at 11:03 AM.

k100d · 10-21-2008, 09:18 AM

your samples aren't showing.
but if it's what i'm thinking it is, most likely this is an issue with decentering. time to send it in

PentaxPoke · 10-21-2008, 09:38 AM

Don't waste any more time on the 16-50 merry-go-round. Return the lens, and get a Tamron 17-50.

See links below:

https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/35735-da-16-50...-round-ii.html

https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/29218-tamron-1...throwdown.html

TanGU · 10-21-2008, 09:54 AM

I did another test:
http://picasaweb.google.com/herouxb/Test1650mm#5259649787558207186

If you compare Lisa and Maggie... is it a good test by the way?

Last edited by TanGU; 10-21-2008 at 11:04 AM.

PentaxPoke · 10-21-2008, 10:21 AM

Your images are still not visible.

TanGU · 10-21-2008, 11:05 AM

Originally posted by PentaxPoke

Your images are still not visible.

Ah sorry... it is picassa problem, so i include the link instead of showing the image directly, because the URL seem to change

PentaxPoke · 10-21-2008, 11:39 AM

Looks softer on the left to me. The brick wall shows really bad "mustache" distortion at 16mm. That is typical for this lens though.

To verify you might try a bigger brick wall from farther away so any camera angle affects are minimized.

I agree with k100d about the decentering. Did you look through the two links I posted?

Last edited by PentaxPoke; 10-21-2008 at 12:46 PM.

John K · 10-21-2008, 02:19 PM

replying to your post - looks very similar to mine but in reverse - mine goes out of focus on the right side. Pity - otherwise, the lens seemed to work very nicely.

Cooties · 10-21-2008, 06:37 PM

Bit of a thread dig up, but yesterday I received this exact lens (serial number 9013560) from (a popular Sydney online retailer) and have come to the conclusion that it is indeed a crap lens and should go straight in the bin.

Right side of the lens is rubbish up to f8 from 16mm to ~35mm, left side is bad at 50mm (how does that work ??).

I have arranged to have this lens replaced but I just thought I'd give this forum a search and see if the serial number popped up... Not real impressed to say the least. I knew something was up when the serial number on the box didn't match the lens and the aperture lever on the lens mount was worn.

Not sure if its against forum rules to "name and shame" but at least this store has been good in replying to my emails and sorting out a replacement. Hopefully I'll get a new lens this time.

**Mallee Boy** · 10-21-2008, 08:48 PM

Originally posted by Cooties

Bit of a thread dig up, but yesterday I received this exact lens (serial number 9013560) from (a popular Sydney online retailer) and have come to the conclusion that it is indeed a crap lens and should go straight in the bin.

Right side of the lens is rubbish up to f8 from 16mm to ~35mm, left side is bad at 50mm (how does that work ??).

I have arranged to have this lens replaced but I just thought I'd give this forum a search and see if the serial number popped up... Not real impressed to say the least. I knew something was up when the serial number on the box didn't match the lens and the aperture lever on the lens mount was worn.

Not sure if its against forum rules to "name and shame" but at least this store has been good in replying to my emails and sorting out a replacement. Hopefully I'll get a new lens this time.

Now that is a big concern.

I have long wondered what happens when lenses are returned. How easy it would be just to pop it back into a box and send it off to the next person.

The lady from Adorama assured me that they (Adorama) would not do this as they had a policy of shipping un-opened boxes only.
I found this out only after asking her if someone at Adorama would open the box, take some shots with the lens and email the shots to avoid exactly this situation. Not unsurprisingly that request was refused, and thats when the shipping policy came to light, from that particular store.

It is sad and dis-appointing to hear your story, and yes, I think you have every right to name. Afterall, they all enjoy the praise when its being offered.

nulla · 10-21-2008, 11:32 PM

I too would name and shame.

If they come to the party and replace with a good one then name and fame them

Neil

TanGU · 10-22-2008, 04:24 AM

Originally posted by PentaxPoke

Looks softer on the left to me. The brick wall shows really bad "mustache" distortion at 16mm. That is typical for this lens though.

To verify you might try a bigger brick wall from farther away so any camera angle affects are minimized.

I agree with k100d about the decentering. Did you look through the two links I posted?

It weird isn't it? because it is not a front or back focus problem that everyone seem to complain about this lens, maybe a new problem?

I read your post, but the Pentax is better to me because of it sealing... thx anyway

Matt Miller · 10-22-2008, 05:23 AM

Originally posted by TanGU

It weird isn't it? because it is not a front or back focus problem that everyone seem to complain about this lens, maybe a new problem?

I read your post, but the Pentax is better to me because of it sealing... thx anyway

It's definitely not a new problem. There are many threads discussing this "decentering" problem. I've gone through two bad copies from an ebay seller recently. Both had this same problem, mushy on one side. Didn't even get to test the front/back focusing, just sent them back.

I'd really like to find a perfect copy of this lens, but am losing hope.

TanGU · 10-22-2008, 06:06 AM

Originally posted by Matt Miller

It's definitely not a new problem. There are many threads discussing this "decentering" problem. I've gone through two bad copies from an ebay seller recently. Both had this same problem, mushy on one side. Didn't even get to test the front/back focusing, just sent them back.

I'd really like to find a perfect copy of this lens, but am losing hope.

ah... so that a "decentering" problem... okay i didn't know what it mean.

I'll do some other test tomorrow with a tripod and real life test shot to see if it is really bugging me that much

Btw, i won't buy that lens on ebay if i were you...try in store (like me! haha)

John K · 10-22-2008, 11:04 AM

For anyone who sent their lens back for replacement, how many replacements is it taking before you got a good one? Mine is off at the right edge but tolerable if I don't need to use the right 10% of the shot and crop it out.
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crop of centre: Name: inlet-centre.jpg
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View Poll Results: Is this DA*16-50mm good or bad?
Keep it -- it's good.	23	88.46%
Return it or send it in for repair.	3	11.54%
Voters: 26. You may not vote on this poll

10-21-2008, 09:08 AM	#946
TanGU Inactive Account Join Date: Jul 2008 Location: Longueuil, QC Photos: Gallery Posts: 90	Pentax 16-50mm with soft left side ? hi guys, I just received my 16-50mm and i'm not sure it is a good copy, when i did a Focus Test chart, it show that the left side is less clear than the right side. I have a K10D btw here some example: Exposure: 1/100 sec Aperture: f/3.2 Focal Length: 50mm http://picasaweb.google.com/herouxb/Test1650mm#5259635912910609618 Exposure: 1/100 sec Aperture: f/5.6 Focal Length: 50mm http://picasaweb.google.com/herouxb/Test1650mm#5259636097823806882 Exposure: 1/100 sec Aperture: f/9.0 Focal Length: 50mm http://picasaweb.google.com/herouxb/Test1650mm#5259636306444128594 Exposure: 1/125 sec Aperture: f/2.8 Focal Length: 16mm http://picasaweb.google.com/herouxb/Test1650mm#5259434340890267074 EDIT: you can zoom in the image now... So... what do you guys think ? thanks! Last edited by TanGU; 10-21-2008 at 11:03 AM.

10-22-2008, 11:04 AM	#960
John K New Member Join Date: Sep 2008 Location: Cork, Ireland Posts: 19	For anyone who sent their lens back for replacement, how many replacements is it taking before you got a good one? Mine is off at the right edge but tolerable if I don't need to use the right 10% of the shot and crop it out. whole frame: crop of centre: crop of right edge: If I ignore the edges completely, the lens works just fine: Last edited by John K; 10-22-2008 at 11:20 AM.

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10-21-2008, 09:18 AM	#947
k100d Veteran Member Join Date: Feb 2008 Location: Toronto Posts: 3,911	your samples aren't showing. but if it's what i'm thinking it is, most likely this is an issue with decentering. time to send it in

10-21-2008, 09:38 AM	#948
PentaxPoke Veteran Member Join Date: Jan 2008 Location: Oklahoma Posts: 1,411	Don't waste any more time on the 16-50 merry-go-round. Return the lens, and get a Tamron 17-50. See links below: https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/35735-da-16-50...-round-ii.html https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/29218-tamron-1...throwdown.html

10-21-2008, 09:54 AM	#949
TanGU Inactive Account Join Date: Jul 2008 Location: Longueuil, QC Photos: Gallery Posts: 90	I did another test: http://picasaweb.google.com/herouxb/Test1650mm#5259649787558207186 If you compare Lisa and Maggie... is it a good test by the way? Last edited by TanGU; 10-21-2008 at 11:04 AM.

10-21-2008, 10:21 AM	#950
PentaxPoke Veteran Member Join Date: Jan 2008 Location: Oklahoma Posts: 1,411	Your images are still not visible.

10-21-2008, 11:05 AM	#951
TanGU Inactive Account Join Date: Jul 2008 Location: Longueuil, QC Photos: Gallery Posts: 90	Originally posted by PentaxPoke Your images are still not visible. Ah sorry... it is picassa problem, so i include the link instead of showing the image directly, because the URL seem to change

10-21-2008, 11:39 AM	#952
PentaxPoke Veteran Member Join Date: Jan 2008 Location: Oklahoma Posts: 1,411	Looks softer on the left to me. The brick wall shows really bad "mustache" distortion at 16mm. That is typical for this lens though. To verify you might try a bigger brick wall from farther away so any camera angle affects are minimized. I agree with k100d about the decentering. Did you look through the two links I posted? Last edited by PentaxPoke; 10-21-2008 at 12:46 PM.

10-21-2008, 02:19 PM	#953
John K New Member Join Date: Sep 2008 Location: Cork, Ireland Posts: 19	replying to your post - looks very similar to mine but in reverse - mine goes out of focus on the right side. Pity - otherwise, the lens seemed to work very nicely.

10-21-2008, 06:37 PM	#954
Cooties New Member Join Date: Oct 2008 Location: Brisbane, Australia Posts: 9	Bit of a thread dig up, but yesterday I received this exact lens (serial number 9013560) from (a popular Sydney online retailer) and have come to the conclusion that it is indeed a crap lens and should go straight in the bin. Right side of the lens is rubbish up to f8 from 16mm to ~35mm, left side is bad at 50mm (how does that work ??). I have arranged to have this lens replaced but I just thought I'd give this forum a search and see if the serial number popped up... Not real impressed to say the least. I knew something was up when the serial number on the box didn't match the lens and the aperture lever on the lens mount was worn. Not sure if its against forum rules to "name and shame" but at least this store has been good in replying to my emails and sorting out a replacement. Hopefully I'll get a new lens this time.

10-21-2008, 08:48 PM	#955
Mallee Boy Site Supporter Join Date: Sep 2006 Location: South Australia Photos: Gallery \| Albums Posts: 3,904	Originally posted by Cooties Bit of a thread dig up, but yesterday I received this exact lens (serial number 9013560) from (a popular Sydney online retailer) and have come to the conclusion that it is indeed a crap lens and should go straight in the bin. Right side of the lens is rubbish up to f8 from 16mm to ~35mm, left side is bad at 50mm (how does that work ??). I have arranged to have this lens replaced but I just thought I'd give this forum a search and see if the serial number popped up... Not real impressed to say the least. I knew something was up when the serial number on the box didn't match the lens and the aperture lever on the lens mount was worn. Not sure if its against forum rules to "name and shame" but at least this store has been good in replying to my emails and sorting out a replacement. Hopefully I'll get a new lens this time. Now that is a big concern. I have long wondered what happens when lenses are returned. How easy it would be just to pop it back into a box and send it off to the next person. The lady from Adorama assured me that they (Adorama) would not do this as they had a policy of shipping un-opened boxes only. I found this out only after asking her if someone at Adorama would open the box, take some shots with the lens and email the shots to avoid exactly this situation. Not unsurprisingly that request was refused, and thats when the shipping policy came to light, from that particular store. It is sad and dis-appointing to hear your story, and yes, I think you have every right to name. Afterall, they all enjoy the praise when its being offered.

10-21-2008, 11:32 PM	#956
nulla Veteran Member Join Date: Jul 2008 Location: Melbourne Australia Posts: 1,560	I too would name and shame. If they come to the party and replace with a good one then name and fame them Neil

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10-22-2008, 04:24 AM	#957
TanGU Inactive Account Join Date: Jul 2008 Location: Longueuil, QC Photos: Gallery Posts: 90	Originally posted by PentaxPoke Looks softer on the left to me. The brick wall shows really bad "mustache" distortion at 16mm. That is typical for this lens though. To verify you might try a bigger brick wall from farther away so any camera angle affects are minimized. I agree with k100d about the decentering. Did you look through the two links I posted? It weird isn't it? because it is not a front or back focus problem that everyone seem to complain about this lens, maybe a new problem? I read your post, but the Pentax is better to me because of it sealing... thx anyway

10-22-2008, 05:23 AM	#958
Matt Miller Veteran Member Join Date: May 2007 Location: Cambridge, Iowa Photos: Gallery Posts: 339	Originally posted by TanGU It weird isn't it? because it is not a front or back focus problem that everyone seem to complain about this lens, maybe a new problem? I read your post, but the Pentax is better to me because of it sealing... thx anyway It's definitely not a new problem. There are many threads discussing this "decentering" problem. I've gone through two bad copies from an ebay seller recently. Both had this same problem, mushy on one side. Didn't even get to test the front/back focusing, just sent them back. I'd really like to find a perfect copy of this lens, but am losing hope.

10-22-2008, 06:06 AM	#959
TanGU Inactive Account Join Date: Jul 2008 Location: Longueuil, QC Photos: Gallery Posts: 90	Originally posted by Matt Miller It's definitely not a new problem. There are many threads discussing this "decentering" problem. I've gone through two bad copies from an ebay seller recently. Both had this same problem, mushy on one side. Didn't even get to test the front/back focusing, just sent them back. I'd really like to find a perfect copy of this lens, but am losing hope. ah... so that a "decentering" problem... okay i didn't know what it mean. I'll do some other test tomorrow with a tripod and real life test shot to see if it is really bugging me that much Btw, i won't buy that lens on ebay if i were you...try in store (like me! haha)