Comments on: Testing for a Decentered Lens: an Old Technique Gets a Makeover http://www.lensrentals.com/blog/2012/05/testing-for-a-decentered-lens-an-old-technique-gets-a-makeover Photo/video thoughts from the largest rental house Mon, 20 May 2013 18:16:41 +0000 hourly 1 http://wordpress.org/?v=3.3.2 By: Norbe http://www.lensrentals.com/blog/2012/05/testing-for-a-decentered-lens-an-old-technique-gets-a-makeover/comment-page-1#comment-37908 Norbe Fri, 03 May 2013 03:12:57 +0000 http://www.lensrentals.com/blog/?p=6857#comment-37908 I just sent my Sigma 70-200 f2.8 HSM II back to Sigma in NY for the decentered problem. Center is shape, but left and right are blurry. They emailed back saying the lens is being sent to Japan for repair. So, it seems that they do not have the equipment in the US to make the adjustment. Just reserved one on rental to fill the gap. I just sent my Sigma 70-200 f2.8 HSM II back to Sigma in NY for the decentered problem. Center is shape, but left and right are blurry. They emailed back saying the lens is being sent to Japan for repair. So, it seems that they do not have the equipment in the US to make the adjustment. Just reserved one on rental to fill the gap.

]]> By: Roger Cicala http://www.lensrentals.com/blog/2012/05/testing-for-a-decentered-lens-an-old-technique-gets-a-makeover/comment-page-1#comment-37899 Roger Cicala Thu, 02 May 2013 21:43:21 +0000 http://www.lensrentals.com/blog/?p=6857#comment-37899 Kate, only the center target is pertinent with this test. Coma and other aberrations will affect the off center dots in a normal lens. Kate, only the center target is pertinent with this test. Coma and other aberrations will affect the off center dots in a normal lens.

]]> By: Kate http://www.lensrentals.com/blog/2012/05/testing-for-a-decentered-lens-an-old-technique-gets-a-makeover/comment-page-1#comment-37894 Kate Thu, 02 May 2013 17:52:08 +0000 http://www.lensrentals.com/blog/?p=6857#comment-37894 I am testing a Sigma 24-70mm because lately when I am shooting it seems that the center of my image is sharp, and the focus gets softer on the left side. When doing your test with the circles, the corners seem to only show slight change in the center dot. Is this normal? Should the center target be the only one showing misalignment?? I am testing a Sigma 24-70mm because lately when I am shooting it seems that the center of my image is sharp, and the focus gets softer on the left side. When doing your test with the circles, the corners seem to only show slight change in the center dot. Is this normal? Should the center target be the only one showing misalignment??

]]> By: Roger Cicala http://www.lensrentals.com/blog/2012/05/testing-for-a-decentered-lens-an-old-technique-gets-a-makeover/comment-page-1#comment-30621 Roger Cicala Tue, 26 Feb 2013 21:18:22 +0000 http://www.lensrentals.com/blog/?p=6857#comment-30621 Bradley, I wouldn't laminate it unless you can get a low-glare covering and even then I'd be hesitant. It's made to be the first surface and adding a diffraction layer might cause an issue. It might not, too, but for critical testing I think it best not to add another variable. Bradley, I wouldn’t laminate it unless you can get a low-glare covering and even then I’d be hesitant. It’s made to be the first surface and adding a diffraction layer might cause an issue. It might not, too, but for critical testing I think it best not to add another variable.

]]> By: Bradley http://www.lensrentals.com/blog/2012/05/testing-for-a-decentered-lens-an-old-technique-gets-a-makeover/comment-page-1#comment-30609 Bradley Tue, 26 Feb 2013 16:42:53 +0000 http://www.lensrentals.com/blog/?p=6857#comment-30609 I just picked up a Zeiss Siemens Star Test Chart to check for lens focus and decentering. Well, I just ordered it. I'm assuming that it is just a piece of paper or thin cardboard, right? If so, can it be laminated in plastic without any effect on it's quality or use? I just picked up a Zeiss Siemens Star Test Chart to check for lens focus and decentering. Well, I just ordered it. I’m assuming that it is just a piece of paper or thin cardboard, right? If so, can it be laminated in plastic without any effect on it’s quality or use?

]]> By: Pro http://www.lensrentals.com/blog/2012/05/testing-for-a-decentered-lens-an-old-technique-gets-a-makeover/comment-page-1#comment-29828 Pro Fri, 15 Feb 2013 14:13:41 +0000 http://www.lensrentals.com/blog/?p=6857#comment-29828 Hallo, a couple of years ago I bought a D700 with a Nikon 24-70 2.8. The left side of the frame was out of focus but not always so I suspected that an element must been loose. I sent it to Nikon service and after 15 day the said that they calibrate the af of the lens and everything was ok. I find that answer idiot. Since the lens was new I demanded a replacement and after a month a new lens arrived. Better copy but same problem.One shot perfect , 9 shots average .The body was wonderful providing nice pictures at 2500 ISO but the lens...So I sold all the Nikon gear and continued with my reliable 17-55 on my 30D!( yes I bought the D700 instead of the 5DmkII because of the better ISO performance) Hallo, a couple of years ago I bought a D700 with a Nikon 24-70 2.8. The left side of the frame was out of focus but not always so I suspected that an element must been loose. I sent it to Nikon service and after 15 day the said that they calibrate the af of the lens and everything was ok. I find that answer idiot. Since the lens was new I demanded a replacement and after a month a new lens arrived. Better copy but same problem.One shot perfect , 9 shots average .The body was wonderful providing nice pictures at 2500 ISO but the lens…So I sold all the Nikon gear and continued with my reliable 17-55 on my 30D!( yes I bought the D700 instead of the 5DmkII because of the better ISO performance)

]]> By: Raul http://www.lensrentals.com/blog/2012/05/testing-for-a-decentered-lens-an-old-technique-gets-a-makeover/comment-page-1#comment-27861 Raul Sun, 27 Jan 2013 09:55:26 +0000 http://www.lensrentals.com/blog/?p=6857#comment-27861 I'm trying to determine if a Sony SELP 16-50 is defective (kit lens on NEX-6). In the middle of the zoom range, the left side of the image is significantly softer than the right. It affects about 15 % of the width, an does not improve much when stopping down. This is my second copy of the lens. The first one had this problem at the wider end of the zoom range. Am I unlucky, or this lens has poor manufacturing tolerances? Roger, have you tested any of these lenses? I’m trying to determine if a Sony SELP 16-50 is defective (kit lens on NEX-6). In the middle of the zoom range, the left side of the image is significantly softer than the right. It affects about 15 % of the width, an does not improve much when stopping down. This is my second copy of the lens. The first one had this problem at the wider end of the zoom range. Am I unlucky, or this lens has poor manufacturing tolerances? Roger, have you tested any of these lenses?

]]> By: Roger Cicala http://www.lensrentals.com/blog/2012/05/testing-for-a-decentered-lens-an-old-technique-gets-a-makeover/comment-page-1#comment-26989 Roger Cicala Fri, 11 Jan 2013 16:05:52 +0000 http://www.lensrentals.com/blog/?p=6857#comment-26989 Vlad, worse towards the edges, if it's symetrical, is pretty normal. All the various abberations can make that happen away from center. Vlad, worse towards the edges, if it’s symetrical, is pretty normal. All the various abberations can make that happen away from center.

]]> By: Vlad http://www.lensrentals.com/blog/2012/05/testing-for-a-decentered-lens-an-old-technique-gets-a-makeover/comment-page-1#comment-26987 Vlad Fri, 11 Jan 2013 15:47:17 +0000 http://www.lensrentals.com/blog/?p=6857#comment-26987 Should there be decentered flaring on the circles other then the one in the center of the lens? I'm asking because I have a Sigma 50mm 1.4 which suffers from erratic AF an I tested using the black background and white circles. When slightly OOF I can see that the center is ok but the rest whould be decentered going worse to the edges. Thanks Should there be decentered flaring on the circles other then the one in the center of the lens?

I’m asking because I have a Sigma 50mm 1.4 which suffers from erratic AF an I tested using the black background and white circles. When slightly OOF I can see that the center is ok but the rest whould be decentered going worse to the edges.

Thanks

]]> By: Roger Cicala http://www.lensrentals.com/blog/2012/05/testing-for-a-decentered-lens-an-old-technique-gets-a-makeover/comment-page-1#comment-26508 Roger Cicala Fri, 04 Jan 2013 12:43:47 +0000 http://www.lensrentals.com/blog/?p=6857#comment-26508 sergejv, I don't think that can be a lens issue = on 1 or even 2 lenses, perhaps, but not 5. But to answer the question we haven't seen any problems with 24-70s and lateral autofocus. Excepting, of course, a couple of copies that were decentered. sergejv, I don’t think that can be a lens issue = on 1 or even 2 lenses, perhaps, but not 5. But to answer the question we haven’t seen any problems with 24-70s and lateral autofocus. Excepting, of course, a couple of copies that were decentered.

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