Sigma lens soft focus
Feb 9, 2012 21:42:35 #
I shoot with a Sigma 18-250 zoom on a Nikon D-90 and have encountered a problem with it. The vast majority of the pictures are soft and appear to be focusing past the point I am aiming at. My other lenses (Nikon and Tamron) do not have this issue, so I don't think it is the camera. Has anyone else encountered focus issues with Sigma lenses?
Feb 9, 2012 21:47:06 #
i have had nothing but good luck with sigma lenses. their shoe mount flash guns on the other hand i would not touch with a 10 ft pole.
Feb 9, 2012 22:12:45 #
Your lens has a "sweet" range from F8-F11, anything faster tends to get soft at the long end of the zoom. It should be quite sharp at the short end at all aperture settings. This actually pretty common in most zooms that go over 10X. They focus very well in manual.
Feb 9, 2012 22:48:23 #
If you are correct, that lens has a back-focus issue. I don't think the D90 has the feature to adjust that problem. Not much help, am I.
I suppose you could send it to Sigma for a test. This is one area in which buying lenses from the same mfg. as the camera can pay off - you can send the body and lens in for a check and repair if needed.
I suppose you could send it to Sigma for a test. This is one area in which buying lenses from the same mfg. as the camera can pay off - you can send the body and lens in for a check and repair if needed.
Feb 10, 2012 03:51:06 #
Are you shooting your camera with all the focal points working? I've found with my Canon cameras that with all the points working the camera often grabs something other than what I wanted.
So I switched them both to single point focus. The camera has no choice but to focus where I place that single point.
On Canon cameras you need to be out of full auto to shoot with a single point - I don't know about Nikon. You might check your owner's manual for these instructions.
It's something to try at least. If this still doesn't work then it may be a lens problem sence you say your other lenses are working fine.
Good Luck
So I switched them both to single point focus. The camera has no choice but to focus where I place that single point.
On Canon cameras you need to be out of full auto to shoot with a single point - I don't know about Nikon. You might check your owner's manual for these instructions.
It's something to try at least. If this still doesn't work then it may be a lens problem sence you say your other lenses are working fine.
Good Luck
Feb 10, 2012 03:56:11 #
Yep....backfocusing...that's a shame.
The only thing you can do is to send it in and have it fixed.
The only thing you can do is to send it in and have it fixed.
Feb 10, 2012 05:42:32 #
Florida Shooter
Loc: Lake Worth, FL
I have a problem with their 70/200 on my D7000. Sigma will calibrate the lens free but you must send in your lens and camera.
Feb 10, 2012 06:20:43 #
Feb 10, 2012 06:55:32 #
Thanks for the info. I'll experiment in that F/stop range and see if I can get sharper pictures. I generally need the longer range for pictures, but the short end does seem better.
Feb 10, 2012 06:55:56 #
TimW wrote:
I shoot with a Sigma 18-250 zoom on a Nikon D-90 and have encountered a problem with it. The vast majority of the pictures are soft and appear to be focusing past the point I am aiming at. My other lenses (Nikon and Tamron) do not have this issue, so I don't think it is the camera. Has anyone else encountered focus issues with Sigma lenses?
Feb 10, 2012 06:57:04 #
You are right that the D-90 doesn't have any focus correction adjustment. SIgma said they'd re-calibrate the lens so I'm trying that , though it has been done once before. We'll see. Thanks for the post.
Feb 10, 2012 07:00:14 #
I try to avoid using all focus points for that very reason (someitmes I don't realize which point the camera picked). My latest batch was with only the central pocus point. Sigma is re-calibrating the lens so we'll see how that goes. Thanks for the suggestion.
Feb 10, 2012 07:01:04 #
Hi. I don't believe it is intentional, but I'll certainly check i tout as it would explain things. Thanks.
Feb 10, 2012 08:48:36 #
Florida Shooter wrote:
I have a problem with their 70/200 on my D7000. Sigma will calibrate the lens free but you must send in your lens and camera.
Your D7000 has the ability to fine tune the camera to the lens, its called "AF Fine Tune" and can be found in your menu. It can have the focus fine tuned for up to 12 spcific lenses and not affect any other lens.
Feb 10, 2012 11:11:04 #
Florida Shooter
Loc: Lake Worth, FL
Thanks, I am aware of the fine tuning and I have tried it but I still have the problem. A friend who owned a camera store thinks the contacts are not lining up properly.
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