Go Back   Steve's Digicams Forums > Digital SLR and Interchangeable Lens Cameras > Canon Lenses

Reply
 
Thread Tools Search this Thread
Old Sep 27, 2010, 8:41 AM   #1
Junior Member
 
Join Date: Sep 2010
Posts: 14
Default Unusual vignetting/shadows in the corner problem on my EF-S 15-85mm lens

Hi,

I purchased a new EF-S 15-85mm lens three weeks ago and I am seeing some weird probplems with it.

I am experiencing the assymetrical vignetting problem that i have seen other people mentioning. I.e. in my example, top right corner, vignetting is strongest followed by bottom right corner. It can be reduced if I stop down to f7.1 and then whatever is left with DPP or similiar software.

Now to the weird thing. Yesterday, I tried the camera with 15mm focal length stopped down to f11-f22. The vignetting is back! However, now it is pronounced in a completely diferent way. Instead of light gray to dark gray color, it now has a blue tint to it, and while the area is smaller, the intensity is much stronger/sharper being completely black as closer you get inside the corner. Again this is only visible in the top and bottom right corner, and top right corner being the worst. You don't see it in the bottom right corner until aperture is stopped down to f16 and get intensified when you stop down more. At all other focal lengths, including 16mm and 85mm, I do not see this phenomena at all.

So anybody experienced anything like this on any lens? What is the cause of this? Espeically why does it have a blue tint?

I am not using any filters or hood. I have tried indoors and outdoors with different ISO settings, shutter settings etc.

I do not have a picture for the moment. But I will upload one later today. A picture tells so much more.
Shompis is offline   Reply With Quote
Sponsored Links
Old Sep 27, 2010, 8:51 AM   #2
Senior Member
 
TCav's Avatar
 
Join Date: Sep 2005
Location: Washington, DC, Metro Area, Maryland
Posts: 13,572
Default

If it doesn't happen with any other lens, and it's brand new, exchange it for another. If it's not new, talk to Canon about a repair.
__________________
  • The lens is the thing.
  • 'Full Frame' is the new 'Medium Format'.
  • "One good test is worth a thousand expert opinions." - Tex Johnston, Boeing 707 test pilot.
TCav is offline   Reply With Quote
Old Sep 27, 2010, 9:51 AM   #3
Junior Member
 
Join Date: Sep 2010
Posts: 14
Default

Thanks for the reply!

It is my only lens, so I do not have anything else to compare with, especially at the focal length 15mm where I see this issue. I will try to exchange it for a new one, but I am afraid I can't as it is three weeks ago I bought it.
Shompis is offline   Reply With Quote
Old Sep 27, 2010, 12:07 PM   #4
Senior Member
 
TCav's Avatar
 
Join Date: Sep 2005
Location: Washington, DC, Metro Area, Maryland
Posts: 13,572
Default

Is there another camera store you can go to, so you can try out other lenses to see if they do the same thing?

JOOC, can you see these defects in the viewfinder, or do they only show up in photos?
__________________
  • The lens is the thing.
  • 'Full Frame' is the new 'Medium Format'.
  • "One good test is worth a thousand expert opinions." - Tex Johnston, Boeing 707 test pilot.
TCav is offline   Reply With Quote
Old Sep 27, 2010, 1:55 PM   #5
Junior Member
 
Join Date: Sep 2010
Posts: 14
Default

Hi,

I called them. They will not replace it with a new one. However they will help me try my camera with another lens , and the faulty lens on a different body just to be sure the problem is in the lens and not the camera. I would like to get a replacement though as I think three weeks is more or less brand new.

I do not see the defects in the viewfinder.

Shompis is offline   Reply With Quote
Old Sep 27, 2010, 2:23 PM   #6
Senior Member
 
TCav's Avatar
 
Join Date: Sep 2005
Location: Washington, DC, Metro Area, Maryland
Posts: 13,572
Default

Quote:
Originally Posted by Shompis View Post
I do not see the defects in the viewfinder.
That makes diagnosing it a little more complicated.

I suggest you spend some time figuring out the exact conditions (camera and scene) under which the problems occur, so that when you show up, you can reproduce the problem. Otherwise, it will be just like when you take your car to the dealer complaining about a noise that they don't hear.
__________________
  • The lens is the thing.
  • 'Full Frame' is the new 'Medium Format'.
  • "One good test is worth a thousand expert opinions." - Tex Johnston, Boeing 707 test pilot.
TCav is offline   Reply With Quote
Old Sep 27, 2010, 2:31 PM   #7
Junior Member
 
Join Date: Sep 2010
Posts: 14
Default

Well everytime I had the camera with these settings (15mm focal length, f22) I have seen the problem. I saw it for the first time yesterday because that was the first time I tried it stopped down to f22. At any other focal lengths, it's gone.
Shompis is offline   Reply With Quote
Old Sep 27, 2010, 3:50 PM   #8
Junior Member
 
Join Date: Sep 2010
Posts: 14
Default

New findings!

If I manual focus and focus to "macro" i.e. nearest, I start to see these shadows in all corners! I can now see it in 17mm aswell!

Worst scenario: focus to macro/nearest, 15mm focal length and f22.

sample,

Shompis is offline   Reply With Quote
Old Sep 27, 2010, 4:09 PM   #9
Senior Member
 
Ordo's Avatar
 
Join Date: Jul 2009
Location: BsAs
Posts: 3,452
Default

What do you mean by "macro/nearest"? No macro in that lens and your pick is not shot at the nearest focal distance at all.
BTW: what's your camera?
Ordo is offline   Reply With Quote
Old Sep 27, 2010, 4:17 PM   #10
Junior Member
 
Join Date: Sep 2010
Posts: 14
Default

Canon EOS 50D.

Sorry. I ment closest focus distane when I said macro/nearest. On the usm focus ring it is indicated as "macro" and I believe it is 0.3 meters.

How can you see it is not shot at closest focal distance? I turned the focus ring to the left as much as I could to where it says macro.
Shompis is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 12:30 AM.