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100-400mm Problem

mogan
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p.1 #1 · 100-400mm Problem

Here's a mystery I have yet to solve...

My 1dsMkII takes perfect photos with my basic 24-70L lens. However, when I use the 100-400L, images are underexposed by about 2 stops.

I already sent the lens and camera to the factory for repair and it's still a problem.

Thoughts?

Jul 08, 2009 at 12:50 AM

KaaX
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p.1 #2 · 100-400mm Problem

Diaphragm problem in the lens...

Kaa

Jul 08, 2009 at 12:57 AM

EB-1
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p.1 #3 · 100-400mm Problem

Can you determine if it is an aperture problem or not? Does the diaphragm open completely when you look into it on the camera, and close when set to a smaller aperture? What are the camera readings for the 100-400 vs. a known, good lens?

EBH

Jul 08, 2009 at 12:58 AM

mogan
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p.1 #4 · 100-400mm Problem

I did some added playing with the camera/lens.

In manual mode once the light meter has been activated, I get different meter readings if the shutter putton is pushed halfway or not. It doesn't behave this way when using my 24-70. A meter reading is a meter reading regardless of what you do with the shutter button. Does this suggest anything about my problem?

Jul 09, 2009 at 02:11 AM

mogan
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p.1 #5 · 100-400mm Problem

Oy!

Just tried the body with a 600mm lens. Same problem as with the 100-400mm. Ideas?

Jul 09, 2009 at 05:19 PM


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