AF issues with 600 and 400 MK III

Dholai

EOS T7i
Feb 5, 2014
57
4
Please tell me what am I doing wrong.
I just upgraded from the MK II versions of these (600F4 and 400 F2.8)
Both the lenses on 1DxMKII will not AF at all when changing focusing from a near to a far point. e.g. If I am focused at 20 ft-trying to focus at 200 ft or at infinity does not work- the camera will simply not focus. Even rotating the barrel manually does not do any good.
OTOH- if I go from, say, 20-50-100-200 ft to infinity - it will focus but that too is inconsistent. sometimes no matter what I do- nothing , I repeat, nothing at any distance will be in focus.
I keep the AF-ON or the shutter half pushed. Makes no difference.
Even on manual focus- rotating the focusing barrel does not change focus promptly- it rotates on and on- reminds me of 85 mm 1.2L

Never had these issues with the old lenses.
Called Canon - could not give me a solution. Tried their recommendations- no result.
I am sure the fault lies with me. What am I doing wrong- what am I expecting wrong?

Please help. Thanks.
 

ethanz

1DX II
Apr 12, 2016
991
247
ethanzentz.com
I don't remember where you live, but maybe you could get a loaner from CPS and see if that exhibits the same behavior as your lens?
 

Dholai

EOS T7i
Feb 5, 2014
57
4
. In Atlanta Ethan. Thinking to return and exchange them. Just curious to hear if anybody else had the same issues
 

Dholai

EOS T7i
Feb 5, 2014
57
4
Based on another tech savvy photographer's suggestion- I did reset all functions in both cameras and now- both lenses work like a charm. All issues solved. But that brings up the million dollar question- what setting caused the fault and will it come back when I reload my settings?
I guess I just have to try and see
Any idea anybody ? Please ??
 

Viggo

EOS 5D SR
Dec 13, 2010
4,028
558
Only thing I can think of is that function where you can tell the camera to not continue to try and focus if focus can’t be achieved. You can either tell it to keep trying or simply stop.
 
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