Fluorescent lighting and auto focus

Sinopa · 12 Dec 2009 at 04:22

Does anyone know if fluorescent lighting is known to cause auto focus problems.
My Canon 5DMK2 certainly seems to struggle under fluorescent light.

robertgilbert86 · 12 Dec 2009 at 09:15

Can't say I've noticed anything like that.

RussD · 12 Dec 2009 at 12:39

If the light is low then it will cause auto focus probs on any camera.
Use RAW and a small torch. Shine torch on object/person whatever, focus on it, turn off torch and take shot. It is called, pre-focus.

Sinopa · 12 Dec 2009 at 15:48

I don't think it was a low light problem. I was directly under a pair of 5ft fluorescent tubes and the exposure was 1/160 f1.4 @ ISO400.

I wasn't taking a serious photograph, I was just trying to demonstrate the 5Dmk2's micro-focus adjustment feature to a friend.

It was a nice, easy to focus on, high contrast subject. I was using a good tripod and timer shutter release. I was getting random results suggesting anywhere between -5 and +2 adjustment.

The lens used was my Canon 50mm f1.4 USM which I have previous, in good daylight, easily determinded needed a +2 adjustment.

olv · 12 Dec 2009 at 15:57

The 5D II AF is just rubbish really. I really can't believe they thought it acceptable not to update it.

Sinopa · 12 Dec 2009 at 16:23

olv said:
The 5D II AF is just rubbish really. I really can't believe they thought it acceptable not to update it.

I would not go so far as saying rubbish but I have to say I find the AF to be the weakest point.

It does depend on the lens though. I can't seem to take an out of focus shot with my 70-200 f4L