AF Microadjustment

[AlanP]

Has anyone had any problems with the Microfocus adjustment point drifting dependent on the temperature?

This happens on my 600mm lens alot.

[Bill-Emmett]

How do you tell the problem is temperature related.  Micro adjustment is a electroinic adjustment relating to the lens, and the photo sensor.  Where are you seeing the change, in the micro adjustment section of the cameras menu?  Living in Louisiana, in deep humidity, and high temperatures daily I've not seen this with any of my lenses.  I use FoCal Pro for my adjustments, on a Canon 50D.  How are you checking your lenses for front/back focus?

Bill

[AlanP]

At times when it gets warmer outside I must reduce the AF microadjust as much as 4-5 in order to keep the center of my DOF

"Depth of field" in the same place. When cooler weather come in I have to adjust it back out by the same amount. The actual number setting doesn't drift It stays set where you adjust it too.

[Bill-Emmett]

I've never noticed any changes after I set a lens. Of course in Louisiana, we don't experience extreme temperature changes from hot to cold.