Following my post about replacing my Canon 1D Mark II which you can read here I’ve gone ahead and purchased another Canon 7D!
I’ve just finished giving it a check over and testing it all works correctly. As part of that I’ve set the Auto Focus Micro Adjustment for my Sigma 300 f/2.8 and my Canon 100-400 L IS.
If you’ve not heard of AF micro adjustments before, it is a custom function on Canon’s newer bodies that allows you to set a compensation for the auto focus. Using a scale of -20 to +20 you can correct any slight front or rear focus a particular lens has. If it is outside this correction scale you will need to have the lens re-calibrated.
Out of interest, I decided to redo my other Canon 7D and compare the correction figures to see if the AF system on both cameras would need the same amount of adjustment.
First up was the Sigma 300 f/2.8:
1st 7D body: correction of +14
2nd 7D body: correction of +15
Next, was the Canon 100-400 L IS at 400mm:
1st 7D body: correction of +1
2nd 7D body: correction of +3
Also fairly close!
With the results being close it would seem the majority, if not all, of the correction is on the lens rather than being a compensation for any variation in the AF system from body to body.
No real point to this, just thought I’d share!