I've been using FoCal and it does what it's advertised to do. However, this lens fine tuning has so many variables and factors that it's really not very realistic. For example, if you need a perfect target that's perfectly illuminated to get accurate, repeatable results...what do you think your AF system is doing during 'real world' shooting? It's probably all over the map.

So I've resorted to using FoCal to get a very general idea of how my camera and lenses are performing (discovering sharpest apertures, best AF points in the camera, etc). However, unless things are dramatically skewed, I now keep AF fine tune off.

-Alex Rosen
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