I spent some time yesterday and today rechecking two lenses that I had some question about.

The new version worked fine. It seemed to converge faster on an answer, it definitely (and I do not quite know why) yielded a much steeper curver in all cases, for a more defined "best".

Interestingly I checked 2 cameras and 2 lenses and came to the same number (+/- 1) that I had with the older version, which was a bit reassuring.

I also did a pretty careful live-view vs. AF test on the center, and cannot tell the difference between them.

One thing I also tried (which would work with the older one as well) was to save the actual images during a Aperture test. I then did a live view very careful focus of an spot on the ground, and turned off AF. With the full frame, I could test for focus shift to see how bad it was. I'd heard the 85/1.4G in particular was bad. It's a very nice, fast way to get a feel for that (the answer by the way was "not too bad". At about F2.8 it shifted back enough that the spot on which I was focused was at the very front of the focal range, i.e. blurred just in front of it, but as the DOF deepened I began to pick up focus in front and behind. But it definitely shifts the center of the focus back as the aperture goes to a higher F-stop. Something I need to keep in mind, aim more the front not the middle of the area of interest. The 70-200 (the other I tested, at the same 85mm) stayed nicely centered.


Linwood

Comments welcomed on pictures: Http://captivephotons.com