« on: March 15, 2013, 01:01:09 AM »
Please comment. I just bought a used 1DsMk3 and saw a consistent "back focus" -- that is, with a few different lenses images appeared to be focused on a point a little behind the intended point of focus... best I could remember, of course, where I asked for focus. Not 100% but a lot of images showed this.
I own Reikan FoCal and made some time today to test as the sun went toward setting (we rarely have low winds here...) and got through the following lenses: 24-70 v2 (at 70); 70-200 v2 (at 200); and the Sigma 35mm f1.4. The last test was asked to soldier on through what I know was too dim a light. Yes, I know it's best to do this with sunlight.
The results were all positive numbers like 4, 7, and 5, respectively.
So are positive numbers in FoCal consistent with my description/observation of back focus?
I do plan to redo this under better conditions. Hard to get all the factors -- including time -- together. I did like having the test run automatically, as my 5DMk3 has the annoying SDK failings that Reikan tells us are NOT in the 6D camera software.