Now doing my 85mm f/1.8 and 50mm f/1.8 II.
Lense | Focal Length | Suggested MA | Fit Quality | Age/condition |
17-55 f/2.8 EF-S IS USM | 17 | -2 | Excellent | 2y/Excellent |
17-55 f/2.8 EF-S IS USM | 30 | 4 | Good | 2y/Excellent |
17-55 f/2.8 EF-S IS USM | 55 | -2 | Excellent | 2y/Excellent |
100mm f/2.8 EF USM Macro | 100 | -1 | Not Acceptable | ??/Good |
85 f/1.8 EF USM | 85 | -12 | Excellent | ??/Good |
50mm f/1.8 II EF | 50 | -12 | Good | 5y/Good |
70-200 f/4.0L EF IS USM | 70 | 0 | Excellent | New/Excellent |
70-200 f/4.0L EF IS USM | 120 | 0 | Excellent | New/Excellent |
70-200 f/4.0L EF IS USM | 200 | 1/2 | Good | New/Excellent |
Did the 85mm and 50mm now with very different results. My batteries are flat, so that might have affected results (should not, but who knows). Will redo those and also my telezoom when battery is charged.
Enclosing screenshots of new calibrations.
The 85mm seems to be very consistent (large aperture, hits same focus every time, seems to have a significant predictable offset -> perfect candidate for MFA).
The 50mm is less consistent, but I am surprised at how consistent it was (a lot more bell-shaped than the considerably more expensive, although more specialized 100mm macro). When using this lense tethered, I have been shocked by how large the minimum step of the AF motor was, thinking that indicated coarse AF performance.
I was hoping to repeat the same test at large distances. FoCal supposedly can do this thing against any target that is flat and contains sufficient high-frequency contrast. 3.5 meter and 50 meter measurements should do for general purpose photography, right? If results are
similar@3.5m and 50m, then I suppose that they are global. If they are very different, then I'll either ignore them, average them, or do more detailed testing.
I am very confident that I would never do this much testing if I had to do it manually (30-50 shots at 1/3 focal lengths for primes/zoom lenses, hopefully 2 distances, repeated at least 2 times), and judging from the progress of the analysis, errors/noise are sufficiently large that I could have ended up doing things worse had I settled for smaller sample sets.
-h