For anyone doing this with anything more than a casual approach:
There is not a single table/chart calculator in the world which will substitute doing your own HF testing for each lens/body/back combo you own. There is variation in every lens mount, lens focus barrel, body/back/film mount and the sticky matter of what is "acceptably sharp".
Doing this tethered, e.g. to Capture One Pro makes life MUCH easier (since you can see sharp/not sharp instantly and compare two images instantly on a large monitor).
1) start off at a "good aperture" like f/8* and see what the sharpest image you can get is for infinity
2) stop down to your desired working aperture**
3) very slowly back off of infinity taking shots at the smallest increments possible until you detect a loss of sharpness that you find personally unacceptable
4) move towards infinity slightly to allow wiggle-room for slight changes over time and because of temperature
5) record the exact HF distance on your lens cap.
Alternatively you can purchase from a dealer who can do that with you in person as a service.
*if you don't know the sharpest aperture for your lens then you should test that first
**if you haven't tested to find your desired working aperture (balancing diffraction against sharpness)
***In Capture One Pro you can select the sharp image from step #2 and push "Enter" and that reference image will stay on the screen as you continue to shoot the comparison images - making it dead simple to compare the sharpness of each focus-distance to the reference image.
Doug Peterson
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Head of Technical Services, Capture Integration
Phase One, Leaf, Cambo, Canon, Apple, Profoto, Eizo & More
National: 877.217.9870 | Cell: 740.707.2183
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