Bassat wrote in post #18676600
Be advised that for best results, Canon suggests using MFA on each camera/lens combination, at the distance you will be shooting, and in the light you will be shooting in. That is (would be, if I ever did it) incredibly time-consuming.
Not always as time consuming as you might think, especially for primes. Now if you use Sigma's hub to calibrate their lenses, there are 4 different settings for primes, and 16 settings for zooms which you need to calibrate, and adjacent settings can interact with each other. And of course you can then only use that lens with the camera it's optimised for.
In my experience with Canon's in body adjustments, while you may not be completely optimising a lens, experimenting with adjustments in normal shooting, especially with a lens you are very familiar with, can produce significant improvement over its non calibrated state. This is very useful for lenses that are clearly soft at the focal plane due to front or back focusing. It still takes attention to detail, and it does still take time and effort, but the results are worth it.
My EF 35mm f/2 IS USM and my EF 70-200 f/4L IS USM were both calibrated by me on my 7D2 over time though experimentation to correct softness and are now both significantly sharper as well as more consistent. My Sigma 18-35 mm f/1.8 worked almost perfectly on my Canon 60D but was so way off, especially at f/1.8, on my 7D2 that I was seriously considering selling it. With a little experimentation, it went from unusable to excellent in that camera.