Reikan Focal peculiarities

I have tried to MFA my old Canon 50mm 1.8 Mk 1 various times using Focal and every time it gave me silly results.
Manual attempts at MFA would give me results of about -1 to -2, Focal gives me -11 to -14.
I have made many shots at -2 and I have proven that is correct at all apertures so it bugged me as to why Focal calculated it incorrectly.

I know that most Canon 50mm lenses have inconsistent focus but this wasn't responsible for the strange results, neither does the lens show any focus shift at different apertures.

I reasoned that Focal must work by comparing each shot by contrast and the one with the best contrast is the best focused. Like all wide aperture lenses my 50mm has a fair amount of flare causing low contrast at full aperture so I needed a way of reducing the flare during the test. Ideally I wanted to stop the lens down to about f2.8 but of course that isn't possible because focusing is always done at full aperture.

I decided to make my own false aperture to fit into the front recess of the lens and calculated (guessed) that an opening of about 18mm was required to simulate f2.8. So I cut a small circle of black card 40mm in diameter with a central hole of 18mm, the results were quite amazing.

First, a screenshot of focal after MFA with normal lens

PM on its way.

Both of your images display "photo no longer available" for some reason.

I purchased FoCal Pro a couple of years ago and to be honest I'm not impressed.

I find that the old method of a v shape of AA batteries does the job just as well, or one of those cheap little card thingies that are available. I find Reikan FoCal to be inconsistent to say the least. The same test performed multiple times will give widely varying results to the point of total confusion. This conclusion comes from use with my EOS 5D mkii, EOS 7d mkii, EOS 5DS.

I also have an historic issue with FoCAL AFMA on my EOS 1DX. Reikan Support has told me (July 2017) that my issue would be sorted with the next software update. It wasn't.

I am not definitively saying that the software has a compatibility issue with my camera as I just don't know; it may well be a fault on my camera; however I can definitively say that FoCal support is not interested in helping out.

oingyboingybob wrote in post #18543804
Both of your images display "photo no longer available" for some reason.

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Sorry about that, somehow they got deleted and I no longer have the originals.
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I find that the old method of a v shape of AA batteries does the job just as well, or one of those cheap little card thingies that are available.

Whilst I don't agree with the battery method, I do agree that a manual test with a good target will give perfect results although it can take a bit more time to carry out.
My original tests were carried out with Focal plus and it didn't allow me to stop the lens down. I have since upgraded to focal pro which does allow stop down testing and whilst it helps it still is not perfect and not as reliable as a properly performed manual test with my home made target.

Hi Ramon,
I experience the same issue of the other guy that asked you to PM him.
I appreciate if you can PM me as well (new guy here, so cannot PM).
I'll then I'll delete this message to keep this thread clean.
Thanks!