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Here is the comparison of the four masks. These crops should be 100% size when you click on it, if you know what I mean.
ISO 6400, 125 of a second I think, for no particular reason other then it filled the live view screen at ten times zoom but is otherwise arbitrary.
This time I made three stars of various magnitude. These stars are about 10 meters away from the lens.
I'm sure you will find this satisfying if unscientific. The Bahtinov mask is IMO far superior to a simple Y mask by a considerable margin.
Go with a mask recommended Bahtinov factor 150 if you can, if not the 100 and 50 are still much better then the Y mask as you can see.
Ultimately you don't even need the calculator. Make a mask with the same diameter as your clear aperture, make the slats as thin and numerous as practical. Use your judgement as to how wide the "T" part should be the separates the sections of the mask, just wide enough to support the slats is all that is needed. I went with 4mm on my little masks, I may make them a little thinner on a final version.
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