It seems like ML has 4 different focus stepping increments where as the PTP arduino protocol has only 3.
Regardless;
Does anybody know the relationship between them. As in how many small steps are there in one big step.
Whether they differ between cameras (which I guess they shouldn't as it's to do with the lenses not the camera),
I am particularly interested in 550D (as that is what I own).
It has 3 - exactly the ones from PTP.
The relationship is not known, but you can try to find it.
That first part actually helps because I was confused.
But now the challenge begins for me. :P
When I eventually find them I will post them here.