How is pressing the Knob working? Fine or do you have there some quality loss?

Oh yeah, I should cover that, too.

I had to mod the knob. I had to shorten its collar so that it didn't interfere with my white diffuser, and I had to shorten its overall depth so that it doesn't stick out quite as far. Also, I had to dremel the collar so that it was thinner and didn't interfere with the hole in the lens (otherwise it tended to rub against the edge of the hole in the lens).



But now, it works perfectly, doesn't interfere with anything, and has the proper "feel" to it. And the shorter depth is actually really neat, I like it a lot.

The only trick is that since I don't have a 2A shaft, I am heavily dependent upon the collar to hold the rubber O-ring. So I had to be extremely careful not to shorten the collar too much and not to thin out its sides too much, otherwise the O-ring wouldn't work.