Irrational Fear: 1/500 and 1/1000?

[Pál_K]

The cost of a frame is relatively inexpensive, so live dangerously: if one of your photos is f/11 at 1/125, make a second shot at f/4, 1/1000 and see what you get. You might even like the reduced depth of field.

 

[Sarcophilus Harrisii]

And because the slit is narrow, an amount of change in slit width that would be, say, 10% of the slit width at 1/125, thus insignificant, becomes 40% change over the travel of the slit at 1/1000, which is noticeable.

I'm like the OP (although I possess no Leicas), except that I know for a fact that some fast speeds taper a bit. Nbd for me as I usually want to stop down anyway.

This, exactly—which is why 1/1000 and to a lesser extent 1/500 may be problematic, whilst all other speeds could be within tolerance. Having recently serviced a IIIf RD, one thing I liked about the quality of the mechanism was the separate adjustments for the 1/500-1/50 slits, plus a dedicated one just for 1/1000. Unlike some other vintage fp shutter set ups, you get to have your cake and eat it: don't have to settle for least worst accuracy across all the various speeds and perfection for none. Even a Contax fan like myself acknowledges Leitz got that right.