The Nokton 40 brings up the 50 frame lines in its unmodified form. It is easy to file down the bayonet "claw" to bring up the 35 frame, which I prefer to use with this lens.
Does it matter? Well, it depends how tight you want to frame. If you shoot slide-film, it is more important than with bl/w - color negative as you have whatever crop you choose on the image. With color negative or black/white you can crop in the printing stage (we are talking print making, not Photo shop or scanning images where you have more leeway in cropping and adjusting).