Originally Posted by RedLion
No. It's exactly the same. It's just as easy to focus the 0.58 as it is the 0.72. In fact, I think I even like the looks of my 50mm frame lines on the 0.58 better. Theoretical focusing "accuracy", on the other hand, may be slightly different between the types.
As an eyeglass wearer, anything wider than 50mm was a bit distracting on my 0.72 as I was always tempted to either try to press my eyeglasses harder into the eyepiece to try and see both sides of the frame lines OR i would move my head back and forth a bit to see each side sequentially. With the 0.58 this is no longer a problem.
I'd have to conclude that for myself as an eyeglass wearer, the 0.58 is ideal IF you are mainly using lenses wider than 50mm. (my favorite focal length is 35mm) IF you're mostly at 50mm, then 0.72 is fine.
Thanks for your clarification ! I have to agree with you about the hassle seeing the wider than 50mm frame lines with eyeglass on 0.72 finder. This is why i sold my M6 .72 classic and got myself a M6 .58 TTL since i'm an eyeglass wearer and i use my cron 35 a lot.
I have seen many people are capable to nail the focus precisely with nocti 50 f1 wide open on .58 finder, so there is nothing to worry about.