It is not the finder as much as the focus screen. Unless your issue is the fact your eyes do not accomodate well to the apparent distance of the viewfinder eyepiece, then a correction diopter on the eyepiece can aid your eye to better focus at the (about) 30-36" apparent distance
I find with all MF lenses I have slow down when getting the focusing spot on, shooting at f1.9 is even harder. I have the Prism Viewfinder and I do wish the eyepiece was larger, which I think is the cause of my mistakes.
It is not the finder as much as the focus screen. Unless your issue is the fact your eyes do not accomodate well to the apparent distance of the viewfinder eyepiece, then a correction diopter on the eyepiece can aid your eye to better focus at the (about) 30-36" apparent distance
I find with all MF lenses I have slow down when getting the focusing spot on, shooting at f1.9 is even harder. I have the Prism Viewfinder and I do wish the eyepiece was larger, which I think is the cause of my mistakes.
With my Hasselblad at f/2.8 I generally do not have an issue focussing, I think f/1.9 is barely has any DOF left. I might get a WLF for it and see how I get along. Do the WLF have a magnifying glass to help nail focus?
If you bought the finder used, check to make sure that someone else didn't previously install a correction diopter that isn't compatible with your eyes.
I usually find it easier (rather than harder) to focus a brighter lens with shallower depth of field.
The camera and the finder are fairly old - could the finder benefit from cleaning and service?
There were interchangeable focus screens available for that camera. Which one do you have installed?
I bought it from Keh, and I believe they generally service their equipment before selling it. I will check which focus screen is installed when I'm back home after work.
Where would a correction diopter be installed? Is it very obvious by the eye piece?
If you bought the finder used, check to make sure that someone else didn't previously install a correction diopter that isn't compatible with your eyes.
I usually find it easier (rather than harder) to focus a brighter lens with shallower depth of field.
The camera and the finder are fairly old - could the finder benefit from cleaning and service?
There were interchangeable focus screens available for that camera. Which one do you have installed?
I bought it from Keh, and I believe they generally service their equipment before selling it. I will check which focus screen is installed when I'm back home after work.
Where would a correction diopter be installed? Is it very obvious by the eye piece?
I have the 80mm f/1.9 as well. It's not easy to focus accurately. You might try a focusing screen with an aid - like a split-image rangefinder or microprism spot. I'm not keen on the 45 degree sirf with mp collar - which is common on the original M645. I think the horizontal sirf is better. It's also possible to adjust the screen as it sits on 3 cross headed screws. Somebody may have already done this for you! Or the screen may have gone out of adjustment.
I have the 80mm f/1.9 as well. It's not easy to focus accurately. You might try a focusing screen with an aid - like a split-image rangefinder or microprism spot.
I have the split screen AE prism viewfinder. With a circle in the middle and a line going through it. Whatever is on that line when out of focus is split.
However when you say split-image rangefinder...do you mean something like I would expect in a Leica? If that's the case what kind of viewfinder is that?