There's always a wealth of knowledge here on RFF, and I hope I can receive some guidance. I have a Hasselblad PME90 meter prism, which I use with the plain acute matte screen. The combination works perfectly, but my tired old eyes would love to use my other split-image/microprism screen, also acute matte, for its superior focusing. However, Hasselblad recommends against using that screen with the PME90, since the focusing aids interfere with with the spot meter's proper functioning (and of course I use the spot meter most of the time). They do not offer any factor by which I could adjust my readings. Now, I could easily do some trial and error metering with the average and spot meters to come up with a correction, but would that correction be linear across all readings? And if there is an accurate correction factor available, does anyone have that info? I've searched the internet 'til I'm bleary-eyed, but without success. All suggestions are welcome!
