I notice that I use the microprism donut on my MF cameras more often than I use the split-image prism in the center. I would probably like a focusing screen that ditches the split-image prism and fills in the space with more micro-prism. But then I was thinking that it might actually be pretty cool to have a focusing screen that was completely micro-prism. Then only objects that were in focus would be clear and everything else would be all well, micro-prism'd. Has there ever been such a focusing screen available?