Sirius Glass
Subscriber
trouble to accurately focus is one of the most frequent complaints with the Hasselblad System. I had the same issue and tried a few screens. The one that worked best for me was the split screen accurate. I don't think brightness is so much an issue but the split screen really helps.
Accurate focusing problems arise because the focusing screen in not in the correct position. That is easily remedied with a trip to a Hasselblad repairman.