henry link said:CDK,
Thanks for your first reply. Sorry to pester you again, but did the Zeiss staff say why their Pechan prism has higher than normal light transmission?
Henry
Henry.
I see that Andy has already answered your question, it is down to the special layers on the mirror surface, apparently something which has been known for a few years. However the Abbe Konig prism still has a higher light transmission than the Pechan, but apparently the transmission figures between one manufacturers use of Pechan versus another's use is quite different.
CDK