Hey everyone - I'm just wondering whether anyone could give me some pointers to construct my own 10x8 reflex hood for my Sinar. I do understand that a first surface mirror is mandatory for the reflex, though is there any other tips for angle/geometry or binocular sights that I need to know? I've become very frustrated with poor framing on my 10x8 portraits, so any advice in making my own will be greatly appreciated!

Have a great day!