I'm convinced it's a secondary issue. I'm sure it's not square. It's too easy to adjust everything else to make it look right.
Pete's probably reading this on his iPad but I'm sorry I respotted the primary now. It was working ok with the original white dot. Those stupid red triangles should be white not red, they are too dark. It has to pointed to bright sky for it to work now but I'll try it on the light box flat out tomorrow and see
