Diagonal Minor axis?

I was sent a program called newtwin for designing reflectors. one of the parameters says diagonal mirror axis 1.5 ? can any one tell me what this means.

program source.

www.dalekeller.net/atm/newtonians/newtsoft/newtsoft.htm

Regards Paul

Um... that's MINOR axis (not mirror axis!)

The diagonal secondary mirror in a Newt is eliptical and thus has two axies - a long and a short axis. The short one is referred to as the Minor Axis and discribes the diameter of the circle the secondary mirror appears to form when viewed at 45degrees.

Phil.

Thanks Philip.