Well, here's a picture of the 11" objective I made for my scope.
It's a doublet with a slight air gap between the elements. The front element is made from O'hare's famous CPI1P (Cast Pig Iron One Pour), the rear element is Shot HD3/8PW (Home Depot 3/8" Ply Wood).
I can detect no spherical abberation of any kind, including spherochromatism. There are NO color crossings as there is no longitudinal color error from the deep dark red to radio frequency blue. Fifth order and all other abberations are zero. It's not sensitive to wedge and very tolerant of de-centering of the elements.
It was cheap to make (about 26 bucks) and NOT imported from China.
Jeff
It's a doublet with a slight air gap between the elements. The front element is made from O'hare's famous CPI1P (Cast Pig Iron One Pour), the rear element is Shot HD3/8PW (Home Depot 3/8" Ply Wood).
I can detect no spherical abberation of any kind, including spherochromatism. There are NO color crossings as there is no longitudinal color error from the deep dark red to radio frequency blue. Fifth order and all other abberations are zero. It's not sensitive to wedge and very tolerant of de-centering of the elements.
It was cheap to make (about 26 bucks) and NOT imported from China.
Jeff
Attached Image:
"Don't sweat the petty things and don't pet the sweaty things" 8O
