Some finderscopes would be damaged by solar projection.
Thats becase the solar image at prime focus will be
projected onto the reticle of the eyepice. If the reticle is a
plastic crosshair (common) rather than a scribed glass disk, then
it could well melt.
Check your finderscope by removing the eyepiece. Sometimes the
crosshair is removable. If you can take the crosshair out, then
a finder may well make an adquate solar projection scope.
-ad
--- In OAFs@y..., r.prevost@h... wrote:
Just wondering about whether anyone knows if a finderscope can be
used
safely to project the image of the sun onto paper. Isn't a
finderscope like a tiny refractor? It should be able to project a
clear enough image of the sun to see sunspots.
What I don't know is if such a procedure would eventually damage a
finderscope or not. I guess it depends alot on the apeture of the
finderscope. One of my books "City Observing" ( Sky & Tel press )
says that inexpenive "refractors" 40mm to 60mm should present no
problem. Just be careful not to look through it though.
Later,
Rol
