BTW, if you do opt for one of the Surplus Shed Jaegers objectives, don't use masking tape for spacing as Fred suggests. Use the metal-foil tape that HVAC techs use to make AC coil housings air-tight. You can cut tiny sections with scissors. I have some if anyone needs it. Another option is to oil-space them. This effectively eliminates two air-to-glass surfaces. Can be messy if you don't get the edges sealed completely. Never cement an achromat over about 5" aperture, as differential flexure will pop them apart or damage them. On 9/20/11, Chuck Hards <chuck.hards@gmail.com> wrote:
On 9/20/11, Steve Fisher <iotacass1@hotmail.com> wrote:
I'm thinkin 11" f/15 or longer would be nice. Perhaps the one in Orem will come available after I win the Lotto!
Steve, have you considered grinding and polishing your own large doublet? All the surfaces are spherical, so they are a snap to figure. Chasing down wedge is usually the only tedious part, and that can be avoided with care.