Posted By David Simons
You might try Surplus Shed (dot com)
Send an email, and they say they can get a lense made. They quoted me one once, although I eventually got it cheaper through other channels.
[/SIZE][/COLOR]Keith Lawson said:
Ok, before you start telling me I'm in the wrong forum, let me explain There are some glass pushers out there that have made a lot of mirrors but have made lenses also. I'm in need of a custom made barlow for a planetary Newtonian project. The final instrument will be 10" F/15. This is a purely visual lunar/planetary instrument. The primary will be F/6. The barlow will be ahead of the diagonal and the secondary obstruction will be only 18% including the housing for the lens/diagonal combination.
The barlow is a flint forward design. At final focus the 100% illuminated field will be 1/2 degree and the star images will be diffraction limited to a 1/4 degree field of view. The glass components for the barlow are BK7/N-SF5.
Any mirror makers out there that are small lens makers too?