: I have an old Leitz Wetzlar projection lens designed : for an episcope. It is f/6,3 6" and consists of four : elements mounted in a heavy steel cell. I have tested : it very briefly and was impressed of it's light gathering : power. Without any suitable mount, I could not check it : properly. : Has anyone some hints for a design; baffles,tube etc? : Thanks in advance. : :-) arne

Arne, I have a similar lens that was used for aerial l recon. of enemy during WW11. This too has a 4 element lens and works at F6.3. After I goteach lens polished and AR coated, I had the lens made up into an RFT refractor. While this gave crisp views of the Milky Way, the lens stills suffer from chromatic abberation. It now has been converted back into a phot lens for 4x5-inch format and because the ray tracing of the light path was done for the refractor design, you will have to do this regardless what you use the lens for. Well baffled and constructed, your Letiz lens will give you far better images than my old Aero Ektar! You may have to use a light to medium Yellow filter to help combat some C/abberation. A heavy lens they are, so a solid Alt/Az mount is called for.

As for a tube, get a local metal turner to machine some Alum. thick wall tubing. and attach 2.7" Astro Physics focuser. You will be able to use then, a Pentax 6x7cm medium format, or larger camera. 35mm will be toooo easy! Good luck Arne, let us know how you got on, Regards from Down Under JIM.

• Re: 6" refractor? - Dennis_Simmons/">Dennis Simmons - March 30, 1998 - 22:42 UTC