These are very rare lenses, If fact, they are unique. It is an 8-1/4-inch clear aperture double-lens achromat, f-30. These lenses were designed to look at the Sun with hydrogen-alpha Solar filters. They can also be used to look at planets, the Moon, and other deep-space objects, without filters. They have antireflection coatings. The lenses were never used.Two lenses are available. This sale is for one lens only.About 20 years ago I had these matching lenses made for a retirement project. I intended to use them as binoculars. The views of the planets and Moon would be fantastic. I had planned to fold the light-path using optical flats to make the tube-length shorter. I will include the Zerodur flats with each lens at no extra cost.
Unfortunately, at 92 and with a bad heart, I know I will never complete this project.
Filed under: Eyepieces & Accessories