----------------------------------- turlea.cosmin 20 Dec 2021 02:56 Ocular RDP (Red's Double Plossl) ----------------------------------- Salutare ATM-isti, Surfand pe internet,am dat de un tip care spune si face oculare de camp larg din obiective de binoclu. A incercat careva sa faca?Greu nu pare din ce spune.Tinand cont ca a venit vremea rea,parca m as apuca de un proiect nou.Las mai jos instructiunile,poate mai sunt doritori. " Making high-quality, well-corrected 2” eyepieces at home. Use old binocular objectives in pairs. Face each pair toward each other as closely as possible, as shown in the diagram. Each pair can be any size from 30mm to 60mm — just experiment and see what works best. I tape eyepieces together temporarily while I try them out, and then epoxy them together if I like them. Sometimes they remain taped together, which I am not worried about, as I am in my 70s and they will outlast me. For the eyepiece barrels, the so-called 2” tubing actually needs to be a little smaller than that size, to go in a 2” focuser. The best tubing I have found is some polished aluminum motorcycle intercooler tubing, about 50mm diameter, on eBay. As I said, use four binocular objectives, arranged as in the diagram. Position them all as closely together as you can. Four 35mm binocular achromats, or two 30mm and two 35mm, assembled this way, will usually yield an eyepiece of from 36mm to 39mm focal length. Apparent field of view then comes to 50° to 55°, depending on the focal length. Four 40mm lenses, or two 35mm and two 40mm, make an eyepiece of about 40 to 43mm focal length, with field of view often well over 60°. This may be my favorite combination for use on my 14” reflector. Two 40mm and two 50mm binocular lenses usually give a focal length of 45 to 48mm, with Apparent Field of View about 55 to 60°, sometimes more. Four 50mm binocular lenses yield a focal length of 50 to 55mm, AFOV about 50 to 55°. Cer senin!