BirdForum is the net's largest birding community dedicated to wild birds and birding, and is absolutely FREE!

Register for an account to take part in lively discussions in the forum, post your pictures in the gallery and more.

Reply to thread

Message: <blockquote data-quote="Binastro" data-source="post: 3548230" data-attributes="member: 111403">Hi Maico,Post 25D.Bonaccini 1992  Design of f/0.9 Schmidt Maksutov cameras for 8m class telescope.This is a 300mm.There are in fact many Schmidts around f/1.Schmidt camera - Wiki. gives details.12 Baker Nunn cameras were used for tracking satellites from late 1950s to mid 1970s.  375mm approx. focal length f/0.75.3.5 tons each.I have seen a refracting 14inch f/0.75 lens, weighing about 350lbs. With an 18 inch or slightly larger front element. This was used for tracking. Mounted on the back of a truck.The 12inch f/2.5 Aero Ektars of which I had about 3 or 4 were very heavy. I donated them to museums.I also had an 8inch f/1.5 Aero Ektar, extremely heavy, which went to lens heaven about 1990 and the TTH 8inch f/1.4. A professional photographer used his 8inch f/1.4 TTH on 5x4 inch film for industrial photography. Also the 180mm f/1.3 Zoomar. I never did see a 240mm f/1.2 Zoomatar for 70mm format. They had matched teleconverters. I had the 2x teleconverter.There are also very large fast Russian lenses.P.S. The Wray 36inch f/4 lenses are heavier than 16lbs. I had a job lifting them. The internal shutters could take ones hand off if one were silly enough to put a hand through the lens. 9 inch front elements. Good quality glass.</blockquote>