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Message: <blockquote data-quote="Binastro" data-source="post: 3531877" data-attributes="member: 111403">Re. post 28.There are or were actually much larger and more expensive camera lenses than the $2m Leica 1600mm f/5.6.There was a Leica lens for photographing across the Chanel. From memory about 3500mm FL and big.There is the 144 inch f/8 for 28 inch square film, now used for tracking asteroids to 1/50 arcsecond. I think designed by Baker.A 32 inch aperture refractive surveillance lens that appeared once in a Finnish magazine but went back into hiding.The Williamson Ross 6 inch f/5 survey lens weighs about 70 pounds? Cost about £85,000 in 1960s so cheap really. Unfortunately thorium glass.70 inch aperture big bird lenses. Resolve about 4 inches from 200 miles. Cost?  A lot.Various large Itek lenses and similar. Used at around 80,000 ft. Clearly shows golf balls on the greens.3 30cm Zeiss  binoculars on altazimuth mounts weighing perhaps a ton. 1940s? 11inch approx. Japanese binocular still maybe in a Japanese museum.APM 12 inch current binoculars, maybe around $300,000 dollars now? Without shelter, which costs extra.There are others.</blockquote>