The Canon FD 800 mm supe telephoto lens incorporates Canon-designed UD glass for improved definition, contrast and reduction of flare. In addition, certain mechanical improvements have been added that enhance operation and convenience. Since this super telephoto lens must be tripod pounted for good results, a click-stopped "one-touch" release lens revolving mechanism permits fast changes from horizontal to vertical format photography. Rotating knobs provide fast, precise focusing and a locking mechanism can be adjusted to provide varying degrees of friction in the focusing control system. SPECIFICATIONS Type: super telephoto Construction: 7 elements in 6 groups including special UD glass element Angle of view: 3 degrees 06 minutes Minimum Aperture: F/32 Closest Focusing Distance: 45ft Filter size: drop-in type 48mm with holder Lenshood: Built-in; extension hood EH-150 Length: 22 11/16 in Weight: 150 5/8 oz.