Archive note: this is a historical account of a rare custom lens. The reported price is not a current sale price, and the old “world’s most expensive” superlative is not asserted today.
Leica APO-Telyt-R 1600mm f/5.6
Contemporaneous photography coverage reported that Leica made this unusually large 1600mm f/5.6 lens for Sheikh Saud Bin Mohammed Al-Thani of Qatar. Reports gave the commission’s cost as 16 million Hong Kong dollars, then equivalent to just over US$2 million. The lens was a custom build rather than a regular retail product; see Popular Photography’s 2012 report.
The images below show the lens and its scale. The source article reported a prototype at Leica’s showroom at the time; this archive does not establish where it is now.


