500mm F4

[Nelson]

http://www.leboncoin.fr/vi/99037910.htm?ca=12_s

have you already seen one of those ?

[ManualFocus-G]

That's huge, great find! I reckon the only person strong enough to lift that would be Martinsmith99 (probably from all the ironing )

[CarbonR]

Flor27 (he doesn't post any more here) has tried a Librascope 500/3.92, but I didn't seen this one. I would not have the 400/4 and the 500/4.5, I'd buy this one to try it (even if 500/4 is likely to be usable with a cata lens due to the thin dof)