[shuttertalk]

For the curious, the world's largest telephoto lens ever produced for civilian photographic purposes, the Zeiss AP Sonnar T* 4/1700 - has a focal length of 1700mm, and provides 21x magnification. It looks more like a sub or a torpedo to me, than a photographic instrument.

Never before has the world of photography seen such a lens. The ZEISS Apo Sonnar T* 4/1700 was developed by Carl Zeiss for a customer with very high demands and a special interest in long distance wildlife photography. To achieve the highest possible image quality, the customer decided on the Hasselblad 203FE 6x6cm medium format camera and ZEISS lenses as the best combination for his special needs.

This just amazing - I'm speculating that it must be vehicle mounted, since there's no possible way a human could carry it around. Plus, being fixed focal length, the user would need to move their position to adjust the framing...

The design of the ZEISS Apo Sonnar T* 4/1700 required new lens assembly techniques and quality assurance methods never before applied in photo lens production – even by Carl Zeiss' normally high standards. The finished lens weighs a staggering 256 kg (564 lbs.), placing unique demands on the focusing mechanisms. To address this issue, Carl Zeiss developed a totally new way of operating a telephoto lens, including servo controlled aiming and focusing systems like those used in large telescopes and similar instruments for astronomical scientists.

http://www.dcviews.com/press/Zeiss-Sonnar-4-1700.htm
http://www.engadget.com/2006/09/13/carl-...hoto-lens/

[NT73]

Of course if you could afford the lens, then you could afford the servants to carry it for you.
I used to manage 30kg fairly regularly in a day but 256kg?

[matthew]

I guess size is still important...

This lens is for a 6x6 hasselblad; from what I see it works out to about a 800-1000mm equivalent for 35mm photography. To put it into DSLR terms, I could do it for a mere $8529.98 (plus tax) with my Olympus. That would get an 840mm equivalent f4. My local store will order a Canon EF 600mm f/4L IS for $9700, which would be great on one of their 1.3x crop cameras; throw a 1.4TC on the Nikon AF-S 400mm f/2.8D and you're at f/4 and 840mm for $8630. (The 400mm is on sale, $300 off.)

Needless to say, the quality and demands of a 6x6 MF camera is far greater than that produced by any existing small format camera, although that may not always be the case. And the engineering and design challenges are certainly unique. But, if you're just looking for the reach, it's not unreachable.