DSLRUsers.com

Now this is a lens: Zeiss Apo Sonnar T* 1700 mm F4
http://www.dpreview.com/news/0610/06100101zeiss1700f4.asp

I wonder what the owner of this lens is using it for?
You'd have to be a long way from the wildlife.

Daniel

On some of the images you'll see the writing on the right side of the lens is in Arabic...
If you were a rich sheik with a camera fetish who wanted to photograph desert animals, this would be an interesting beast. But I'm sure there could be lots of other uses also.

You'd have to be a long way from the wildlife.

A common fallacy when considering long lenses. The more air between your lens and your subject, and the greater the magnification, the lower the resulting image quality (especially in hot desert air: shooting at dawn would be best).
A long lens simply lets you look at smaller subjects, but there's no substitute for getting reasonably close if you can!

Of course, it could be owned by the sheik who is starting the A1 series in Dubai - he seems to own everything special

long distance wildlife photography

yeah, stay in your lounge room but geez, 256kg!!

Also note that this lens is designed for a medium-format camera with a 6x6 cm negative. Thus the diagonal field of view of this 1700mm lens is equivalent to an 867mm lens on a 35mm full-frame camera.
This is a slightly wider view than you get with a 400mm lens + 1.4x TC on an EOS 30D!

Getting f/4 and with (hopefully) decent quality across a 6x6 cm frame is what's impressive.

As DaveB points out, unless the air is perfectly calm and clear, really long focal lengths are not ideal, much better to get close in with less fl. Having taken plenty of photos over the years through telescopes of varying focal lengths with effective focal lengths of several metres this has become obvious to me! I did however get some ok images of Greater Gliders one night with a telescope, after carrying it several km on my back, and upwards ~400 vertical metres! Lighting was provided by my Metz CT45 using a PVC tube and magnifying glass lens to give me a very narrow angle flash. On a later date I did get some much better images of Greater Gliders at a friends place who was a WIRES carer, with a standard lens
Given the weight of that beast, a telescope would be a better option, much less weight, and even with a fancy optical design, probably a lot less $$!

Gordon