Think of a big lens. A big shiny lens. Then crank up the shine to eleven.
When you've got a lens like this you don't just give it a number, you call it the Powerpack. Does your camera pack this much power? The filter ring accepts regular (!) 111mm filters for your convenience.
The mount is old-school 6x6 Hasselblad folks, none of that wimpy 35mm stuff. It's that big.
I doubt I'll ever come across one of these. I stumbled on the documentation looking for evidence that Carl Zeiss might re-release a 4/300 lens design for ZF.
I did find a review of this monster on Shutterbug's website. Check it out, the writing is hilarious. Some note-worthy quotes:
“What the hell is that?” asked a local photojournalist. “Why, this is my Zeiss 300mm f/2.8 APO with 1.7x APO-Mutar extender on a 203FE body with PM 90 prism,” I casually remarked. Impressed, he shrugged and walked away. Needless to say, when I staked out a position the print journalists cleared a space for the guy with the prettiest lens. [Shutterbug]
At $21290 I'm going to have to pass on this one I'm afraid.
Now if Carl Zeiss were to launch that 4/300 T* I was looking for...