[davidmanze]

Of the DSLR camera manufacturers, only Pentax offers a telescope lens, a 560mm f5.6. It does AF, is expensive, and not the greatest performing lens one can imagine. And pretty expensive.

The lens was only tested by PentaxForums in their early days, surprisingly user results are filtering through showing in fact that it "is" a very sharp lens indeed, some bemoaning it's unfortunate review, even it's price is now down to a reasonable level sometimes at  $4,000, not out of the way considering.

   It's ludicrously unwieldy size unfortunately, remains unchanged!