SLRGear.com has a review of the gigantic Canon 800mm f/5.6L IS USM telephoto lens. Reviewer Andrew Alexander says this lens will test everything you know about photography: it demands the sturdiest of tripods, a strict shooting technique, and a camera that can benefit from its excellent optics.
â€œIt’s a sharp lens,â€ Andrew says of the mammoth lens, â€œbut not tack-sharp: approximately 2 blur units between Æ’/5.6 and Æ’/11, and between 2-3 blur units at Æ’/16 or Æ’/22. At Æ’/32 it becomes a bit soft and slightly uneven, at around 5 blur units.â€
The Canon 800mm f/5.6L IS USM lens sports a price tag of $12,000, definitely stratospheric, â€œbut for some shots, there is no other way to get this combination of focal length and aperture,â€ the review said. There is of course the cheaper Sigma 800mm Æ’/5.6 EX DG HSM APO at about $6,000.