I've never been much of a gearhead but I've always wondered as to what a picture taken with this lens looked like and why anyone would want one. If you've also wondered the same, try here.

http://www.bhphotovideo.com/c/find/newsLet...ll-L-Lenses.jsp

I'd still like to see what National Geographic did with it though!

I've always thought of this lens as a bit of a joke; more of a wealthy photographer's showpiece/toy than a truly useful tool, but I guess it does have its niche. Since it starts at f/5.6, it has some advantages over the 600mm f/4 with a 2x TC. It is a 1/2 stop faster wide open, and TCs usually distort bokeh into ugliness, which is one reason why, even at the same f/stop, one might prefer the longer lens over the TC, even if the shorter lens with the TC is sharper in the plane of focus, which I believe is true in this case.

I wonder what it would go for on eBay? Right now someone is trying to sell a Sigma 300-800 for Canon and has listed it a couple of times.

Myself, I find that a 30D or 40D, 1.6x factor, with a Sigma 120-300 f2.8 or Canon 100-400 f5.6 IS, and 2x get me enough reach and I can actually hand hold them. Although a BushHawk shoulder stock makes holding them nicer.

The Sigma with a Sigma 2x TC gets me 960mm effective at f5.6. Don't think about trying any other 2x TC, it is too soft.

The Canon with a Canon 2x TC gets me 1280mm effective at f11. I have taped the contacts on the Canon 2x TC so the camera still attempts to auto focus. (www.allensphotoblog.com/blog1/2006/12/the_old_tape_trick.html)

Here in the sunny Finger Lakes of New York state, f5.6 is usable, f11 really isn't.

And Sigma now has the 200-500 f2.8 zoom listed on their web site.

I hope B&H took this on consignment, rather than buying it outright. They could have it in their inventory for a long time.

Just for silliness' sake http://www.canonfd.com/mirrorlenses/pages/page10.html