wrote:
I have a question for those of you that are very serious about
wildlife photography.

I currently own all Canon equipment and have recently started making
the move toward digital. My longest lens is the Canon 100-400 IS USM.
I am looking at purchasing a longer lens and am torn between the Canon
500mm f/4.0L IS USM and the Canon 600mm f/4,0L IS USM lenses. The cost
difference between the lenses on B&H's website is about $1,700.00.

I enjoy shooting wildlife photographs of small and large mammals as
well as birds. Can someone please make a recommendation on which lens
would be better for the type of photographs I would like to take?

The weight of the lens is not an issue for me as I rarely hike or
backpack to remote locations when photographing wildlife. I'm just not
sure which lens would be the best choice for wildlife photography and
would like some recommendations before spending such a large sum of
money on a lens.

I made this choice a couple of years ago. I wanted the 600 for
astrophotography, and my main goal was astro; only occasional wildlife.
I mainly did large format landscape work before. Then after
looking at the portability, especially on airplanes, I decided on
the 500. I am glad I did. As Bill points out, the 500 can go
into a lowepro photo trekker AW backpack with bodies, lenses and
accessories and be carry on legal. It is so much fun carrying this
outfit around, I've now done more wildlife photography than
astro since I got it. I have also heard of others downsizing
to the 500 because the 600 is so big and heavy. But then I've also
talked to others who have upgraded from a 500 to the 600!

The other thing to consider, is you really need a good carbon fiber
tripod (e.g. gitzo 1328, 1325 minimum) and wimberly head. That
eats up most of your $1,700 price difference. With the 600 you need
an even bigger carbon fiber, like the gitzo 1348 (minimum).
Then add flash bracket and flash extender...the money keeps flying out!

Both lenses are great.

Some 500mm images:
Birds: http://www.clarkvision.com/galleries/gallery.bird

Foxes: http://www.clarkvision.com/galleries/gallery.foxes

Astro: http://www.clarkvision.com/galleries...y.astrophoto-1

Roger Clark