I'm interested to know what equipment you all use for wildlife photography and what you think of it. I've been contemplating getting a 500mm f4 lens and a new 1d Mk3 to go with it. The main thing that is worrying me about this lens is the portability issue. I currently use a bigma on a 30D, mounted on a monopod. I don't really want to get rid of this lens, so bearing this in mind do you recommend any other lens I should get?
Any advice would be appreciated, Cheers, Mark.
P.S Ive got a budget of around £7500 (for camera, lens and tripod+head)
LOL - I can only dream of a budget like that 
All I can afford is a box Brownie and a box of Swan Vesta ![]()
Sound like your used to lugging some weight so a few more trips to the Gym should get you fighting fit. I suppose a lot depends on you style of shooting birds. On the hoof or sit in a hind.
I got a 500 f4 IS last year and love it, I honestly thing it's the best birding lens around, OK it's not got quite as much reach as the 600 f4 but it is much smaller and lighter. I use mine with a 40D and am very happy with the performance.
If you are buying a 500 f4 (~£4000) you also want a 1.4x tc (£200), good tripod and head (~£1000 for a Gitzo and Wimberley) and a bag to lug it around in (I use a Tamrac at ~£100). So that lot would account for ~£5300 of your budget, so you could either stretch your budget to the limit and buy a mk III with it's amazing high ISO performance... or you could compromise a bit and go for a 40D (£700) not quite as good in poor light but still a great camera. Best bet would be to go to a shop and try the cameras, see if you feel the mk III is worth the extra.