I currently have a 5D but need to invest in a Canon backup body. I've been told that if I get the crop sensor as a backup I can then use the different focal lengths to my advantage. Now with 5D prices so low, its tempting me to get that instead of a 40D or even a 30D.

What do you guys suggest??

BTW - I have a D200 for sale in the used section.

Go with the 40D and marry that to the 70-200 IS.
Have your wides on the 5D and your tele on the 40D...

That's what I did when I shot my 5D/30D combo... all gone now, just switched back to Nikon.

Yeah, I was tempted to buy your 5D you had for sale.

Hope everything goes well on the switch back.

Hi Chet, I have a 5D and a 20D. I use the 20D to my advantage as a back-up AND for the extra reach with my 70-200 lens. I also like the fact that the 20D gives me 5 fps versus the 5D with 3fps, for those occasions when you need faster shooting.
I hope this helps a bit.

Is this going to be a second camera, or a backup? If it is a second camera and it is going to be used on a regular basis, get the 5D. If it is a backup, just buy a used 20D for around $500. Better yet, get another 5D and a used 20D, that way you will have a second body and a true backup for if something gets screwed up.
Cory

I'm kind of thinking opposite of Cory. If it is going to be used as a backup, then I would get another 5D. If it is a second camera, then I would possibly get a 30D/40D and use the crop factor to add variety when using my lenses. I just know that if I was shooting with my 5D and it suddenly failed I would want another full frame camera to continue shooting with.

I tried using a 30D as my second camera, thinking that I'd like the extra reach. But, the IQ was noticeably better on the 5D, and I really don't use the 70-200 that much anyway, much less enough to need a crop body for more reach.

I'm super happy dual-wielding my 5D's 24L/35L on one, 85L on the other.

I have been using two 5D's and I used to have the 20D's for my backup cameras. I recently sold my 20's and bought the 40D. I now wish that I had bough another 5D. I have the 70-200 on the 40D and the quality of the images is just not the same as the 5D.
I am probably going to sell the 40D's if they come out with a 5D replacement here in the next year. Borrow or rent a 5D...then you will see what I mean.

I have a 5d with a 20d backup. One time my 5d was acting a little funny so I had to use my 20d on an e-session. Man do I wish I had another 5d as backup. The 20 d just doesn't make as nice of files, and I don't need the extra reach. You can shoot on a 5d with the bigger files and crop and still have the same reach as a 20d with nicer files IMHO.

+1