5d vs 5d Mark II (vs 1ds Mark II)

I am a Fuji/Nikon DSLR shooter and thinking of trying Canon. Fuji DSLRs are seemingly at end of line (though I still love my S5 and S2) and I find the default Nikon color pallet doesn't quite do it for me lately (not saying it's bad, but just like Fuji vs. Kodak in the film days, each catered to a slightly different visual "taste").

Anyway, I'm considering buying a used Canon and the full-frame 5d (Mark I) is remarkably affordable. The 1ds Mark II is pushing my budget and the 5d Mark II is probably out of my budget unless I'm really desperate (and also potentially willing to face the ire of my spouse).

Before going on let me clarify a few things:

• I don't care about bells and whistles like frame rate, video, and say cool in body JPEG processing (I shoot RAW).

• ISO is nice but also not required.

• Megapixels are nice, but 12 mp is more than sufficient.

In the end, IQ is mostly what I care about - the camera can be relatively klunky (I did say I love my S2 still) as long as the color and sharpness are good. Coming from an S5, DR would be nice too, but I'm willing to compromise.

So, if you're willing, does the 5d IQ compare well to the 5d Mark II or is the 5d Mark II really definitively better IQ-wise and you wouldn't go that route?

Assuming they are comparable (which I admit is a big assumption), is it worth the extra $$$ for the 1ds Mark II? Is it "comparable"?

Any advice here would be appreciated (BTW - I know this has probably been discussed to death at one point, but because the 5d and 5d II are essentially named the same, it's hard to come up with a search that yields what I'm after)(and, yes, I'm lazy - sorry).

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Matt Fahrner
http://boinkphoto.com