The 1Ds has: - slightly more dynamic range - slightly more resolution - slightly different color rendering - extensive weather sealing - several more custom functions and features that only 1-series bodies have, e.g. AF point spot-metering - more focus screens - built-in grip - longer-lasting battery - larger buffer - more frames per second - dual card slots - larger viewfinder - 45-pt AF system (26 assist, 19 selectable) - can AF with f/8 lenses - silent shooting mode what it lacks compared to the 5DII is native ISO 3200 and 6400, video, a high-res LCD, and it's more than double the cost. Click to expand.It's no worry, and really it's none of my business, (thanks for not taking my comment out of context BTW). Just quickly, have you studied up enough to know what the reasons for shooting FF are, or are you buying this camera because you've heard it's great and you've got the money. I only ask because the 5D mkII is a very specialized body that's well suited to some applications, and less well suited to others. Perhaps we can help you save some cash while getting the right body for you! Click to expand.Thing is: how many get even close to that?

Especially if you're not a pro * In any case, I think the OP should reconsider buying such expensive cameras if he doesn't have the experience to use such professional tools. Professional cameras and lenses are also heavy and you may actually take worse pictures -- or none at all, because you don't want to lug around all the equipment. Image quality doesn't matter if you don't take the photo @OP What experience do you have? Have you used (d)slrs already?

Download drivers, software, firmware and manuals for your Canon product and get access to online technical support resources and troubleshooting. EOS 5D Mark III - Support - Download drivers, software and manuals - Canon Europe.

What's your current equipment? What do you typically shoot? Click to expand.+1 the 1D series will totally kill the 5D in focus, especially in low light. Mac os java 8. That's the biggest difference IMO (along with weather sealing - shooting outside in the rain gets people's attention).

But really, if you don't know the differences, you really have no business trying to use a 1dS. There are a lot of options and a lot less handholding in a pro body. From a pure quality of picture image perspective, I doubt you'll see much difference. More money buys better performance in other ways, including durability.

The 1 series feels like a tank, the 5D feels like any other cheap dSLR body. I believe the OP is in the same position as me in that when I looked for a first time dSLR having no prior experience I looked at both the 5D and 1D Mark IIn (opted for the 1D finally) when they were JUST coming out on the market (the 1D being ~6 months old the 5D brand spankin' new). The reasoning behind why I went with the 1D for a first time dSLR was for the simple fact that I figured if I learned a pro body, pro controls etc not only would I have a camera that'd last (and believe me the 1D series last) a LONG time but I'd 'grow' into how it operates, the kind of IQ and features that maybe I don't need at the time but kind of nice to have down the road.

OP: It depends on your usage and what you'd like to do with the body since the 1Ds is designed for a level of performance that'd allow you to capture a lot of what you see around you quite easily due to its AF performance, battery life, ruggedness. It IS however heavy if you got a 580EXII and a 70-200 2.8 on it then it can weigh upwards of 9LB so think about where you'd want to take the camera and how long/much you're willing to lug around the body and lenses when going places. If you plan on shooting scene's with a lot of fast action, ski/sports/events, or you want the best performing camera AND are willing to learn/use/refine yourself then the 1D feels right at home. If all you care about is resolution, you don't mind if the body isn't weather sealed, (and lighter) focus more on portraits and don't mind having a video mode the can record in HD then the 5D Mark II fits the bill. +1 the 1D series will totally kill the 5D in focus, especially in low light.