For that kind of money you can get a 3 chip camera for video. I can't see why you would want a camera that is mostly for stills if you are doing mostly video. Don't get me wrong, I have the 7D and the video is awesome but if you're not shooting a a lot of stills, you might be better off with a used Canon XL1 for which you can still add Canon EF lenses. Yes, it's not HD but I don't know what your budget is. Shooting video with the 7D isn't as easy as with a camera that is "Made for video". If I was you, I would find a place that has a demo of a 7D, bring a CF card and shoot a little video in the store and see how you like shooting with it. It's very different from shooting with a video camera. You can rig the video capable DSLR's to work more like a video camera but that equipment is also very expensive: upwards of $1500 for the rig or more. So, now were talking around $3100, not including expensive, large CF cards since the 7D shoots large files. You can get about 3 minutes per GB. Three 8GB cards will run you around $200. You have to get fast cards too not cheap ones. I recommend Sandisk Extreme III or better. (Not Ultra). So again, you might be better off spending that kind of money on a dedicated video cam. The quality of the 7D video is about the same as the XL1 in low light, there is some noise. The XL1 is the only 3 chip cam I can comment on since I used to own one but there may be others out there with HD capabilities now for less or about the same as you would spend on the 7D and a rig.
thank u robert! it was so detailed. I do stills too, just for the passion and do own a cannon 5d mk1 which unfortunately does not have video capability. But i do have the lenses. I am basically a film maker who has only shot on film thus far. Recently i produced an experimental film which was shot on Red. Quite liked the freedom digital technology provides. So was planning out another experimental film involving a lot of macro closes which i thought a 7D could achieve. Just experimental stuff ie about it. I do have an XL1 and a sony z2 too but wanted to see how different this would be. When u do have the time, please do check out my pics too. Would welcome ur comments and i shall keep u updated regarding my experiments! reg