Editing Canon dslr video

I have a Canon SX1 IS which shoots in full HD 1080p. The first thing I'd suggest is that you will need more RAM - 12 to 16 GB; also, I've not used FCP, but generally use FCE, iMovie, and iDVD and rendering takes a lot of processing power as well as RAM. Your profile does not specify which iMac you have; my i3 is considerably faster than my older 24", but it still takes time, especially if you will use 1080p footage. That will also result in unbelievably huge files (how much empty hard drive space do you have??). So, yes, you can do it, but it will still take time - if you want to have a more professional setup, then I'd suggest you invest in a Mac Pro.

And, you might want to consider using a high speed card reader for your SDHC cards (rather than attaching the camera) - it's less cumbersome and saves batteries.

Well, that person may be more knowledgeable - I'm not a pro, just a "regular" user who likes to make movies with special effects, etc. I did notice a major improvement in rendering and encoding times comparing my old 2.16 GHz / 3 GB RAM iMac to my new 3.2 GHz / 12 GB RAM iMac - not sure if it's just the processor and/or the increase in RAM (my gut feeling says it's probably a combination of both). The short sequences I edit in FCE (mostly use it for layering several videos) are all exported into iMovie to be finalized and put together there, so I use Quicktime settings (usually H.264 because that has given me the best quality results). Occasionally, I use MPEG Streamclip first to reduce the clips from 1080p to 720p because I've found that I can't see a difference on my particular HDTV and it makes working with the much smaller file size a lot faster. There again, I use H.264. I've never used pro-res - checked all the settings in FCE and could not find it (since that is the mini or "dummy" version of FCP, it may not be available?).