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But, there is one *very important* difference between how exposure modes on Canon & Nikon work, that McNally doesn't mention. On p. 12, he write "The camera EV is an exposure-wide adjustment. If you program underexposure into the scene, then you're programming underexposure into the flash as well." This is *not* the case on Canon.

On Nikon: the camera EV and flash EV are indeed linked: lowering the camera EV lowers the flash output. So, to highlight the foreground, you go -2 EV on the camera, +2 EV on the flash (e.g., p. 34, p. 61, and many many photos in the book).

But on Canon, this is *not true*: the camera EV and flash EV are independent. Dropping the camera EV drops the ambient exposure, but keeps the flash output the same! So to do the same as above on Canon, you want to do -2 EV on the camera, and leave the flash at 0 EV. If you do what McNally says, you'll end up over-flashing your subject on Canon.

This difference is *not* well documented, but you can find some more info on it at Canon's web page -- Google for "Canon EOS speedlite system tips" and click on the tips by photographer Stephen Wilkes, and there are a lot of sample photos for how this works. Neither system is better or worse -- but you do need to be aware of the differences!Get more detail about The Hot Shoe Diaries: Big Light from Small Flashes.