Range of Canon 550 EX vs. Sigma 500 Super DG

I'm adding a second external flash (have a 420 EX) for my D30. Budget favors the Sigma 500 Super DG, which I've read functions well with the D30 as master (PLEASE let me know if you think otherwise). The one difference with the Canon 550 EX that matters to me is the range of the 500 -- which begins at 28 mm, vs. the 550, which begins at 24 mm, since my favorite lens is the Canon 24mm 2.8 (GREAT lens). So question -- does the difference matter in the digital world where the 24 mm lens is more like 36 mm? Does the flash have a similar multiplier, or will my shots with the Canon 24 mm lens be fine with a Sigma 500 because the flash range of 28mm is broad enough for the effective range of the lens in the digital world of the D30?

You want to figure in the multiplier factor when using a D30, or any other similar digital camera, since the image that you are trying to capture is based on the multiplier and the focal length.

You seldom talk about the range of a flash unit. It is best to talk in terms of the guide number, and you must use the same kind of guide number, like in meters or in feet, and with the same ISO. Otherwise, you are trying to compare apples and oranges.

There are some other factors in selecting one flash unit versus another, like recycle time. I was shooting a group the other day, and the central subject kept saying "Hurry up. We have to finish now." Waiting on the flash to recycle can be frustrating.

Personally, I like a flash unit that will sunburn their foreheads.

---Bob Gross---