for your SLR?
I debate this for myself based on my usage:
- XT Rebel
- Most shots candid indoors
- However I have to deal with high celings and also certain times when the "no flash" rule.
If I did, what should I buy?
Do I buy some sort of diffuser also?
Any other flash type accessories?
As soon as possible. Fill flash for *outdoor* shots is way more important than most people think (and why nature photographers tend to put fresnel lenses on their flashes.) Also, many newer cameras will use the flash for infra-red assistance for autofocus.
The best way to diffuse the light is with some sort of reflective material- index cards rubber-banded to the head and the head pointed straight up is an old-fashioned trick. There are some good instructions floating around on DP Review on building a bouncer out of the craft foam stuff you get at Wal-Mart. You have the advantage of being able to shape the stuff so you can produce a rounder shape to capture and reflect more light. Also, if you do it right, you can adjust the amount of "cup" for each shot. Otherwise, one of the standard "stick it on the front" diffusers will help. The larger the bounce or diffuser area, the softer the light, making for softened shadow/light transition areas.
It also depends on if you mean "candid" as in unposed or "candid" as in "They don't know I'm taking pictures." The first shot can be either one, but after that some portion of the targets will (if they're camera shy) avoid you like the plague if you use flash.
Get the flash off the lens axis with some sort of arm (which will also necessitate a cable) so you don't get red-eye and the catchlights are off center and up like light from the sun would be.
If you drag the shutter and you diffuse the flash's light though, you'll improve the quality of your shots significantly.
Control the light, control the outcome.
