I'm relatively new to DSLR shooting, but I have a new baby and am taking a lot of indoor photos on a T2i. Any recommendation on the minimum size flash I can live with? I'm considering either the 270EX or 430EX, but I wonder if anyone knows whether the 270EX is tall enough to light the frame if I use my sigma 10-20 lens. Not a pro, so looking to spend less if possible.
Spend $21 and get the Gary Fong Puffer for your pop-up flash. Learn flash exposure compensation...then go for the speedlight. Meanwhile you will get some decent kid shots and not blind your baby. Even cehaper imitations on ebay. You will want the dedicated flash of course. Get a cable and be able to hold and direct it off the hot shoe...another $12 on ebay.
Flash from near the lens, whether it comes from the built-in flash or a speedlight in the hotshoe, isn't very natural looking because natural light comes from overhead hitting and modeling shape from a downward angle. So moving from built-in, to 270ex, 430ex or even a 580ex will produce progressively more light, but not improve the lighting much.
Bouncing light off the celing is a way to change it's direction. Adding a diffuser will split the light bouncing some up then down off the ceiling and some forward, creating a downward "key" modeling vector and a forward "fill" vector similar a dual flash configuration. But the caveat is bouncing is inefficient so you'd want the most powerful flash you can afford, or justify lugging around. So with that in mind if the 430exII fits your budget it will give you more power and thus more bounce, diffuser and range and thus more lighting options than the 270ex.
I have some tutorials you may find helpful at http://photo.nova.org. I use a pair of 580ex flashes for location shooting, raising one off camera on a bracket and using a bounce-forward diffuser for single flash shooting, and it my becomes my fill source and Master controller when using a second flash off camera. If you start with a 430ex and then later decide to expand your lighting options by getting a second flash that logistically simple set-up may work for you for chasing the rug rat around the house and yard. When shooting things like a kid's birthday party I just park the off camera light on stand in the corner out of the way of little feet as "rim" light, known the flash over the camera on the bracket will provide flattering, natural downward modeling on the faces.
Thanks to all of you for your advice - I really appreciate it. I decided to take the plunge and go with a 430EX, and fortunately had no trouble finding a used one on the FM forum.
