Stupid Question about flash on 30D

[Ursie]

I have always used ambient light for most of my portrait photography, but I really want to learn how to use the flash. I'm trying to figure out the basics of how the heck to make a flash work without completely blowing the highlights. I'm wondering if I must only shoot in full out manual to get the effect I'm looking for. I'd like to be able to use the flash as fill. Can anyone help me with the basic how to's of using flash. I know there is something straightforward that I am missing here. The thing I'm experiencing is that I always get really blown out highlights if I try to shoot in Aperture priority mode. A couple of things happen, when I set the aperature wide, the highlights are blown, if I set it smaller, the shutter speed wants to be way slow. Like 1/4 of a second. I've got a Sigma EF-500 DG ST EO-ETTL, but it doesn't seem to be communicating properly with the camera so that it offers too much light, even if I stop it down. Any suggestions would be appreciated.

[PacAce]

If you already know what shutter speed and aperture you want to use for your flash pictures, set the camera to Manual mode. If you're not sure what settings to use but still want to play around with the camera set to Manual mode, you can start by setting the shutter speed to 1/60 or 1/125 and aperture somewhere between f/4 and f/8. Take a couple of pictures and see what they look like. Try varying the shutter speed and aperture and see what works and what doesn't.

If you don't want to use Manual mode, the just set the camera to P mode and let the camera take care of itself.

In either case, make sure the flash is set to ETTL mode.

If you want to use the flash only for fill, then the assumption is that ambient lighting will be the main light source. In that case, you won't have any choice but to shoot in Av or Tv mode unless you want to shoot in Manual mode. And if the ambient lighting is bright, then you may even need to set the flash to high speed sync mode it the shutter speed set on the camera for the flash is causing your picture to get overexposed.

[Curtis N]

There are no stupid questions, and fill flash is anything but straightforward. Understanding of certain concepts is required. To begin with, you need to review your camera's instruction manual and make sure you know how to adjust exposure compensation (EC) and flash exposure compensation (FEC). Then you need to evaluate your images and determine if the blown highlights are from too much ambient light, or too much flash, then adjust accordingly.

If you have trouble figuring things out, post a sample image with complete EXIF info and we'll be much more able to help.

Have you read the Flash Photography 101 articles in the EOS Flash sticky thread?

[Ursie]

I'll go check out the articles you mentioned Curtis. I've been reading my manual, as well as my magic lantern guide, but somehow, I'm missing the connections with this in particular.

Also, can someone tell me how to save a photo at a reasonable size in CS2 with all the exif data intact?