EOS 300D Shutter Speed Restricition.

You may be confused, or you may be able to understand all this.

Regardless, lets review the basics of flash.

1/ Sometimes the purpose of the flash is to be the main light for your photo, and sometimes the flash is intended to fill in shadows or add a little sparkle, especially to eyes (they care called catchlights.)

2/ As you change the mode dial (ASPM or some similar sequence) you also change the purpose of the flash.

3/ Your camera has what's called a focal plane shutter, and that is the two-curtain type that's been explained earlier.As long as one curtain is open and the other curtain has not started to close, the entire sensor is visible to the subject at the split second the flash goes off and illuminates the subject.

4/ The fastest shutter speed that allows the shutter to be completely open is 1/200.

(If you try to take a flash photo at 1/400 by setting the camera to manual, you'll see part of the subject is dark - that's the part covered by the second curtain.)

There's lots more to learn, but let's jump to the splash shot.

5/ MORE THEORY

When you use flash, you are actually taking two pictures at the same time.

Picture one is taken with the light that comes into the camera through the lens' aperture (f4, f5.6, whatever) for however long the shutter is open (1/60, 1/200, etc.)

Picture two is taken when the shutter is open, exposed by the very short split second time the flash goes off, at the same aperture.

So you could have a ball rolling across the frame, illuminated by the light in the room, blurred because the shutter speed is slow, and then the same ball is very sharp, "frozen" by the split second the flash went off.

If you were working with a splash, having dim room lights means that the drop and the water is not exposed enough to see (depending on the shutter speed and aperture and ISO) but it will be properly exposed by the very brief burst of flash.

Hope this helps.

BAK