Post by USM on Nov 23, 2006 17:12:25 GMT 8
P, Av, Tv and M modes all meter for flash in different ways. Bear in mind that the camera meters for ambient (existing) light conditions and flash illumination independently.
P (program) mode keeps the shutter speed between 1/60 sec and the maximum x-sync speed of your camera. In P mode, the camera uses the flash as the primary light source for the foreground subject. If the ambient light levels are low, the background will turn out very dark. This is because the flash is not illuminating the background and the shutter speed is too short to expose adequately for background areas.
It does this so that you shouldn’t need a tripod, even if light levels are low. It then tries to illuminate the foreground using flash.
Av (aperture priority) and Tv (shutter speed priority) modes set the shutter speed or aperture to expose for the existing light conditions correctly. They will then fill in the foreground using flash. If light levels are low you will need a tripod to avoid blur. In such instance, slow shutter photography is occurred. In Av and Tv modes, the camera meters for ambient (existing) light and fills in the foreground subject using the flash. It does not assume that the primary light source is the flash, and therefore the shutter speed it sets is the same as it would set if you weren’t using flash at all.
M (manual exposure) mode lets you set both aperture and shutter speed. The camera then automatically controls the illumination of the foreground subject using flash.
If the lighting is poor when using Av, Tv and M modes, trying using higher ISO and larger aperture will help bring up the background.
P (program) mode keeps the shutter speed between 1/60 sec and the maximum x-sync speed of your camera. In P mode, the camera uses the flash as the primary light source for the foreground subject. If the ambient light levels are low, the background will turn out very dark. This is because the flash is not illuminating the background and the shutter speed is too short to expose adequately for background areas.
It does this so that you shouldn’t need a tripod, even if light levels are low. It then tries to illuminate the foreground using flash.
Av (aperture priority) and Tv (shutter speed priority) modes set the shutter speed or aperture to expose for the existing light conditions correctly. They will then fill in the foreground using flash. If light levels are low you will need a tripod to avoid blur. In such instance, slow shutter photography is occurred. In Av and Tv modes, the camera meters for ambient (existing) light and fills in the foreground subject using the flash. It does not assume that the primary light source is the flash, and therefore the shutter speed it sets is the same as it would set if you weren’t using flash at all.
M (manual exposure) mode lets you set both aperture and shutter speed. The camera then automatically controls the illumination of the foreground subject using flash.
If the lighting is poor when using Av, Tv and M modes, trying using higher ISO and larger aperture will help bring up the background.