One of the most common confusion which occurs with the Canon EOS flash photography is the fact that the Canon EOS modes like the Program (P ), Shutter Priority (TV) , Aperture Priority (AV) and Manual (M) modes handle flash illumination is different ways. This is especially so when the ambient light is not strong. This guide will give a brief run down of how the various modes work when the flash is activated. This guide also assumes that the FP mode is not turned on.
The P (Program) Mode
Under the P mode, when the ambient light is low, the camera will be set to a high shutter speed to enable you to use the camera without a tripod stand. This is to enable you to avoid "motion blur" even though you are holding the camera with your hand. The P mode will work when the ambient light is low or high. When the ambient light is high, the camera makes the assumption that you will flash fill the foreground. Thus the flash will be low powered. If the ambient light is low, the camera will under the P mode will set the flash and the shutter speed appropriately to give the best possible result. Having said so, pictures taken under this condition will normally have a dark background.
The TV (Shutter Priority) Mode
Under this mode the camera will let you decide the shutter speed. It will instead choose an aperture priority to suit the shutter speed to ensure that the exposure level for the background is correct. The duration of the flash pulse will be determined by flash metering. In short, the camera always operates in fill flash mode under the TV mode as opposed to P mode. The Canon EOS system will also warn you if the background is too dim. This will be shown when the maximum aperture value of the camera lens starts to flash in the viewfinder. When this occurs, you should slow down the shutter speed. You will also require a tripod if you wish to avoid motion blur.
AV (Aperture Priority) Mode
With this mode, you can fix the depth of field (DOF) by adjusting the lens aperture. The camera will determine the correct shutter speed for exposing the background to the correct level. The metering system will decide also how long the flash pulse should be. You have to note that if the shutter speed is low, you will need a tripod stand to prop up the camera instead of using your hands to hold the camera. This is because at low shutter speed, your pictures will end up having motion blur. Just like the TV mode, the camera operates fill flash mode. There are several cameras which have the exception to this mode. The canon EOS10/10s and the Canon Elan II/ EOS 50 models has a unique function will lets you lock the X-Sync speed to the Shutter Speed.
Manual (M) Exposure Mode
Under this mode, you will specify both the shutter and aperture speed of the camera. You will also determine the exposure setting of the camera. The camera will, through the flash metering system, calculate the flash output to illuminate the fore-ground. - 16651
The P (Program) Mode
Under the P mode, when the ambient light is low, the camera will be set to a high shutter speed to enable you to use the camera without a tripod stand. This is to enable you to avoid "motion blur" even though you are holding the camera with your hand. The P mode will work when the ambient light is low or high. When the ambient light is high, the camera makes the assumption that you will flash fill the foreground. Thus the flash will be low powered. If the ambient light is low, the camera will under the P mode will set the flash and the shutter speed appropriately to give the best possible result. Having said so, pictures taken under this condition will normally have a dark background.
The TV (Shutter Priority) Mode
Under this mode the camera will let you decide the shutter speed. It will instead choose an aperture priority to suit the shutter speed to ensure that the exposure level for the background is correct. The duration of the flash pulse will be determined by flash metering. In short, the camera always operates in fill flash mode under the TV mode as opposed to P mode. The Canon EOS system will also warn you if the background is too dim. This will be shown when the maximum aperture value of the camera lens starts to flash in the viewfinder. When this occurs, you should slow down the shutter speed. You will also require a tripod if you wish to avoid motion blur.
AV (Aperture Priority) Mode
With this mode, you can fix the depth of field (DOF) by adjusting the lens aperture. The camera will determine the correct shutter speed for exposing the background to the correct level. The metering system will decide also how long the flash pulse should be. You have to note that if the shutter speed is low, you will need a tripod stand to prop up the camera instead of using your hands to hold the camera. This is because at low shutter speed, your pictures will end up having motion blur. Just like the TV mode, the camera operates fill flash mode. There are several cameras which have the exception to this mode. The canon EOS10/10s and the Canon Elan II/ EOS 50 models has a unique function will lets you lock the X-Sync speed to the Shutter Speed.
Manual (M) Exposure Mode
Under this mode, you will specify both the shutter and aperture speed of the camera. You will also determine the exposure setting of the camera. The camera will, through the flash metering system, calculate the flash output to illuminate the fore-ground. - 16651
About the Author:
Tim Harris is a canon camera enthusiast. For tips on choosing and buying cameras, do check out Canon OS Camera website. Camera 40D Digital Rebel XTI 3D Blog
