Why No IV When There's Av And TV...?

68lbs

68lbs

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April 2008
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Is this a silly question...?

Why isn't there a mode where you could set your aperture and shutterspeed and the iso is calculated in-camera to give the 'correct' exposure? :shrug:

I can think of quite a few scenarios where I might shoot wide open, not want to drop below a certain shutterspeed, but don't have time to keep going and changing the iso.
 
There is. Usually called "Auto ISO" or "safety shift" which will up the ISO to give you the correct exposure if your aperture is already fully open and you still cant get the shutter speed you want.

On my 1DIII I can use Tv mode, set the shutter speed to 1/800th for example, and use the "set aperture value range" function to force the aperture to 2.8. I have ISO safety shift set to on when in Tv mode, so I nicely end up with the ability to shoot at my chosen aperture and shutter speed, and have the camera bounce the ISO up and down for me. Especially useful when shooting in a stadium where one side of the pitch is in shade and one side is in sunlight.
 
You would put your camera in M mode and set the ISO speed to auto. So yes, it's a silly question! ;)
 
68lbs said:
Is this a silly question...?

Why isn't there a mode where you could set your aperture and shutterspeed and the iso is calculated in-camera to give the 'correct' exposure? :shrug:

I can think of quite a few scenarios where I might shoot wide open, not want to drop below a certain shutterspeed, but don't have time to keep going and changing the iso.
Click to expand...


Not a silly question if your camera has no auto iso!

Unfortunately the 5D hasn't got Auto ISO like the new models, but it has got 'Safety Shift' under the custom functions, how this works for example is:

If you're shooting in AV mode ISO100, F2.8 and are using fill flash, the camera knows that it can only sync with the flash up to a certain speed. As you are in AV mode the camera will try to set the shutter speed but when it hits the limit of the sync speed it will adjust the aperture automatically to achieve the right settings for you, after the shot it will revert back to F2.8.

not quite what you are looking for but does help in certain circumstances (a lot)

ISO is manual on a 5D, upgrade to a mark II and you will be laughing :naughty:
 
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