Question on shutter priority

[shufflemoomin]

If I'm shooting in shutter priority with a canon camera, how does the camera balance aperture and ISO? Will it lower the aperture as much as possible before it starts to raise the ISO or the opposite? i.e if I have a 2.8 lens, will it continue to lower the aperture to 2.8 and then start rising the ISO to compensate or will it automatically balance the two without either one taking priority?

 

[artyman]

It will lower the aperture as far as it can then underexpose, you would need to increase the ISO. Depending on your model you could select auto ISO and set both shutter and aperture to what you want with the camera altering the ISO to give what it perceives to be the correct exposure.

 

[arad85]

Lowest ISO available so increases aperture then raises ISO IIRC. Easy enough to try...

 

[shufflemoomin]

I did try, but it was adjusting both aperture and ISO, so I wasn't sure what methods the camera was using. Just to recap: It will leave ISO as-is, lower the aperture as low as it can and THEN it'll start to increase the ISO if needed?

 

[Roy C]

When shooting in Tv mode and auto ISO with the 7D the camera will return a wide open aperture (or maybe stopped down 1/3rd of a stop) from there it calculates exposure by changing the ISO. I use this method all the time with my non IS 400/5.6 which is tack sharp wide open.

 

[Willid1]

If I'm shooting in shutter priority with a canon camera, how does the camera balance aperture and ISO? Will it lower the aperture as much as possible before it starts to raise the ISO or the opposite? i.e if I have a 2.8 lens, will it continue to lower the aperture to 2.8 and then start rising the ISO to compensate or will it automatically balance the two without either one taking priority?

You don't say which camera you are using but make sure you don't have safety shift enabled as this will allow the camera to start dropping the shutter speed as the light reduces (assuming you have not already set auto ISO)

HTH

David