DOF

[xfloggingkylex]

Yeah....thats what I meant. I cannot see the blades, but I can see the image getting darker.

Can this also be used to select the correct aperture (in Av) for the image?

I only use DOF preview if I am trying to get a certain amount of the image in focus, no more or less. I just hit the preview button and manually focus so what I want is focused clearly.

 

[Digital Matt]

Distance of focus is not a term I would use because it could be misleading. I could have a depth of field of 15 feet, like 3 feet in front of my subject to 12 feet behind them is in focus. This is not the same as saying that I was focused at 5 feet. Let's just call it what it is. Depth of field, or sometimes referred to as depth of "focus". (rarely)

 

[EOS_JD]

Never heard distance of focus..... Heard of Hyperfocal distance which is an area in front of the camera that you focus on and everything beyod will be in focus to infinity.

 

[EOS_JD]

Can this also be used to select the correct aperture (in Av) for the image?

Absolutely yes. This is why it's there. It allows you to see what is in focus.

 

[Flash Harry]

Never heard distance of focus..... Heard of Hyperfocal distance which is an area in front of the camera that you focus on and everything beyod will be in focus to infinity.

depends on what aperture you have set and your distance to subject still. H

 

[EOS_JD]

depends on what aperture you have set and your distance to subject still. H

..... and focal length.....

Yes i should have stated the a depth of field calculator will give information relating to your settings - you plug in the distance to subject, focal length and aperture and the DOF calculator will provide the near and far distances of acceptable focus.

For many wide angle settings focus to infinity is pretty easy to achieve.