Depth of Field question

[Karlos]

Just a quick one, if the subject you are shooting is far away, would you get an apparent greater DOF for a given aperture than if the subject was much closer?

[Karlos]

http://www.dofmaster.com/dofjs.html

Just answered my own question. :cool:

[John_B]

Karlos,
Yes :)
Here is a site that will give the the exacts
Online Depth of Field Calculator (http://www.dofmaster.com/dofjs.html)

[cecilc]

Ahhhh ...... Karlos ....

Another fan of Aphex Twin, I see .....
Nice avatar .....

[DrPablo]

As you'll see if you look at the equations in the DOF calculator, aperture is the least important variable as compared with distance to subject and lens focal length.

So you don't need to have an f/1.2 lens to get a shallow DOF. Just pick a close subject with a background that's far away. I can show you my own examples of photos taken at f/7.1 with that 'dreamy' background blur, simply because I used long focal length glass, a close subject, and a distant background -- and with the narrow aperture I was able to get my subject 100% sharp.

The thing with aperture, though, is it's the only DOF parameter that doesn't change your composition. So it's still important. It's also important to think about lens aberrations when wide open and lens diffraction when the aperture is narrow. But it's very helpful to think about the other DOF variables if selective focus is important to your shot.