A-DEP is more useful than I thought...

I was playing around with A-DEP mode on my 10D and discovered that if you just refocus

(with CF-4 anyway) the camera will come up with different combinations of shutter speed

and aperture and light up different focusing points in the finder, even if the camera doesn't

move. So, I figured I could use this to compensate for the lack of a DOF scale on lenses. I

have primarily used it to learn what aperture to set.

 

Anyway, try it a few times. It isn't as useless as I thought. It will actually cycle through

several settings, so if A-DEP doesn't give you the settings you want the first time, just

refocus. I'm not sure this works with CF4-0 or if your camera lacks custom functions.

<P>The normal DEP mode is better because you choose the near and far points. ADEP

often misses. However, it's better than nothing if you lain't shooting with a prime fitted

with DOF scale. I find it's most useful feature is selectively focusing for max DOF

(hyperfocus) for near and far points. I then disable AF and switch to Av mode and dial in a

smaller aperture value.</P><P>Here's an image I took last week with my 10D, EF 24

-85 3.5-4.5 USM, ADEP/Av mode, Hoya polarizer and Gitzo G1028:</

P><P><B>Multnomah's Source: Columbia Gorge, OR</B></P>

<img src="http://emedia.leeward.hawaii.edu/frary/Northwest_Images/

multnomah_1414.jpg">

PF: I'm curious as to what shutter speed you used for that (very nice!) shot. Looks slow, but I'm curious as to how slow.

 

Thanks!

Thanks Eric. I used F11 @ 1.3 seconds (-1/3 stop EC). I tried a little slower and faster

shutter speeds and

liked this one because it shows motion but still maintains some texture. Longer speeds

looked like fog!

A question . . . When using A-DEP mode do you need to have the camera set to multiple AF points, or will it also work when set to centre point AF ?

ADEP can only work with all AF points active. Why? It identifies AF points on near and far

objects and selects a focal point and F-stop that renders these points reasonably sharp.

With DEP mode of the EOS Elan series and 5/A2 you choose the near and far points with

the center AF point (DEP 1, DEP 2, shoot).

Puppy Face, I am wondering whether the technique you just described can be used for infinite objects. Does the A-DEP mode automatically determine, for example mountain range, as far objects?

 

Thanks,

 

 

Avan

<i>ADEP can only work with all AF points active.</i>

 

<p>Which is why it resets the AF mode to "all points active" when you switch to A-DEP even if you've selected a specific point in another mode. I certainly agree that the original DEP mode, included in EOS cameras since the 650, is much better than A-DEP. What were Canon's engineers and/or marketeers thinking when they decided to replace the uniquely useful DEP with the dumbed-down, dodgy A-DEP?

 

<p><i> Does the A-DEP mode automatically determine, for example mountain range, as far objects?</i>

 

<p>Yes, assuming you manage to persuade the camera to "automatically" select the nearby foreground as well as the background at infinity. I find that it helps to rotate the camera to position one or more focus points on the foreground and one or more focus points on the background. That often means putting the camera on a diagonal and rotating left or right, pressing the shutter release half way until you see all the appropriate focus points light up.

 

<p>Then consider using Puppy's technique of switching the lens to manual focus, going into Av mode, and selecting a smaller aperture. That gives you time to recompose the shot the way you want it, since A-DEP "times out" quickly unless you keep the shutter release pressed half way. A-DEP (or the older DEP) tends to choose a wide aperture, especially with wide-angle lenses. Stopping down gives more sharpness overall and makes it more likely that you'll get the depth of field you're looking for.