A-Dep setting on Canon DSLR

swag72

swag72

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Reading my Understanding Exposure book, landscapes are talked about along with a small section on the automatic depth of view setting that is on the Canon DSLR's.

What I am unclear on is where I focus on a picture with this setting? I understand that it is most useful for the landscape shot? So once I put it on this setting, is there anything I need to do? Do I focus differently using A-Dep than say a manual setting?

Does anyone use this setting?

Look forward to learning something new:thumbs:
 
IIRC you focus on the furthest point you want in focus and then the nearest and the camera shouldwork out the settings needed to keep the area in focus. Take the shot. :)
 
Not tried it myself for landscape but when your out next try it with it on and then take one yourself and see what they both look like when you are back.
 
had it on my old Canon fil SLR - never found much use for it then either.
 
The book says all the areas covered by the red focusing points should be in focus, the camera selects all the focus points and works out the depth of field. That said I have never got it to give me the same exposure twice, even on a tripod! Wayne
 
A-DEP doesn't work like that at all :lol: Have a look at page 99 of the manual for an example of its use. What actually happens is all the focus points are enabled and the camera tries to work out what f stop will be required so as the DoF will be large enough to get whatever is under each focus point in focus. Sometimes it works (fairly well) and sometimes it doesn't - more often it doesn't is my experience.
 
Prob best off using manual or Av mode instead and using the DoF preview button to give you an idea of how the exposure will turn out.
 
Gofer said:
A-DEP doesn't work like that at all :lol: Have a look at page 99 of the manual for an example of its use. What actually happens is all the focus points are enabled and the camera tries to work out what f stop will be required so as the DoF will be large enough to get whatever is under each focus point in focus. Sometimes it works (fairly well) and sometimes it doesn't - more often it doesn't is my experience.
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Ooops!! Not used it on mine just going by how it worked on my old EOS 5.:bonk:
 
Peter Loew said:
Prob best off using manual or Av mode instead and using the DoF preview button to give you an idea of how the exposure will turn out.
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I have to agree it's a better solution to A-DEP, but the trouble with using the DoF button is that the screen gets so dark at the smaller apertures it's practically impossible to see anything at all let alone what's in focus and what's not. This seems to be especially true on crop cameras and cameras having pentamirrors rather than pentaprisms. I find a DoF calculator is a good a tool as anything : http://www.dofmaster.com/dofjs.html
 
I think the way A-Dep works differs slightly between older and new cameras?

But I don't really trust it. And I certainly don't trust the lens stop-down botton, which is hopeless in practise.

So when in doubt, I use one of these - a handy depth of field calculator called ExpoAperture2, here:

http://www.bristolcameras.co.uk/p-expoaperture2-depth-of-field-guide.htm

It's good for sure, but I also check the image by zooming in on the camera's LCD. I find the screen on my 40D is just about good enough for that.

Richard.
 
chilliz said:
Ooops!! Not used it on mine just going by how it worked on my old EOS 5.:bonk:
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That's just how it works on my EOS3. Focus on the near part of the scene and you get 'DEP1' in the viewfinder. Focus on the far part of the scene and you get 'DEP2' in the viewfinder. The third half press of the shutter button selects the required aperture to bring those two points into focus. I haven't used it but it seems a far more useful implementation of the idea.
 
So, for best pic I need all the focus points on - AND ........... Where do I have the middle focus point? Foreground, roughly middle of the pic (where they may be no specific interest) or backgound?:thinking::thinking:

Sorry guys - I am sure these are really dumb questions.
 
CT said:
That's just how it works on my EOS3. Focus on the near part of the scene and you get 'DEP1' in the viewfinder. Focus on the far part of the scene and you get 'DEP2' in the viewfinder. The third half press of the shutter button selects the required aperture to bring those two points into focus. I haven't used it but it seems a far more useful implementation of the idea.
Click to expand...

so you do focus twice then???/ just as i thought i was getting the hang of the setting lol
 
shaun32 said:
so you do focus twice then???/ just as i thought i was getting the hang of the setting lol
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Well that's how it works on the EOS 3 and some other older EOS film cameras, but with EOS DSLRs, it's now just as others have said - enable all AF points, and the near and far points in your image have to be within that cluster of AF points.
 
swag72 said:
So, for best pic I need all the focus points on - AND ........... Where do I have the middle focus point? Foreground, roughly middle of the pic (where they may be no specific interest) or backgound?:thinking::thinking:

Sorry guys - I am sure these are really dumb questions.
Click to expand...

They're not dumb questions Sara - far from it, in fact I think you can see the problems with this crappy system - hence the questions.

You need to enable all AF points and then get the near and far parts of the scene you want in focus over AF points in the cluster - it doesn't actually matter which ones. The camera then calculates the aperture to bring both those points into focus.

If you wanted say a clump of grass in the near foreground in focus as well as everything else to infinity, I don't think the area covered by the AF cluster is big enough, so it's pretty limited IMHO.

You'd probably be better off using a DOF chart, or having a guess at the hyperfocal distance and stopping down to f8 or f11.
 
Gofer said:
A-DEP doesn't work like that at all :lol: Have a look at page 99 of the manual for an example of its use. What actually happens is all the focus points are enabled and the camera tries to work out what f stop will be required so as the DoF will be large enough to get whatever is under each focus point in focus. Sometimes it works (fairly well) and sometimes it doesn't - more often it doesn't is my experience.
Click to expand...

Yep! Wayne :'(
 
You don't say which model camera you have but in the later models you DON'T focus twice, and you don't have to turn on all the focus points, the camera does that for you in ADEP mode.
A better bet is a tripod, AV mode set the camera to F16 (or there abouts depending on subject) and use one focus point to focus about a third of the way into the picture. Wayne
 
CT said:
That's just how it works on my EOS3. Focus on the near part of the scene and you get 'DEP1' in the viewfinder. Focus on the far part of the scene and you get 'DEP2' in the viewfinder. The third half press of the shutter button selects the required aperture to bring those two points into focus. I haven't used it but it seems a far more useful implementation of the idea.
Click to expand...

Agreed, I can`t see the point in the latest idea at all, as has already been suggested, using the hyperfocal distance method of focusing may be of much more use.
 
Gofer said:
I have to agree it's a better solution to A-DEP, but the trouble with using the DoF button is that the screen gets so dark at the smaller apertures it's practically impossible to see anything at all let alone what's in focus and what's not. This seems to be especially true on crop cameras and cameras having pentamirrors rather than pentaprisms. I find a DoF calculator is a good a tool as anything : http://www.dofmaster.com/dofjs.html
Click to expand...

just a thought, with digital just take the shot then check it on the lcd, that way it will be properly exposed when you look at it
 
chilliz said:
Agreed, I can`t see the point in the latest idea at all, as has already been suggested, using the hyperfocal distance method of focusing may be of much more use.
Click to expand...

Well, I'm sure Canon know their market, and the truth is DSLRs are now attracting huge numbers of new users who want the quality images which a DSLR can give them, but really don't want to get any more involved in the technical side than they have to - hence all those (to most of us) daft settings on the mode dial. As long as modes like this produce the results for them sometimes I suppose they'll be content, and it's no detriment to them. :shrug:
 
Just had a thought, with CS4 theres a stacking system for focusing, you shoot refocusing at different points in the image, PS then stacks them to get it all in focus (at least thats the idea) haven't actually tried it though. Wayne
 
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