A-DEP Critics, Represent!

Let's get one thing straight; I'm a complete idiot when it comes to much of this stuff - but I am trying to learn. My T2i has a mode dial setting, A-DEP, that I find useful but is criticized by many. Now that I have a 7D, I want to know how to get by without it.

A-DEP mode on the T2i finds the nearest and furthest focal points and automatically sets the depth of field to keep that range in focus with the best possible shutter speed, aperture, and ISO settings. Perfect for times when quickly taking a staggered group portrait in low light.

The 7D obviously doesn't have an A-DEP setting because no professional photographer needs it, right? Well, how do I handle the situation I described? I've done a bit of searching and have seen advice like, "Set your aperture to f/16 to make sure everything's in focus" or "A-DEP is for numbskulls who haven't learned how to use their camera." But, I haven't been able to find good advice on how to handle a staggered portrait in low light.

I realize that I could set my camera on a tripod, tape off the near and far points in the composition, and then consult a Depth of Field calculator to figure out the widest aperture that keeps everything in focus. That might work in a studio with stand-ins but is impractical for impromptu group shots. Posing the group on the focal plane, or setting the aperture to f/22 and letting the ISO run up to 3200 are workarounds, not solutions.

I read that some Canon cameras had a feature even better than A-DEP, called simply DEP, which allowed the photographer to designate the closest and furthest focal points by half-clicking on them.

So, with the 7D, am I back to the Stone Age, with a tape measure and depth of field chart? Or, is there a simple technique that accomplishes the same thing as the A-DEP function? Thanks for not filling this thread with comments about how stupid the A-DEP function is. What I really want to know is how you live without it.

simple solution from me, at least the way i do it.
set the aperture to best estimate value, then press depth of field preview button.
You can actually see which area is in focus.

However, this method is kind of difficult in low light, because the viewfinder is so dim, you cant really tell which area is in focus.

The best thing about DOF preview button, it is usable in any modes, so you dont have to change modes.

Try and error also may work.

I think reason DEP is better than A-DEP is because in the newer cameras at least, for A-DEP, you must have a focus point on both the nearest and furthest subject at the same time. DEP allowed you to put the focus point on the nearest/furthest subject, then recompose to cover the other subject, which gave you much more flexibility.

Thats about all I have to offer on this

to maximise depth of field I just use a small aperture (f8-16), and set my lens to focus a short distance in front of me then recompose, or just leave it as is, and take the shot.

The easiest way to see depth of field, prior to shooting, is to turn exposure simulation off, switch to live view and then press the DOF button from there. Since you turn of exposure simulation, the camera will keep the display brightness, if possible, across different apertures.

Apart from that I simply use experience. If you have you A-DEP equipped camera around, you can still use that to test out some setups, and then check which aperture the camera computes to use. Set that, and you'll achieve the same thing. Soon you'll know without thinking about it.

The DEP setting on my EOS 30 is even more convenient. Since AF on that camera is eye-controlled, you literally look at the closest part of the subject, half-press, then look at the farthest, half-press again and finally compose and take the picture. That they could have included on the 7D, even if there's no eye control.

See, no ranting about A-DEP being for idiots!

I wish they replaced the DOF Preview button with something useful like a Print button

A-DEP can be good tool for someone who has not learned the basics of exposure.

The bottom line is that, all other things being equal, depth of file is a function of aperture. Use P mode or Av mode and set the aperture to the largest number that gives you correct exposure. Bracket the shots a bit if you are unsure.

A-DEP can't perform magic. If it is too dark for the shot, it is too dark. Below are the limitations from the 40D manual on A-DEP.

You can use A-DEP and not understand all the limitations but when it is too dark or bright or you are too close you won't understand why A-DEP is not working. When you get to the point you understand all that you probably don't need A-DEP anymore.

Either take group shots in good light, set your camera to Av and take a couple of exposures at f8 and f16 OR get and study Understanding Exposure as a place to start.

With any luck, you will smile someday at the thought you started this thread.

This is where old MF lens have an advantage, they nearly all have a depth of field scale.I know that AF lenses usually have far less angular movement across the focussing range, to speed the AF response, which severely reduces the usefulness of the scale.

Alan

Thanks for the thoughtful replies. Using the DOF preview button seems to be the best available option, and is actually quite precise when used with Live View zoomed. Still a fairly cumbersome technique for snapping a quick group photo in low light.

The DEP feature (particularly the eye-controlled version) would have been a nice inclusion on the 7D, easier to use and more precise than A-DEP.

Not being critical of the comments that suggest reading up and getting more experience (I certainly plan to) but can an experienced photographer really look at a group of people in low light and dial in the optimal ISO, Shutter Speed, and Aperture to create the shallowest acceptable depth of field? It seems like the DEP setting would always produce more accurate focusing than a human being, and it would do it instantaneously. And, in the case of an impossible shot (no focus-able combination of shutter speed, aperture, and ISO), A-DEP would immediately let you know that you're wasting your time.

Ok, after hearing it for the zillionth time, you guys win. I just ordered Understanding Exposure, 3rd Edition: How to Shoot Great Photographs with Any Camera
I would love to have a Depth of Field scale on the lens itself. Ah, the good old days.

So, as I currently understand it, now that I can't fall back on the A-DEP mode, here's my best plan:

If lighting is good, close the aperture down and pray.

Or, if lighting is bad, switch to AV mode with the aperture wide open. Then see if I can get both the closest and most distant person in focus at the same time. If I can't, I'll close the aperture slightly and try again, until I figure out how much I have to close the aperture to get everyone in focus. After I figure out the largest aperture that I can get away with, I'll balance shutter speed versus ISO.

It sounds like I might be able to get an instinctive feel for this if I do it a million times but it might be a while before I quit missing the A-DEP function for quick shots.

There are depth of field charts that can also guide you. I actually have an app on my Iphone, although I've never actually used it to take a shot.

There are several Android apps that will calculate DOF.

Regardless of any of the above you will enjoy Understanding Exposure.

bohdank wrote in post #12193607
I wish they replaced the DOF Preview button with something useful like a Print button

Not bad, only one sarcastic reply!

So, you're at a concert, standing in front of the stage and you want a shot with the lead guitar and the drummer both in focus. But you don't have much light to work with so you don't want to stop your aperture down any further than necessary.

Do you have a systematic workflow that you use to quickly set your camera, or do you just wing it, relying on experience, intuition, and luck?

From what I've read here and on other forums, there are a lot of photographers who scoff and the A-DEP and scene modes but really don't know how to drive their cameras, kind of like the guy who insists on a manual transmission for icy roads but loses traction on every turn.

I took a look at your gallery, and it looks like you take a lot of the types of shots I'm talking about, quick candid group shots, and are producing great results. I sure would like to know what's going through your head as you're composing and shooting.

I'm not sure what is going through my head. It's pretty much reflexes from doing this often. If I don't have the DOF I need, I'll shoot with a wider lens which will give me more DOF for the same aperture, and crop, later. I won't go below 1/160s for concerts, and at that shutter speed, you still have to time the shot to try and capture the performer in a static moment, as much as possible. Generally I use higher shutter speeds so subject blur is not usually an issue.

Go wider and crop later, if you are depth of field challenged.

I start by setting the camera at ISO1600, f2.8, shutter 1/250s and meter on something in the lights then do the same for something in the shadows, more or less. I keep track of the difference in "number of stops". If I need more light, I'll raise the ISO to 3200. The camera is in M and stays in M. I do this before the show starts and the lighting guys are testing the lights. There is always someone on stage at this time so they are often my test subjects. I'll take a few shots, check the histogram, the blinkies and make whatever adjustments I need. I'll be chimping for the first 10 shots or so, and less so as time passes. After awhile, the whole thing becomes second nature and you get a better idea of how the histogram relates to the actual image. You will have blinkies....usually shooting into the lights so interpreting the histogram properly is important. If I need to adjust on the fly, it's usually the shutter speed, unless I start to get close to 1/160. No room using aperture, I'll switch to a prime.

Framing.. I purposely mix it up. Tight, loose, different angles. I generally have a set number of images I want to get. Once I am confident I have enough decent shots from various positions, I'll switch to primes or UW to get some more different looks and, maybe, some shallow DOF. I find that shooting from the same position, same focal length, turns out images that quickly become boring. After all, I have to go through them later and PP is not my favorite passtime.

Thanks for the compliment.

There's really very little excuse for Canon not re-implementing DEP, given the amount of computing power and (microadjustable) AF - especially with the 7D and its small spot AF ... In the Personal Function menus you could tell it what size you will be printing/viewing (if different from the old standards) and it would either give set the aperture and go to the focal plane needed, or it could calculate the several focus points/DoF combinations that would allow subsequent stacking (or even in camera preview of stacking for that matter!) for it all to be in focus in the composite. These are probably bells and whistles to be slowly rolled out as "upgrades" for new "models" when the MP war is about over

bohdank wrote in post #12195995
... Thanks for the compliment.

Thanks for the insight. That's valuable information.

bohdank wrote in post #12195995
Go wider and crop later, if you are depth of field challenged.

But then you magnify the circles of confusion anyway, ending up with the same result. Unless we assume the unlikely situation that you just crop, and sit there with a smaller image.

Remember that depth of field depends on two things only: Reproduction scale and aperture. If you accomplish the reproduction scale by using a telephoto or by magnifying when printing is irrelevant.