By Charles MacPherson–
Beginner’s Corner – Exposure Modes
I’ve been asked to explain something about the different exposure modes. I’ll go more into depth on these next month.
Here are the modes that most cameras have:
Green Box or Full Auto. The camera controls all exposure and autofocus (AF) settings. You have zero control, but will usually get an acceptable image.
P or Program. Generally the same as Full Auto, except that you can change your ISO and decide whether to use your pop-up flash.
A or Av – Aperture Priority. In this mode, you select the aperture and the camera sets the corresponding shutter speed.
S or Shutter Priority. Just the opposite of Aperture Priority – you select the shutter speed and the camera sets the corresponding aperture.
M or Manual Exposure. You start by selecting either the aperture or shutter speed – whichever you prefer. Then, using the other control, you adjust it until the pointer on the camera’s meter points to the “0” position.
A-Dep. A Canon-only feature that looks at all of the active focus points that have achieved focus lock. It then sets the aperture needed to try to make them all in focus through the use of depth-of-field.
Scene modes. Like Sports, Portrait, Macro, Landscape, etc. By telling the camera what kind of scene you’re shooting, it uses presets that the manufacturer thinks make sense.
With those definitions out of the way, how do you decide which to use and when? It all depends on the kind of shot you’re after.
Here are some *very* general guidelines – and you should feel free to season to taste!
As you look at a scene, ask yourself “what’s most likely to go wrong with this shot?”
If your answer is that you’re worried about motion blur wrecking the shot, try Shutter priority, setting the shutter speed to whatever you think you’ll need to freeze motion.
If your answer is that you want a de-focused background or foreground to avoid them distracting from the subject, try Aperture Priority and set the aperture to the smallest F-number.
If you’re just after a few quick snapshots, (or if you see Bigfoot walking out of a 7-11 and getting the shot is more important than fine-tuning it), try either Full Auto or Program.
Scene Modes? Use them if you wish, but you won’t learn much this way. I suggest starting in a scene mode and taking note of what the camera suggests for settings. Try them, but then try changing things up a bit. That will help you to understand more about what’s really happening with the camera’s controls – and how you can take charge of them yourself to make them do what you want.
When should you use Manual mode? Almost never, unless you’re an advanced amateur or professional. It’s useful if you’re tracking a moving subject that’s transitioning between light and dark backgrounds that will fool the camera. But in this case, you’ll need to know how to expose the subject (not the background) and lock that exposure in. That’s where Sekonic Incident Light Meters come in handy!
Next month, I’ll talk about the settings I actually use. And I use only ONE exposure mode over 90% of the time.
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