Rare times I use Aperture Priority.

Q: YOU’VE SAID IN A TRAINING VIDEO THAT YOU RARELY USE APERTURE PRIORITY MODE. WHAT ARE THOSE RARE TIMES WHEN YOU ACTUALLY USE APERTURE OR SHUTTER PRIORITY?

A: I use Aperture Priority (Av on Canon cameras) when I’m running and gunning on a job or just casually walking the streets and shooting in conditions that change from sun, to open shade, to sun, to deep shade, to sun, to cloudy, etc.

In run-and-gun situations, like chasing a subject moving through different lighting conditions, Av or Tv (Shutter Priority) are helpful because the light is constantly changing and you may not have the time to stop and constantly dial in new settings. Photo ninja photographers can do it. You had to in the days of all-manual cameras. We get to be a bit lazy these days.

Note that I’m nearly always in matrix or average metering mode when I’m shooting like this, and my thumb is riding the exposure compensation dial. I’m always looking through the viewfinder trying to anticipate how my camera is reading the scene and I’m constantly adjusting exposure comp anywhere from +2 to –2. I do find I live a lot around +2/3 by default.

Why am I constantly adjusting exposure compensation? Your camera is metering the scene and trying to average these readings to 18% grey. You have to look at what is in front of you and anticipate how the camera will interpret that, as opposed to just letting your camera expose for what it thinks is in front of you. If you have a white girl in a white dress against a white wall, your camera wants to make that all grey, thus underexposing the scene. You have a black guy in a black suit standing against a black wall and your camera wants to make that grey, thus overexposing the scene. Exposure compensation is telling the camera to add or subtract exposure value based on whatever it is thinking.

“Okay, camera. You want to shoot this at f2.8 @ 1/125th of a second. I’m setting the exposure compensation dial to +1 so give me one more stop of light than you think this needs.” I’m in Av so I set the aperture to f2.8. The camera will then set the shutter speed to 1/60th to add a stop of light.

Basically, whenever things are on the move and the light is rapidly changing, I’m looking for the auto modes of Av, Tv, and TTL to help a brother out. Any other time, I’m on Manual for consistency. Av or Tv in unchanging light can still vary your exposures when it doesn’t need to, resulting in inconsistent exposures, thus resulting in time lost sitting on your ass in front of your computer trying to fix all the inconsistencies. Why would exposures change if the light isn’t changing? Remember that your meter is reading the scene. As you change composition or angles to your subject, your camera can be picking up different values and it will change exposures based on what it is seeing. The camera is stupid. It doesn’t realize the light on the subject isn’t changing.

Using Aperture Priority mode for portrait sessions in constant and consistent lighting scenarios bewilders me. I can’t see why anyone would do that except for the fact that they don’t know what they are doing technically, and consistency in post-production isn’t a concern of theirs.

If the light isn’t changing, exposure shouldn’t be changing. If the light isn’t changing, exposure shouldn’t be changing. If the light isn’t changing, exposure shouldn’t be changing. If the light isn’t changing, exposure shouldn’t be changing.

Lock it down and shoot. You lock it down in Manual mode. You’ll have far more consistent results and your post-production will be better.

These two shots were done in Aperture Priority mode. They are good examples of why you shouldn’t always shoot in Aperture Priority. Notice the difference in exposure in these two images. The model, Gabriella, was standing in the same spot in the same light yet when I changed composition my camera meter read different tones throughout the composition and gave me two different exposures. I imagine her white shirt was throwing one of them off quite a bit. Now then, she was standing in the same spot in the same light. Exposure on her face should be identical but the camera is stupid and doesn’t know what’s going on. You have to be smarter and take your meter readings, set your camera to Manual, and shoot consistently. If you are shooting in the same light and your exposures are going all over the place, then get into Manual mode and lock that shit down.