Living with Photography: What's Your Priority

By Norman Chan

Let's have a conversation about PASM and which modes you prefer to shoot in.

One of the first stories I assigned when we started Tested was an explainer about the shooting modes on digital cameras. You know, that manual dial on the top of most DSLRs that reads "PASM", among other icons and abbreviations. Taking your camera off the green auto mode icon and manually setting a shooting mode is the very first step to taking your camera and photographs seriously. It's also something I think many entry-level DSLR owners have probably never done. (Sony did a good job poking fun at DSLR owners who don't know how to use them in this Australian ad campaign.)

To recap, PASM stands for Program, Aperture, Shutter, and Manual. These four modes actually only adjust two settings on the camera: how wide the lens opens (the aperture) and the shutter speed. In Program mode, both aperture and shutter speed are determined automatically by the camera. It's still not fully automatic, as you can still adjust other settings like ISO and exposure compensation. But not all cameras have those customizable settings, so I treat Program as essentially an auto "newbie" mode. On the other end, Manual leaves both aperture and shutter speed open for adjustment. Finding the right balance of the two settings for different environments and subjects takes lots of practice--fiddling with one will change the requirements for the other. It's something I'm still not entirely comfortable with.

That leaves Aperture and Shutter priority. Based on my conversations with friends, most people stay in Aperture priority most of the time. I find that I'm on Aperture priority about 90% of the time when using a camera, whether it's my current favorite or a new one I'm testing. Aperture control lets you set the F-stop of the camera, opening and closing the iris to contract or expand the focal plane. In layman's terms, changing the aperture means you can set how much of a shot will be in focus, letting you get that bokeh/background defocus effect. Opening the aperture to its maximum isn't always the best solution to every shot. You let more light into the camera--meaning the shutter can be faster--but you may also lose the ability to get two objects in focus at the same time. I prefer an f-stop of around 4 for most indoor shots, and around 8 for landscapes.

Shutter priority is a little trickier. From my understanding, it's best used when you want to intentionally capture a long exposure--for the trailing taillight effect or shooting the night sky, for example--or need to shoot something moving quickly without any blurring. Because the subjects you're shooting at in Shutter priority are typically in motion, you can't gauge on the fly what to set your shutter speed at without some experience. I'd love to hear your tips for Shutter priority if that's something you have experience with.

But a big reason I'm locked into one shooting priority mode and not experimenting with full Manual is because of the the physical limitations of my camera. On my mirrorless camera, there's only one control ring on the back of the camera. The two rings on my lens are fixed for zoom and focus. The control ring on my camera is set to change aperture. Without an additional dial to quickly cycle through shutter speeds, I find that it's too clumsy to fumble around with buttons to adjust both f-stop and shutter when I need to take a quick photo. That's one of the major advantages of DSLRs over compact cameras; the value of manual dials can't be understated. It's why both the NEX-6 and NEX-7 mirrorless cameras are so popular, and something I'll be taking into consideration when looking at a DSLR purchase.

And as I mentioned last week, here's a favorite recent photo I've taken. This photo was snapped at the Museum of the Moving Image in Brooklyn, New York during our trip there for MakerFaire New York. Still working on setting up a Tested Flickr pool, which makes more sense now that Flickr users are flocking back to the service with the release of its new app.

Sound off below with your thoughts on Aperture vs Shutter vs Manual modes and which ones you prefer.