Guest post by Justin McKee
Over the past few posts of mine, we’ve discussed shutter speed, aperture and ISO, as well as how each of these photographic settings individually contribute to a final image. The discussion has even touched on how all three of these settings work together (and against each other) to create a photograph.
To help you, the reader, have an even greater understanding of how these settings correlate, I’m going to use this post to give some real world examples of what settings to use in differing situations.
Before we get started: If you’re using a DSLR (or point-and-shoot that has manual control), the same light meter inside your camera that measures the light coming into your camera is still available to you in your viewfinder if you’re using automatic mode. The light meter looks like this: -2..-1..0..1..2. There’s a little arrow below the numbers that changes position as you change shutter speed, aperture, and ISO. Basically, if that little arrow is on 0 your picture will be perfectly exposed; not too dark or too light. If the arrow is higher than 0 the picture will be too bright, and if it’s below 0 the picture will be too dark. This is a great feature, use it well and often.
First, we’ll travel outside. Even on a cloudy day there’s far more light (generally) than indoors. A park is a great place for candid outdoor photography and an excellent example for taking photos of subjects on the move. Let’s say we’re taking photographs of cyclists or joggers down a trail.
Because there’s so much light outside, using an ISO that is around 100 or 200 is perfect. It’ll create a nice and clean photograph without slowing down the shutter speed too much. If you’re in the shade and need to use a higher ISO to get a fast enough shutter speed to stop subject motion, go for it.
For shutter speed with moving subjects, if you want to stop motion, you’ll want a shutter speed above 1/500th of a second. You can get away with slower speeds in some instances, but you might see small hints of blur otherwise. It is possible to take pleasing photos of moving subjects with slower shutter speeds. If you follow your subject with the camera as they’re moving parallel to you (with a slow shutter speed of 1/60th of a second or so) it will create a very pleasing background blur while the subject stays in focus. This technique is referred to as panning.
Deciding aperture for moving subjects outdoors is easy. If there isn’t enough light to use a smaller aperture (meaning, your ISO and shutter speed will suffer because you’re not letting in enough light through the lens), just set the aperture as wide open. Doing so will create a pleasing background blur in the photograph. There’s a higher chance of your subject being out of focus because of the limited depth of field, but your shutter speed should be fast enough to stop subject motion because you’re allowing more light to enter the camera.
For the next scenario we’re staying outdoors, but this time we’re shooting a more stationary subject. Let’s say we’re outside at the park still, but this time we’re shooting portraits. Generally the subject, wherever you place them, stays stationary.
For ISO we’ll stick to 100 or 200 again because of the amount of light outdoors. Even in the shade this should be okay because with a stationary subject a fast shutter speed isn’t completely necessary.
A shutter speed as slow as 1/60th of a second can be used here because of how still the subject will be. Granted, there may be too much light outside to get a shutter speed that slow, but that’s OK. You may want to avoid a shutter speed that is too fast, however, because you’ll be decreasing how long your sensor is exposed to the light outside which can negatively impact your ISO and aperture.
With portraits you’ll want an aperture that is wide open. If you can get an aperture below f/4 you’ll have a beautiful background blur depending on how zoomed in on the subject you are. For portrait photography, a wide open aperture is excellent because it helps isolate your subject in the photograph.
Let’s travel inside for this last scenario. If you’re indoors and there aren’t many lights or windows to work with, you’re going to have a completely different setting scheme for shooting. The same settings can also be used outdoors during the evening hours when there’s very little sunlight left in the day and/or there’s only ambient light coming from street lamps or local businesses.
It’s raining outside and your teenager is about to head out to his or her first dance. You want some photos, but you’re not overly fond of getting soaking wet in the rain and frankly, neither is your nicely dressed teen. You opt to take the photographs inside the house, but there is far less light than you were expecting.
That’s OK though. For ISO you may need to crank it up as high as 1,000 or even 2,500. The noise will definitely be there, but you’ll need your sensor to be able to gather enough light for a decent shutter speed. Using a flash can help lower ISO drastically because you’ll be creating new light, but that’s a whole other post.
A slower shutter speed is admissible in this scenario because your subject is stationary. If you use a slower shutter speed, you can use a lower ISO, which will help make a cleaner photograph; ISO and shutter speed in these situations are the priority because there is so little light that you’ll pretty much have your aperture set as wide open all the time.
Indoor shooting can be tricky because of the lack of light. A tripod can help; so can a flash if it’s appropriate to use one. It’s important to do test shots before the actual shoot so you know what settings are best. Plan ahead and you’ll be in the clear.
These are just a few examples of how all three settings work together and/or against each other when exposing a photograph. Other posts will feature more scenarios that can help increase understanding, but the best practice is to practice.
In my next post I’ll discuss something called “white balance.” Ever had your photographs turn out really orange or blue? There’s a way to fix that.
Justin McKee is a small-town photographer with big ideas living in Michigan. In addition to portraits, wedding photography and video, he also enjoys wildlife photography. He always seeks to learn more about his craft.