Homemaking, Motherhood

Taking Pictures of Your Kids: exposure

Taking pictures of your kids – easy, right? Not always. When you have a nice camera but don’t really know how to use it, the gap between expectation and reality can be frustratingly huge. Bouncing off of last week where I talked about framing photos of your kids for maximum impact, here are some tips for how to make your camera work for you instead of turning you into a crazy person.

Exposure can be super confusing and frustrating if you don’t have a basic understanding of it. There’s nothing more annoying than getting what you think is the perfect shot, only to realize that it’s super dark or super bright or – the worst of all – blurry!

This is meant to be a quick overview of the three basic parts of exposure: shutter speed, aperture, and ISO. The best description I’ve ever read about exposure was that it’s like a window. Shutter speed controls how long the window is open, aperture is how wide the window is open, and ISO is how tinted your window is. The window’s goal is to let in light – those three elements work together to give you a bright, clear photo (hopefully!). Think of them as a triangle; when you shorten one side of the triangle, you have to adjust the other two to compensate.

I once again took photos of my kids playing outside to try to get some good examples. I have no idea what my son got into, but his face is filthy. I promise, I do bathe him.

Shutter speed
Just like it sounds, shutter speed is how fast your shutter opens and closes. If you are taking pictures in a dark room, you’ll need a slower shutter speed in order to let enough light in to get the picture. Examples of shutter speed are 1/15 (1/15 of a second), 1/60, etc. The downside to a slower shutter speed is that it captures everything it “sees” while the shutter is open – which means if you’re taking a picture of a moving child with a slower shutter speed, they will be blurry in the photo. The faster the better, if you’re capturing motion. On a bright, sunny day outside, you can set it really fast (1/200, for example) and get the toddler running past you with no problem.

Shutter speed: 1/100 – pretty fast so no blur, but didn’t let in much light.
Shutter speed: 1/20 – it let in a lot more light, but you can see how blurry she is. All other settings remained the same.

Most cameras will have an option to control your shutter speed and let your camera decide how to compensate with your aperture and/or ISO. For example, on a Nikon, set your dial to “S” which stands for “shutter priority”. A Canon will have “Tv”. When your camera is set to shutter priority, you can choose what your shutter speed is and your aperture will be automated (you can set your ISO to auto, but I don’t recommend it… we’ll get to that in a second).

Aperture, simplified, controls how wide open the hole in your lens opens. This is the confusing part: a high number indicates a low aperture, which means a smaller hole. Smaller hole = less light. The trade off is that a smaller hole gives you a deeper depth of focus, which means more of your photo will be in focus.

It sounds super complicated, I know… but it doesn’t have to be.

Aperture is measured in f-stops. So when you see numbers like f/16, f/4, or even f/1.4, those are referring to aperture.

A high aperture like f/1.8 means you have a very large hole to work with. You’re working with a lot of light! (What does this mean? A faster shutter speed is okay, so low apertures are nice to work with your fast-moving children.) BUT, you don’t want to shoot much more than one person if you are working with this high of an aperture, because not much is going to be in focus. The closer you are to your subject, the more you’ll see evidence of this. If your focal point is pretty far away from you, you’ll still get a decent amount in focus at f/1.8.

Aperture: f/2.8 – pretty high. A lot more light is allowed in, but see how the door and grass in the background are totally out of focus?


Another example of f/2.8 – my son was closer to me when I was taking this photo, so the background is even more blurred. This is called a shallow depth of field, which is fantastic for portraits.

A low aperture like f/16 means you have a smaller hole that your camera is shooting through, so you get less light. (Which means you may want to pair it with a slower shutter speed to make up the difference – see how they work together?) When you take a picture at f/16, pretty much everything in your frame will be in focus; it works well for large groups of people and landscapes.

Aperture: f/10 – a smaller hole. It let in less light, but you can see how the door and grass behind him are in focus. I actually had to make my shutter speed much slower for this photo (from 1/200 to 1/50) so that you could even see him, which shows how powerful aperture is.

To set “aperture priority” on a Nikon, set the dial to “A”. On a Canon, set it to “Av”. Then you can choose the aperture you want to work with and your camera will “auto-fill” the rest. I have a lens that I love that is capable of f/2.8, and I generally keep my camera on aperture priority set as high as possible. I prefer to sacrifice the background of my photos being in focus in favor of no blur.

When you are purchasing a lens, the highest aperture it’s capable of achieving is denoted in the name of the lens. For example, my favorite lens is a Tamron 28-75 f/2.8. The 28-75 indicates the focal lengths it can accomodate, and the f/2.8 is the highest aperture it can achieve. That’s something to look for when buying a lens.

ISO is how tinted your window is, remember? It’s a way to lighten or darken your images. A lower number indicates a darker image (not “helping” your camera brighten it, essentially) while a higher number is better to use in a dark situation to help offset a fast shutter speed (so your subject isn’t blurry) or a low aperture (to get more in focus). Cameras usually range anywhere from 100-1600, with 100 being preferable. Why is it preferable? Because the higher that number is, the more “noise” you’ll have in your images, meaning they turn a bit grainy. I can comfortably turn my ISO up to 1000 on my camera without too much visible grain, but if I have to go to 1600 (like in a very dark room or outside at night), I know I’m not going to be very happy with my results.

Changing your ISO can be different on different camera models, so I recommend looking at your manual or the internet for instructions on how to do that.

Almost all the photos I took above were at ISO 100 because we were outside on a beautiful, sunny day. I took the kids inside and shut all the windows to try to simulate a dark environment.

They sang me a song as I tried to take their picture. This is basically as good as it gets around here.

The ISO is set to 1600 in that photo, and you can kind of see the graininess but not totally appreciate it. I cropped both this one and one with ISO 100 so you can see a comparison:

If you are planning to enlarge a photo, a low ISO is especially crucial!

Hopefully all of that made sense. Please feel free to reach out with any questions I have not have answered… or questions I created. 😉

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