UNDERSTANDING APERTURE
Ever looked at a photo and wondered “how did they get that blurry background?” In short, that’s what changing your aperture setting can do for you.
In our last lesson, we talked about the exposure triangle and the three camera settings you need to use when shooting with your camera in manual mode. If you’re still a bit unsure what I mean by this, you can revisit this lesson in understanding exposure here.
1. What is aperture?
Aperture literally means "opening". In photography terms, it refers to the opening within a lens. Light travels through this aperture in the lens and into the camera body. The aperture of your lens can be controlled by you, depending on how much light you want to reach the camera sensor.
Put simply:
The wider the aperture, the larger the flow of light entering the camera.
The smaller the aperture, the smaller the flow of light.
Sometimes it helps to think of the aperture of a lens as a bit like the pupil in your eye, which shrinks or grows according to the changing light.
2. Size matters.
Aperture is expressed using f-numbers, which are more commonly known as f-stops. This is where it's easy to get confused because the bigger the number, the smaller the aperture (or lens opening). It feels a bit back to front.
When I was first learning about aperture, it really helped me to just imagine that the number actually related to the amount of diaphragm (lens blades) covering the aperture.
Take a look at these two pictures to see what I mean:
f/2 - This is a low number which offers up very little diaphragm, giving a wide aperture.
f/9 - This is a higher number which brings about a large diaphragm, giving a small aperture.
3. What is depth of field?
The size of your aperture affects the depth of field, or the area of the image that appears in focus. It’s really important to play around with f-stops and get to grips with aperture as soon as you can when learning to take photos in manual mode.
Aperture is where the magic happens. Take at look at this photo to see what I mean. What do you notice about it?
ISO:640 f/3.5 1/200
I’ve always loved looking for shapes when I'm shooting. I find that when I use a wider aperture (low f-stop), there’s less distraction. There’s less detail in focus and it’s easier to simply see the shapes in an image.
The low f-stop has affected this photo in two ways:
1. The way my little girl has characteristically crossed her ankles is the focus of the image.
2. The background is blurred but we can still make out the shape of her frame.
If I want more in focus, I might prefer to shoot with a higher f-stop:
ISO:3200 f/7.1 1/200
See how changing my f-stop has changed the mood and created a totally different type of photo?
Lower f-stops can be very emotive and the first type of image has always featured highly in my visual style. Lately though, I’m experimenting with higher f/stops more and more. I’m including more detail. It’s new ground for me and I’m really enjoying this creative exploration.
It’s a personal choice. There isn’t really a right or wrong and that’s why photography is so wonderful! It’s all about how you feel. What do you want to show with your photo? What do you want the viewer to feel when they see it?
“Photography for me is not looking, it’s feeling. If you can’t feel what you’re looking at, then you’re never going to get others to feel anything when they look at your pictures.” - Don McCullin
Pro tip: When shooting, get into the habit of asking yourself: will every single thing in my frame add something to the photo? If the answer is no, think about what you should leave out. If this can't be done by getting in closer, consider using a wide aperture and isolating your subject.
The decisions you'll make when figuring out which aperture to use is such a fun, creative part of photography. Once you get the hang of this, you'll be hooked!
4. How can I use aperture to be creative?
Portrait photographers tend to favour a wider aperture because those dreamy blurred backgrounds isolate their subjects and create a more intimate feeling.
Landscape photographers typically love using small apertures (high f-stops) because it means everything in their photos will be focus and the epic views seem to go on forever. Ansel Adams was one of eleven photographers who announced themselves as Group f/64. Every member shared a common photographic style characterised by sharp-focused and carefully framed images.
Once you understand the terms aperture and depth of field, the next step is tweaking your own aperture settings and having some fun! Can you answer these two questions?
***answers at the bottom of this post***
1. You're photographing your little one digging a hole in the middle of a busy sandpit. You want your child to be the focus of the image and don’t really need any other children to be included in your photo. What f-stop could you use?
2. You’re in the playground and want to capture the busy atmosphere and how much fun your little one is having with all their friends. There are children on the swing, some on the roundabout and some on the slide. What f-stop could you use?
5. What lens should I use?
Every lens has a limit on how large or how small the aperture can be. Take a look at your lens to find out its aperture range, it should be written somewhere on the side.
The lowest number found on your lens is much more important than the highest. A lens that has an aperture number as low as f/1.4 or f/1.8 is considered to be a fast lens. More light can pass through it than a lens where the number only goes as low as say, f/3.5. This is why if you want to shoot in low light situations (Christmas tree lights, for example), you should try to use a lens that's capable of a wide aperture.
One affordable lens capable of a wide aperture is a 50mm lens. This 50mm f1.8 is a great option. Some lenses, such as kit lenses (the one that came with your camera), won't be able to open up too wide, so you might want to think about buying a seperate lens if you really want to have some depth of field fun.
Practice Makes Perfect!
If, like me, you need to actually DO things to understand them properly, have a go at this:
Exercise
1. Line up 4 or 5 small toys on your table (toy cars, animals, dinosaurs...whatever you have to hand). Get them at different distances away from you.
2. Get yourself nice and low and slightly off-centre, so you are shooting on the same level as the toys and can see them all in your frame.
3. Set your f-stop to a nice low number. Focus on the object closest to you. Take a photo.
4. Set your f-stop to a high number. Focus on the object that it is in the middle. Take a photo.
5. Compare your photos and experiment with more apertures to really get to know how each f-stop looks.
If you’d like to share any of your aperture experiments, I’d love to see them and help cheer you on. DM me or tag @suziejaygoldsmith.
Need more help understanding exposure? Try these posts:
Click to read “The Beginner’s Guide to Understanding Exposure”
***Answers to the above***
1) A wide aperture/low f-stop to create a shallow depth of field.
2) A small aperture/high f-stop to create a deep depth of field.
P.S. This post contains affiliate links to things I am recommending, which means that if you decide to use them, I might receive a small commission at no extra cost to you.