Intro to Aperture

During this video we’re going to talk about aperture.

Understanding aperture will help you better control the light and the creativity that you can get in your photos because aperture is one of the key ingredients to helping you get that great blurred effect of the background that a lot of photographers love.

Exposure Triangle

Let’s start by looking at aperture and how it fits into the exposure triangle. The exposure triangle as you can see is made up of aperture, shutter speed, and ISO.


Today we’re going to talk exclusively about aperture and define what it is and give you some examples of what it does for you and your photographs. Let’s start by pulling up

this grid or this diagram showing you all the different aspects of aperture.   Aperture explainedIt starts by understanding what’s called f-stops. You can see on this diagram the f-stop goes from f22 and this diagram down to f1.4. A simple way to think about is the f22 is a very narrow aperture and f1.4 is a very wide aperture.  

For this video, we’re going to really take a look at aperture and define what it is and what it does for your photographs. A really important thing to understand about aperture is that it’s actually driven by your lens. This is an old 50 millimeter lens. It’s not driven by your camera. Every lens is different and every lens has a different aperture range or ability of what it can do for aperture. This old lens, taking a look at it and I’ll zoom in here close, goes from f2 to f22. I’m going to show you as it opens up, here’s f2, then f2.8, f4.6, then f6.0 as I click through them. You can see what aperture does is it’s the little thing in there that closes down how much light is let into the photograph. You can see it opens and closes based on the different apertures. That’s the first thing I want you to understand about aperture as you look back at this diagram is that depending upon what f-stop you’re at, at f22, a very narrow aperture let’s in a very low amount of light. Looking at f1.4, which is considered a very wide aperture, that lets in a lot of light. I know that these numbers, the f-stops, the light, it’s somewhat technical in nature and this is probably the most technical things that you will learn as you begin understanding photography. But once you understand aperture, it really does open up so much creativity and control of what you can do for your photograph. Even though it maybe technical, maybe a little bit overwhelming, please continue to focus on aperture because once you get it, you really will get it.

The reason I want to talk about light is it that’s the most important thing to understand about aperture is how much light it lets in. Again, f22, a very narrow aperture, let’s in a little bit of light.  F1.4 on the far end of the spectrum, let’s in a lot of light. Now, to show you a real life example of how this aperture controls the amount of light in your photograph, I’m going to use this flashlight and this old lens to show you two different f-stops and how much light is going through the lens based on the different f-stop. Let’s start with that really narrow f-stop, which is f22. You can see, it’s got a real small pinhole it’s actually letting the light through. I’m actually going to step out of lights and come into the shadows and show you what this flashlight how much light is going through this small opening at f22. Alright, so there you can see just a very small amount of light is coming through the lens based on this f22 setting. Now I’m going to take a step back and I’m going to switch it from f22 to f2, which you can see it really opened up wide, which is the wide aperture. Now I’m going to step back into the shadows, turn the flashlight back on and now you can see how much more light is coming through at f2 compared to f22 based on what this lens is able to do. Again, every lens is different. Some lenses can go down to f2 or maybe even f1.4 like that diagram was showing, all the way up to f22. Other lenses may only be able to go as low as f5.6 or f4.0. Every lens is different. A lot of times that’s what drives the cost of a lens up is the lower that the f-stop can go or the wider that the lens can get. That’s a real-life example of letting light through with aperture.

DOWNLOAD YOUR FREE E-BOOK for 10 Tips to Capture the Best Images of Your Life

FREE E-Book – Take Better Pictures

Deep Depth of Field
Aperture at F22 – All in focus
Aperture at F1.4 – Blurred Background

So now that we understand how much light is going through the lens, let’s talk about the effect that the aperture has on the photographs and this is with the depth of field. Depth of field is really just a fancy way to say how much of your scene is in focus. If you think about the depth in a scene, whether you take a picture of me and there’s a lot of trees and depth in the background, the aperture will control if I’m in focus, how much behind me (the depth of field) is also in focus. Going back to our diagram, if we’re at f22, we’re letting in just a small amount of light but the depth of field is greater. There’s a lot more in focus at f22. If you take a shot of meat f22, there’s going to be a lot of things in focus.   You’re going to see me and also the trees in focus behind me because f22 has a great amount of depth of field. A lot of things are in focus at f22. On the other end of the spectrum, at f1.4, it’s a very small depth of field. Therefore, there’s not a lot in focus. This is how you get that blurred effect. There’s more ‘blur’ in the background. With that same picture example, if I’m here and there are trees in the background, I would be in focus at f1.4 however the trees in the background would be completely blurred out because there’s just no depth of field or very small depth of field at f1.4.


Here are a couple of examples to bring this to life.

1-china-epcot-focus-backgroundHere is a shot that was taken at Epcot. This is China at night. I shot this at f14. because I wanted everything in the scene to be in focus. I wanted a lot of depth of field so you can see that the archway and the front are in focus, the building in the background is in focus. I wanted everything in focus and sharp so I shot at f14 and you can see everything is in focus, a great amount of depth of field.

1-jessie-blur-backgroundOn the other end of the spectrum, here is a portrait I took of Jessie, my beautiful bride. This was shot at f2.8 so a small amount of depth of field which allowed her to be in focus but the background behind her is completely blurred.

That’s what aperture does. Not only does it let in different amounts of light, which we showed you in those examples but it also controls how much of your scene is in focus or blurred based on the aperture. That’s what you want to learn about aperture; understanding what the different f-stops are and how it affects the lens, the light, and also the depth of field. Once you start to understand aperture, it will open up creativity for you to be able to blur the background or create a lot of depth of field when you want everything in focus and also let you control light. Aperture is the most important element in photography for your photographs.

Now that you’ve watched this video and the technical explanations and examples of aperture, I encourage you to watch the next video which is where

we’ll show you how to use it on your camera to go into what’s called aperture priority mode and start to try different things. We’ll give you some examples of the effect that it has with changing the different apertures and really put this into practice. We will go from the science of aperture, which this video was, to actually applying it by showing you what it can do and how you can use aperture priority to start practicing and learning aperture. 

Leave a Comment

Your email address will not be published. Required fields are marked *