episode 44

Back to Basics: The Exposure Triangle

Hey everyone, this is Jordan from Sleeklens.com and welcome to this episode that’s going to be all about the basics when it comes to photography. Now I covered an episode like this a long time ago where I basically talked about, kinda, what the shutter speed was because it was really a needed question that came from a listener of this podcast who was just getting started with photography. So, actually over the past week or so I’ve got a lot of questions on how to move from Automatic Mode on your camera. And so, I thought about there are easy ways to do that, but the easiest way is to understand the Exposure Triangle. I’m quickly going to cover the ISO, the Aperture and the Shutter Speed, exactly what those mean and how do they affect your photos.

Shutter Speed

Alright, so let’s talk about the easiest one first. The easiest one to understand, in my opinion, is Shutter Speed. So, obviously, the first thought that comes when you hear shutter speed it means how fast something is moving. In your camera, in most cameras, there’s what’s called a curtain. A curtain basically reveals the scene to the sensor that’s in your camera; the sensor is actually a piece of equipment in your camera that captures the data, captures the scene that you’re looking at. And so, it will reveal the scene like a door that opens and closes. Now, if you were to open the door and reveal, let’s say somebody running down a field, if you’re going to open that door and you really want to freeze them you have to make that door open and close very, very fast. That means you’re freezing the motion of somebody, which also applies to a car wheezing by very fast, that’s how you freeze somebody in action. Very, very fast shutter speed, and shutter speed is represented by a fraction number on the back of your camera. So, if you see 1/100 that means it’s 1/100s the timespan that the door is opened and closed, revealing the scene. That fast shutter speed will let in a lot less of light – a topic which we’ll cover later on – but that will allow lot less light and it will freeze the motion that’s there.

That’s a quick way to freeze somebody. If you want to freeze fast-moving subjects, you’ll have to use shutter speed values around 1/500s, but you’ll need more light. So, let’s go into that part as well. When you’re talking about letting in more or less light, photography is all about light. You need light to see a scene, so if we take the example of that person running down the field and use 1/500s as shutter speed, we need to make sure we have a lot of light. If you’re doing this during the day, most likely you’re going to be fine because the sun is really bright outside, there’s obviously a lot of light coming in so probably getting 1/500s as shutter speed is fairly easy; but let’s say you’re inside, you are in the living room or something like that. You can technically set your camera to that shutter speed, but most likely – unless your other settings were made accordingly – you’re not going to be able to get enough light to come into your camera. Your picture will probably look just black, no data is going to be recorded from that scene. That’s the very long explanation of what shutter speed is but, basically, if you were to have a very fast shutter speed and you want to freeze motion, freeze somebody jumping in the air, and you have a shutter speed of 1/30s or 1/5s you’re actually going to show motion. If you want to have the waterfall or water running that we always see in landscape photos, if you want to have that scene, if you want to show the motion of the water set your shutter speed to longer shutter speed.

Okay, so that were the very basics of shutter speed. Obviously, there are a lot of things when it comes to shutter speed, so that were the bare basics of it.

ISO

Now let’s jump into another section of the exposure triangle which is ISO. This is probably going to be another easy one as well.

So, ISO is an acronym for International Standards Organization, and what that means is basically an organization that sets the sensitivity of things – which is kind of a boring job if you ask me 🙂 – but the ISO in the camera sense is actually the measurement of how sensitive your sensor is.

You’re going to see in the ISO settings that the value is probably set to, let’s say, 100. That’s probably going to be on the lower end of the spectrum, which means that your camera is not going to be as sensitive to light as it would be if you set it to higher values. So, the values for ISO are usually set to the double of that value, it goes like 100, 200, 400, 800, 1600, 3200, 6400, and so on. Usually, in an entry-level DSLR you’ll see that doubling of the amount, and as you double that amount your camera is more and more sensitive to light. ISO 100 is not very sensitive to light at all, which is useful for scenes that are very bright; in that scene of the person running down the field, the value is helpful if we talk about daylight conditions. You don’t need your camera to be sensitive to light as you already have a lot of light around.

On the other hand, if you are in that indoors situation, you’re going to need to have more light in your camera, so, you want to take your eyes in bump it up. Maybe bump it to 800 or 1600, or higher. What that’s doing is making your camera sensor more sensitive to light, so that way you can properly expose your scene: it’s not either too dark or too bright. So, a lot of people actually ask when I talk about ISO why not keep your camera at a high ISO all the time? Because that way you wouldn’t have to worry about settings, setting your ISO whenever you’re going to take a picture. Well, there are drawbacks when it comes to setting your ISO up fairly high, when you start setting the higher numbers. The main thing is that you actually introduce noise into your scene. Noise is something a lot of people see, and it’s actually a grain – I don’t know how to explain it – it’s kinda like a great pixelization I guess. We all know what digital noise is, some people say their images are too noisy, and they are not talking about audio noise but digital noise where you can see a lot of grain in your images.

Now, one way to have this explained to a lot of beginners – and this is a way I actually heard it when I was learning about the exposure triangle a long time ago – is to envision the noise in your camera like the noise you would hear from the microphone that I’m talking right now. So, right now I’m talking at a fairly nice, a nice distance away from the microphone – maybe 6 inches away – and my voice is fairly clear. This would be considered ISO 100: a very clean image, like the very clean sound that’s coming from my voice. But if I were to go closer to the microphone – like this (shows in audio) – it’s a lot noisier. Obviously, it’s not going to sound really well when I get close to the microphone, and that would be considered a higher noise. It’s moving the audio distortion in this file you’re listening to, but when it comes to an image it looks pretty grainy. That’s the reason why you don’t want to set your ISO to a higher ISO all the time, because you don’t want to introduce that noise in your image if you don’t have to. You can always use Photoshop or Lightroom (or similar) to reduce the amount of noise that the higher ISO value creates, but obviously higher amounts of noise cannot be completely removed.

Aperture

Finally, let’s talk about Aperture. Aperture is the setting that a lot of people struggle with because they know the effect they want to achieve but they don’t know how to achieve it with the aperture and also compensating for all the other elements out there. So, let’s talk about aperture really quick.

First of all, aperture is, basically, the opening and closing of the inside of the lens, which allows more or less light into your camera. And this is usually represented by an f-number on the back of your camera. So, you might see f/8, f/4, f/2.8, f/22 – something like that. Those are all values of how open and closed the blades inside your camera are, to let in more or less light.

One of the trickiest elements when it comes to this is what does this number represent. So, let’s say you have your camera set to f/22. It’s a very, very high aperture, and what that means is that the opening, when you take a picture, when you snap a picture, is a very, very tiny hole. And this is going to let, hardly, any amount of light into your camera. This means that you have to be in a very bright situation – again, a very bright day – to shoot between f/18 – f/22 means a very small hole and less light in your camera. Now, if you were in that same sunny scene and you change your aperture to, let’s say f/4 – all the way to the other end – when you snap the aperture will close down hardly any. It’s going to be a very large, wide opening. So, basically the smaller the number the larger the hole that’s in your camera when you take the photo; the larger the number the smaller the hole it’s going to be. It’s very tricky but you kinda get used to it when you start taking photos.

So, f/4 or a small f-number let more light into your camera, this is good again for those dim situations, those indoor situations maybe or night situations. It will let in more light to your camera, and again, photography is all about light. To get as much light in your camera to expose your scene properly. But aperture also affects your photos in another way: this is the hardest part for people to wrap their mind about – we talk about Depth of Field (DOF)

Depth of Field is, basically, how much of your scene is in focus either behind or in front of your subject. So, let’s say you’re taking a picture of a portrait of somebody, and you really want to have that blurry background that you see a lot in those professional photos. You really want to get that really blurry background while also keeping your subject in very sharp focus. The way you can do that is – and I’m taking about very basic parameters here – to set your aperture to a lower f-number. Maybe do an f/4 – f/5.6, something around there – and what you’ll do is focusing on your subject and you’ll see that the background is very, very blurry – very blown out. Something like that soft bokeh effect many people desire. In front of your subject it’s going to be blurry as well if you use that setting, so, this is useful if you are shooting a subject and the background is blurry and maybe have some flowers or something like that. If you were to set your aperture to a higher number, let’s jump up to f/22 again, if you have those flowers in the foreground your model, and the middle and background are not going to be that blurry, you’re not going to get the same effect. The background may still look a bit blurry, but nowhere near when using low aperture values.

If you’re working with portraits and you desire a blurry background you really have to stick to low f-numbers. If you’re shooting something like Real Estate, maybe landscapes or something like that, you kinda want that higher f-number depending on what you’re shooting. With a higher f-number you take more of the scene in focus.

So, going back to the original question, how to move from Auto-Mode to Manual, the easiest way to hack this little thing is if you go out on a bright day – pick a really bright sunny day – and I’m going to give you some settings for your camera to see if you can get a really decent photo.

ISO: 200

Shutter Speed: 1/200s

Aperture: f/6 – f/7.1

Now, go outside and take some photos. What you are going to see, depending on the situation obviously, is an image. It’s up to you to dial in that image.

Let’s say that you went and take a picture with those values and the image is very, very bright. You have a couple of things you can do.

If you want to take an image and give it a little less brightness you can do three things:

  • Bump the ISO down to ISO 100 – That’s going to make your camera less sensitive to light – it will basically cut your lighting conditions by half.
  • Take the Aperture value up to, let’s say, f/11, or something along those lines. You’re going to see that your image looks a bit darker if you take another shot.
  • You can increase your Shutter Speed, that’s going to let in less light through the camera.

In the case with the given original values the image turned out to be too dark, here’s what you can do:

  • Try with ISO 400. You’ll get in more light but depending on how dark it was you may need to increase the value even more.
  • You can also decrease the f-stop number. Say f/4, some lenses even go down to f/2.8. By doing so you’re allowing more light to come into the sensor.
  • You can take the Shutter Speed and decrease it by half, to 1/100s, that will let in more light.

So you can see that what I’m doing is to compensate for the amount of light that’s available in your image. That’s the procedure for those who are in trouble and need to learn how to expose right in manual mode. Some people may stick to Auto Mode and say that Auto is great, but when you get to do all these settings you’re going to be able to experiment more with your scenes.

If you want to learn more about the basics of photography we actually have a course on Photography for Beginners, where we talk about the exposure triangle and way even more data that will certainly teach you how to migrate to manual mode.

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