How Does A Camera Work? Just The Stuff You Need To Know! And also some more thoughts on the last episode, erm 11 Actionable Things You And I Can Do To Improve Our Photography in 2023 – Part 2.
Hi and welcome to Episode 150 of the Photography Explained podcast. I’m your host Rick, and in each episode I will try to explain one photographic to you in plain English, in less than 27 minutes (ish), without the irrelevant details. What I tell you is based on my lifetime of photographic experience. And not Google. OK there was a bit of Google in this one.
First - here is the answery bit
A camera is a light proof box with an opening in it, which opens when the shutter is raised to allow light to pass through to the camera sensor. Or film. This is what happens when you take a photo.
That was the answer. In this episode I will explain this all in a bit more detail, just enough to help you and I of course. Right – let’s get straight into the talky bit.
The talky bit
I answered this question way back in episode 2, but there is no need to go back as this is a much fuller answer.
Where does the word camera come from?
In episode 2 I wrote this.
“The word camera comes from Camera Obscura. Obscura is a Latin word that means darkened in English . Camera is also Latin, meaning vault or vaulted room. It also has Greek origins as well.
So camera obscura came into being and that means dark chamber. So there you have it - next time you look at your camera, think of it as dark chamber!”
OK – that was then. But there is more. Camera obscura is actually a natural thing that happens when light is projected through a small hole onto say a wall.
And this is where the pinhole camera came from, a smaller version of the camera obscura. Yes this is a massive oversimplification of the history of a camera, but the point is this.
A camera is lightproof box with a hole in it.
There, I am happy with that. Sometimes when I am writing this stuff I worry that I am not explaining things, but I am quite happy with this.
What is the difference between a pinhole camera and a modern camera?
In principle nothing. They are both lightproof boxes with a hole in them that lets light in.
Why a light proof box?
Well, rather than viewing the image on a wall, some very clever people worked out that you could record that image by very clever chemistry. But to do that you needed to be able to control the amount of light that got through. Take that all the way to today and that is what the shutter is doing – controlling the amount of light that hits the sensor.
So that is the shortest history of the camera ever, but it makes sense to me.
That is how a camera works. You compose, focus, apply the settings that you want, and when you press the shutter release button the camera sensor is exposed to light, and the image is recorded on the camera sensor.
How does a camera sensor actually work?
A camera sensor captures light and converts it into something that becomes a photo. I am sorry, this is way beyond my comprehension and understanding.
I have read various explanations of how a camera sensor works, and concluded that I am not intelligent enough to understand this.
And understanding this will not help me with my photography. No this is a level of complexity and detail too far for me.
So I stick to my explanation.
A camera sensor takes the light that hits it when the shutter is opened and turns it into a photo. That will do for me.
And camera film does the same, just using a different process.
OK let’s move on.
Why is a camera the shape and size that it is?
Evolution. Quite simply. Another massive leap in time and technology now. In the early 1900s, yes, all that time ago, 35mm cameras started to be made. The SLR camera is a direct evolution of the 35mm camera.
SLR cameras, which were known as 35mm cameras, used 35mm camera film. The size of the photo recorded on the camera film is 36mm wide x 24mm high.
And guess what – the size of a full frame camera sensor is 36mm wide x 24mm high!
This is where the size of camera sensors today came from.
And that is why a camera is the size that it is, it is all based on the camera sensor, the important bit that takes the photo.
And the rest is about us humans and how we use the camera.
Talking of which – the parts of a camera
Viewfinder
This is the thing that you look through to take a photo. These days you can also do this using the LCD screen on the back of the camera. I am more a traditionalist though, so I still use the viewfinder first.
There are optical viewfinders, where through mirrors and string and stuff you actually look through the lens, and electronic viewfinders, aka EVFs. Well it is too much to ask to say the actual words right, so let’s abbreviate that!
You will find an EVF on a mirrorless camera, and an optical viewfinder on a DSLR camera.
Same but different.
Same as in you press the shutter release button and you take a photo. Different as in exactly how they do this.
Other bits of the camera
There are cameras with fixed lenses and cameras where you can change the lens. There is an acronym for these cameras, ILCs, or interchangeable lens cameras. If you have ever wondered what this term means wonder no more, it is confusing and does not help us.
So there are cameras with the lens fixed to the body so that is that, and there are cameras where you can change the lens.
You can change the lens on most cameras, so that is what I will go with here.
There are two parts to most cameras, the camera body, and the lens. The camera body houses all the electronics, the camera sensor, batteries, memory card slots, and all the dials and controls that we need to change the settings to take photos.
The lens contains the optics, and is the thing that focusses the light on the camera sensor.
Lens mount
The lens mount is the thing that you attach the lens to the camera body with. Each manufacturer has their own lens mount – you can put a Canon lens on a Sony camera. The exception to this is micro four thirds cameras, which all use the same mount.
There are what is called third party lens manufacturers, who make lenses for more than one camera system. Blimey, that is camera lenses explained in a nutshell!
Photographers use different camera lenses to take photos of different subjects, and in different conditions. That is an episode all of its own for sure. And I have just added that to my list.
Grip
Important this. The camera grip is, not surprisingly, the bit that you use to hold the camera. As you look at a camera is it the sticky out bit on the left hand side, which when you hold the camera to your eye is the right hand bit. Yes camera manufacturers assume that we are all right handed. What do you do if you are left handed? I am not sure to be honest.
The grip is very important, as this is what you hold the camera with to take a photo.
Camera settings
There are a seemingly endless array of buttons and dials on cameras these days. These are the things that you use to change the camera settings. Don’t worry, you don’t have to use them all, all of the time.
But there are the three main things that you do need to know about, aperture, shutter and ISO. These three settings determine if you get a photo that is correctly exposed. Correctly exposed means that you have recorded the levels of light in what you are photographing correctly. This too is very important.
The exposure triangle is the combination of the three things.
Aperture
The aperture is in the camera lens and not the camera body. The aperture is the hole that light passes through when the shutter is opened. You can change the size of the aperture, making the opening
- smaller, letting less light in, or
- larger, letting more light in
Shutter
The shutter is normally closed, and when opened exposes the sensor to light. The amount of time that the shutter is open will determine how long the camera sensor is exposed to light.
- A faster shutter speed exposes the camera sensor to less light
- A slower shutter speed exposes the camera sensor to more light
ISO
ISO is the now baffling term for the sensitivity of the camera sensor to light. Forget the history, this is the important bit
- The lower the ISO number, the less sensitive the camera sensor is to light
- The higher the ISO number, the more sensitive the camera sensor is to light
What does this mean? Simply, if you take a photo with a low ISO, say 100, if you then change the ISO to say 400, the camera sensor is more sensitive to light, and the less light that is needed to give the correct exposure.
These three settings work together to give you the correct exposure for a photo.
Manual or auto
A camera will allow you to set the three things above manually, or it will do this for you. Or you can set two of these and it will set the other. But this is all stuff for another episode. I am talking here about how a camera works.
Where are the photos stored?
Cameras have memory card slots. You insert a memory card into the camera and this is what the photos are stored on. You take the memory card out of the camera and import the photos to a computer.
Tripod thread
I just want to mention this – the tripod thread. On the bottom of a cameras body is a thread, which you can attach a mounting plate to, and then put your camera on a tripod with. These threads are all the same size.
Why would you do this? Another one for another episode.
Batteries
Sorry, camera batteries. You will need these to make your camera work. All cameras use rechargeable batteries.
Other good stuff
There is lots of other good stuff in cameras, I couldn’t possibly cover it all in one episode. And every camera manufacturer has different things and different ways of doing things. But the stuff that I have told you here applies to the vast majority of cameras.
Right – talky bit over - what if I use a phone and not a camera?
Well a phone is a device that you can use to take photos.
A phone has a camera lens, a sensor, and everything else is built into the phone. But the basic principles apply, compose, focus, take a photo. It is just done in a different way with a phone. You just don’t have all the adjustments that you do with a camera. And that is a good thing and also a bad thing. It just depends.
It is a good thing as all you have is your phone, all nice and simple. And bad because you don’t have all the other adjustments and stuff that we photographers get with cameras. Which again can be seen as good or bad.
What do I do?
Me? I use all of the above, of course I do. I use a camera to take my photos. I have a small number of camera lenses that I use. I know my camera inside out. And this is the thing that I want to expand on here.
I have learned my camera inside out. I have spent time to practise and learn with my camera. And I have set it up so it works for me.
There are a lot of things that you can change in a camera, there are settings that you change for every photo that you take, and settings that you make once and never go back to.
But you need to know what those camera settings are, and make sure that you set your camera up to work for you.
How does a camera work? Well out of the box how the manufacturer has set it up. But this might not be right for you. So to get your camera to work properly for you, you have some work to do.
How does my camera work for me? Well these are the things that I have set
- AV Mode
- ISO100
- F8
- RAW Image capture
- Camera on a tripod
- Self-timer on
- Auto-bracketing on
See there is so much to this, these are just the headline settings, and auto bracketing gets a mention for the first time here! Very quickly, I use auto-bracketing, where the camera takes three photos at the same time, but with different exposures. I merge them together in Lightroom later to create one image to work on with more of the lights and darks than I would get in a single image capture.
Some thoughts from the last episode
“11 Actionable Things You And I Can Do To Improve Our Photography in 2023 – Part 2”
Well, I don’t want to go on. But I will. The number one way for you and me to improve our photography is to go out more to take photos but take less photos. Quality over quantity. Think about the photos that you are taking when you are doing it.
Enough said.
Next episode
Episode 151, How Do I Take The Best Photos That I Can With My Camera? This is the logical next episode, where I take what I have told you about here, and tell you how to take the best photos that you can.
And now some stuff for you to do
First off, if you have a photography question you want me to answer in plain English, in less than 27minutes (ish) but still without the irrelevant details, just head over to PhotographyExplainedPodcast.com/start where you can find out what to do. Or just say hi. It would be lovely to hear from you.
And a favour
If you enjoyed this episode please write a nice review on your podcast provider of choice. And post it on your social feeds. And why not follow my podcast to make sure you get the next episode when it is released?
That’s all.
This episode was brought to you by, erm, well breakfast as I am recording this one in the morning which is most unusual! So no cheese and pickle sandwich and a bag of salt and vinegar crisps all washed down with a Diet Pepsi, not yet, that will be later. No, I have just had a nice coffee before I settled down in my home-made, acoustically cushioned recording emporium.
I’ve been Rick McEvoy, thanks again very much for listening to my small but perfectly formed podcast (it says here), and for giving me 27 ish minutes of your valuable time. Yeah I think that this episode will be 27 minutes long.
Take care, stay safe
Cheers from me Rick