Hi everybody, welcome to Episode Two of the Photography Explained Podcast. In this episode, I will explain this – how does a camera work?

I’m your host Rick and each week I’ll try to explain one photographic thing to you then in less than 10 minutes.

Okay, so how does a camera actually work?

A camera is a lightproof box with an opening in it which allows light to pass through to the sensor where the image is recorded. The camera body is the box, the lens is the opening and the shutter is the thing that opens to let the light in. The lens focuses the image on the sensor giving a high-quality recording of the scene the camera is pointing at.

A camera works by exposing the camera sensor to light when the shutter opens. The amount of time the shutter is open, the size of the opening in the camera lens and the sensitivity of the camera sensor to light are all adjustable and set by either the camera or the photographer to create the exposure.

This is not what I said in the podcast, but is a much better answer.

You can listen to the episode here

Or keep on reading. Or do both. Entirely up to you!

What is a camera then?

Well, 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 a dark chamber!

It all makes sense, doesn’t it? A dark chamber can become a lightproof box.

How does light get into the box?

The lightproof box has an opening in it which is called the shutter. When the shutter opens light gets into the lightproof box where the camera sensor is.

So that’s the fundamental of this

Okay, let’s have a look at the fundamental components of a camera.

I’m talking about a conventional camera with a camera lens on a camera body.

Camera body

The camera body is the bit that has all the electronics and clever stuff in it. It also has such things on the camera body, controls and dials with which we can change all those many, many settings.

Camera lens

The lens to attaches the camera body by a mount. The lens is the thing that controls the light and the sharpness of the light getting in (not what my transcript says so time to correct this!

Camera sensor

The camera body is where the very important sensor is. Now what’s a sensor? If you think of a film camera (if you’re old enough) there was a place where you put the film, in the back of the camera body. You had to wind the film onto the first bit to take a photo with It.

Well on a modern camera, the sensor is where the film was in simple terms.

Camera shutter

The shutter is the thing that lets light reach the sensor. Press the shutter release button and the shutter opens, exposing the camera sensor (or film) to the light coming in through the lens.

Again, I don’t want to get too technical here!

So a camera is a light-proof box with a shutter in it.

So how does the light get onto the sensor?

Well, the next thing is what’s called the camera lens which is either attached to or built into the camera body. On conventional DSLR and mirrorless cameras, you can change the lenses. There is a very unhelpful acronym ILC which means interchangeable lens camera. To be perfectly honest with you I don’t see the point of that.

The camera lens has all the optics in it to focus what the camera is pointing at onto the sensor (or film).

The other thing that the camera lens contains, as well as the optics, is the aperture.

In most cameras the aperture is adjustable, meaning you can change the size of the opening in the lens which reduces or increases the amount of light getting through to the camera sensor.

Shutter and aperture – the special relationship

There is a relationship between the shutter and the aperture, and also with the sensitivity of the camera sensor.

This relationship is called the exposure triangle, and in a future episode, I will explain the exposure triangle in less than 10 minutes.

All cameras are generally the same.

This principle applies to any kind of camera. Think about an iPhone as the camera body, with a camera lens attached to the body, and an aperture which on my iPhone XS is fixed at F1.8.

How was this for you?

So this is the level of explanation that works for me, which I hope works for you too? We have learned very quickly what a camera is and how it works. Now are there things in here which need much more detailed explanation? Yes, of course.

I’m trying to build myself up here from small beginnings and straightforward explanations by taking (not attacking) things at this level. Like I said I am going to explain the exposure triangle. I’m also going to talk about some of the general camera settings – obviously, there are some that are specific to each individual camera and some that are universal principles of the topic.

A universal rule

Whatever the camera the exposure triangle applies – aperture, shutter and ISO.

Strange terms

There is some very strange and confusing terminology in photography which I will try to get to the bottom of. I think it’s fair to say that if photography was being invented today we wouldn’t have all these things that we have now like the size of the sensor, the terminology and complications of things like the exposure triangle.

I’m rambling now

How long should a podcast episode be? The answer is as long as it needs to be – I won’t stop if I get to 10 minutes and have not finished.

So what’s next on the Photography Explained Podcast?

PE3 – How To Take A Photo? (Not in the podcast episode as I did not know).

Thanks very much for listening, I hope you enjoyed this episode. If you did, please leave a review and rating wherever you get your podcasts from. Also, please subscribe so you don’t miss the next episode and all that good stuff.

I have got one small favour. If you can think of anybody who might enjoy my podcast, please let them know as well. And if there is one thing that you want me to explain on the podcast, let me know.

Okay, thanks for listening. I’ll see you on the next episode – How To Take A Photo?

Cheers from me Rick

OK – that was the podcast episode

Want to know more?

Head over to the Start page on the Photography Explained Podcast website to find out more.

And here is the list of episodes published to date – you can listen to any episode straight from this page which is nice.

Let me know if there is a photography thing that you want me to explain and I will add it to my list. Just head over to the This is my list of things to explain page of this website to see what is on there already.

Let me send you stuff

I send out a weekly email to my subscribers. It is my take on one photography thing, plus what I have been writing and talking about. Just fill in the box and you can get my weekly photographic musings straight to your inbox. Which is nice.

And finally a little bit about me

Finally, yes this paragraph is all about me – check out my Rick McEvoy Photography website to find out more about me and my architectural, construction, real estate and travel photography work. I also write about general photography stuff, all in plain English without the irrelevant detail.

Thank you

Thanks for listening to my podcast (if you did) and reading this blog post (which I assume you have done as you are reading this).

Cheers from me Rick