My aim is to explain things in just enough detail to help us with our photography, and no more. In this episode, let’s get technical.

Photography is an artistic and technical discipline. To be successful in photography, you have to get the technical aspects correct. Composition is vital, but this needs to be complemented by the technical excellence of the image capture, with the correct exposure and tack-sharp images captured every time.

You can listen to the episode here

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

You need to get correctly exposed, correctly focused and tack sharp images every time. As a professional photographer, these are absolutes. Nobody expects you to get these things wrong.

In previous episodes, I’ve spoken a lot about composition. So now it’s time to turn to the technical side of things, one thing at a time, of course, and without the irrelevant detail.

What am I going to be talking about in upcoming episodes?

Here’s a list. I like my lists

• Exposure
• Aperture
• Shutter speed
• ISO
• The exposure triangle (revisited)
• Focus
• Depth of field
• Focal length

There are lots of other things I can talk about, and will talk about but, we (I) have to start somewhere.

Having spent quite a lot of time on some very fundamental parts of photography, I would like to go through what are the next fundamental things

What is exposure?

I will do a full episode on each of these, I’ll just give you a quick flavour of them here.

Exposure is what the camera takes – you have various settings in the camera. When you press the shutter button, you take a photo, the exposure is basically the amount of light that the shutter has let through to the sensor.

Okay, so that’s exposure. Exposure is made up of three components. Now I talked about the exposure triangle in a previous episode. I think I am I covered that far too early for my liking. And I shall revisit it once I’ve explained the three component parts.

Exposure is made up well, it’s not made up of, it’s controlled by three main things.

• Aperture
• Shutter
• ISO

What’s the aperture?

That’s the opening in the camera lens – regardless of what you’re taking a photograph with that is. It could be a DSLR or mirrorless camera, an iPad, iPhone, film camera even. The fundamental is that when you press a button the device takes a photo, and there is something that is controlling the amount of light getting through the sensor.

On a DSLR you can adjust the aperture, but on an iPhone, it’s probably fixed. I think my iPhone XS is F1.8. But I’ll come on to that in another episode.

The next item is shutter speed.

When you’re walking around with a camera in normal day-to-day life (does that make any sense?) the shutter on your camera is closed until you press a button called the shutter release button which opens the shutter. When you press the shutter release button, you open the shutter, and the sensor is exposed to light.

That’s what a shutter does. Not all that complicated, but still a very precise thing.

The time that the shutter is open dictates how much light gets through to the sensor. And that reminds me of going back to aperture. The size of the opening (as in the camera aperture) determines how much light gets through to the camera sensor. I can say I’ll come on to these and explain them all individually, and then I’ll put it all together.

The next item and the third component of the exposure triangle is ISO

What is ISO?

Now, I’ve said this a number of times, I’ll say it again here. If photography was being invented in this tumultuous, I shouldn’t have gone with the big word, I knew as soon as I said it I was going to mess it up.

Let’s try that again.

In 2020, if you’re inventing a thing called photography, you wouldn’t have these things, you certainly wouldn’t have ISO.

What is ISO?

Well, I’ll tell you the bit you need to know here is that the ISO is the sensitivity of the sensor in your camera to light.

So you’ve got an exposure which is made up of the aperture, shutter speed, and ISO.

Aperture, shutter, ISO, these are fundamentals with so many variables, you can’t explain them all together, but you can’t explain them independently. So I’m going to go through each of them in as much detail as I feel will help you.

And then we’ll put it all together with the exposure triangle.

So let’s move on.

Focus

What is focus? You focus on something when you take a photo, and that depends on what you want to do, and what you want to achieve from the photo. But the point here is a technically correct photograph has the subject, whatever it is, and wherever it is, in focus.

Unless you’re doing something artistic.

And that’s a caveat to pretty much anything in photography. There are rules and technical requirements, but you can break them if you have a reason. But you need to know how to do them first, how to achieve them correctly. Depth of field is related to the aperture and also related to the lens, and related to the next point, focal length.

How much of a photo is sharp, or how much of a photo is not sharp, depending on what you’re doing?

Focal length.

Again, this relates to sensor size, which relates to focal length. Like I say none of these things live in isolation in photography. A lot of these things relate to other things.

Post-episode note – a standard focal length (on a full-frame camera) is 50mm. That is similar to what you see through your eyes. Focal lengths larger (longer) than 50mm are telephoto, and focal lengths smaller (wider) than 50mm are wide angle. This is in general, oversimplified terms. I did not say this in the podcast.

It’s complicated.

That’s probably why it gets so complicated because you can’t just talk about aperture on its own without the other things that affect the exposure. You can’t talk about depth of field without talking about focal length, you can’t talk about focal length without mentioning apertures, it all gets a little bit complicated. My job is to uncomplicate it all and make it understandable.

So those are the things I want to talk about first. These are the first technical things that I want to explain to you.

• We’ve done composition.
• We’ve explained what a camera is. And I’m not sure why I’m saying we- it’s just me.
• I have explained how a camera works in very basic terms. That’s better.
• I’ve explained the exposure triangle (I could say too quickly). And now I’m getting to the point where I’m waffling so I am going to shut up.

What’s next in Photography Explained Podcast Episode 21? What does exposure mean in photography?

I’m going to explain exposure. Then I’m going to explain aperture, shutter speed and ISO. I’m really looking forward to breaking these things down so they are single component parts and then putting the whole thing together.

No idea how this is going to go but we’ll give it a go.

Thank You

Thank you for listening. I hope you enjoyed this episode. if you did enjoy it, please leave a nice review and rating wherever you get your podcasts from. And please subscribe so you don’t miss an episode. And if you could do me one small favour and tell one person you know about my podcast, I will be very grateful.

Check out my website Rick McEvoy Photography to find out all about me and my architectural photography and construction photography work. You can also find my blog there with lots of good stuff.

The last thing, if there’s a photographic thing you want me to explain, just head over to my website. Find a way of getting in touch. There are plenty of them.

Check out the list of questions and subjects that I’m going to explain.

Thank you again for listening. I’ve been Rick McEvoy Thank you for giving me 10 minutes of your valuable time, and I will see you on the next episode.

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