Photography for dummies. Exposure triangle explained!

Published on 9 May 2020 at 02:16

In previous posts, Photography101, 102,103, we saw about the three pillars of photography and how they affect our photos.

We saw how to adjust their values in order to achieve the photo that we have invisioned in our minds.

So now lets put it all together so we can work with them at any situation depending on what we want to achieve!

Let's start with exposure. Above you can see a typical indication of the lightmeter in most cameras nowadays.

The camera will tell you, based on your settings, how the picture is going to be.

  • If it is on the plus side it is going to be bright. 
  • If it is on the minus side it is going to be dark.

As you will see the distance between 0 and +1/-1 is 3 grades. This ''distance'' or movement is called one stop (1 stop).  

Each one of these grades is called a click.

So one stop = 3 clicks.

The photometer of the camera will move, by one click each time you will make any adjustement that is gonna affect the light in your photo. 

So for example if you change your shutter speed from 1/30 to 1/40, this is going to be one click in the photometer.

This is a ood way to keep track of your exposure.

Now this a typical camera screen, I believe you are all familliar with. 

You can see the shutter speed, the aperture and the ISO values. What all these 3 have in common, is that they all control the amount of light in your photo.

Your goal is to adjust these settings and aim for the photometer to be in the middle, which indicates that your exposure is on point. 

P.S: That's not always the case, we are going to talk about the mettering modes on another chapter.

Experience TIP: I found that an underexposed picture, by only ONE CLICK, gives a higher contrast. Try it out!

Ok, now what's the idea behind all these.

So you have your photometer, telling you if you exposed your subject properly.

And you have your subject, which is either moving or being stable or you want to make it appear in a certain way in your photo.

As we talked in previous posts, each ellement, controls also a different aspect.

  • Shutter speed controls the movement
  • Aperture controls the depth of field
  • ISO is responsible for the noise

Depending on your creative style and how you want to make the subject look you need to adjust your settings to make it happen, considering also your photometer to make sure that your exposure is also on point.

It is not as dificult as it sounds. Besides that is the whole magic. Having complete control of how the picture will look!


Lets check some examples to understand better what im talking about.

So i am looking at this picture. My way of thinking is that i keep the ISO at the minimum to ensure that there is not going to be any noise.

Then i think of how i want my picture to look.

In this spesific case, i wanted the sun to apear like a star with the rays all over the place. To achieve that i needed to put my aperture value at f16.

This automatically restricted my light so my photometer showed that the picture is underexposed.

At the moment my shutter speed was around 1/400. So i adjusted that first to get as low as i could and get as much light as i could too. I setted then the shutter speed at 1/80 and i saw that the photometer showed me -1 click from zero.

Based on the fact that my shutter speed was going to be sufficient enough to avoid camera shake ( i was shooting at 15mm) and my ISO was in the minimum and the sunject looked how i wanted, i pressed the shutter button!

And voila! I made a photo!

So that's the proccess of making a photo! Well at least the technical aspect of it, regarding the settings. I know it sounds like a lot, but trust me after a while and after some practice all these things and calculations will come naturaly without even looking at your camera!

         Lets see one more example, shall we?!

So i found myself to Geneva lake this February. The place was amazing, ut being winter meant that the weather was gloomy and cloudy which means less light.

At the time I was using my 70-200 f4 lens.

That means 2 things

  • first, my shutter speed cant go under 1/200 so i can ensure no camera shake
  • and my aperture cant go lower than f4

So already i start with shutter speed of 1/200 and i set the aperture at f6.3, because i wanted to make sure that the depth of field will be sufficient enough, to give me a crispy photo.

Then i looked at my photometer and saw that is was at -2 stops from 0.

So the only thing i had left to change was the ISO. So i setted the ISO at 400. That made the photometer show exactly 0.

So my subject was as i wanted, clear and focused through the whole frame, there was no camera shake chance cause my shutter speed was high enough and the ISO was withing low limits. 

I pressed the button and made the photo! Voila!

You can use this picture as a small cheat sheet to help you have a quick look when in doubt!

Do you get the picture?! That is pretty much it! You got this?! Then you got the basics to start shooting in manual mode and start exploring!


Lets recap!

  • Acknoledge your limitations (lens focal length, your ISO, your availale light, your maximum aperture and so on)
  • Decide how you want your subject to apear in your photo ( blurry background, dark, light, crispy, show movement, freeze movement etc.)
  • Adjust your setting according to that
  • Check your photometer
  • Adjust your settings, if the photometer indiciation is not good (underexposed/overexposed), so it will be at zero
  • Press the button and make the photo!

Now turn your camera at manual and start experimenting!

Happy shooting!

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