Function Basics: The Exposure Triangle

It's time to bring it all together.

I've previously talked about aperture, ISO and shutter speed in seperate posts. However, these three features are far from seperate, in fact they are all connected and dependent one on another. Knowing how to use them individually is the first step to being able to take great photos. The next is being able to use all these three functions so that they compliment each other.

Together they are known as the 'Exposure Triangle', because in aligning all these features correctly you are ensuring the image is not underexposed or overexposed.

So how do they all work together?

Lets say you're out shooting during the day, meaning there's lots of light around. Say in this scenario you're using a big aperture, meaning not much light is being let in, what should you do here? Well to fix this the sensor in your camera just needs more time to collect light. To enable it to do this the shutter needs to stay open for longer, so you need to choose a longer or slower shutter speed.

What about if you're shooting with a smaller aperture in this type of environment? Obviously in this case you'll be allowing a lot of light in, which is the opposite of the situation above. So you need to respond in the opposite way as well by setting a shorter or faster shutter speed, to help ensure you don't overexpose your image.
So if you were to increase your shutter speed from 1/125th of a second to 1/250th of a second, you're basically cutting the amount of light your letting in, in half. To then compensate for this you have two possible options, and which you choose may depend on what type of situation you're shooting. You could increase your aperture by one stop or choose a faster ISO (remember though the higher your ISO, the more grain or noise you start to introduce into your photo).

If you're just starting out a great way to practice is in Aperture Priority Mode. In this mode you only have to figure out what aperture is correct for your situation, and the camera does the rest of the work. It can also be good to have a go shooting in the other available modes (such as shutter priority) so you can really start to practice and learn how each element of the triangle affects another.

What's your opinion?

  1. Thanks for posting this series! I've been really keen to get back into photography lately. I'd much rather use my own photos than some royalty free ones on my own blog! These posts have been super helpful and I may even whip out the DSLR today. Maybe tomorrow haha..

    x Rana from The Picasso Playbook

  2. Aww I'm glad to hear it's been helpful :) Yeah I think using your photos makes a blog much more personal, helps you tailor it more to what style you like and you just overall get more satisfaction out of a post knowing you've made every element of it :)

    You should definitely get that camera out girl!, haha.


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