The Exposure Triangle

If you want to take control of your photography more then the first step is putting your camera into manual (M) mode. To have the confidence to switch to manual mode you need to be able to understand the importance of exposure values (EV):

Aperture – The size of the opening inside the lens (displayed in ‘f’ stops)

Shutter speed – The length of time the shutter is open (Displayed in /seconds)

ISO – Cameras sensitivity to light

In order to understand how each setting works you have to imagine them as three equal points on a triangle. Changing one setting will have an impact on the other two. Just like if you changed one angle of a triangle the other two angles would also change.

Your setting preferences should change depending on your surroundings. The best analogy I have every heard is one about your eyes because it’s the easiest to understand. Imagine that your eyes are now your camera and with each blink a new photo is taken.

The aperture is determined by how wide your eyes are open. If your eyes are fully open you will be allowing a lot of light in but if you are squinting, like you do when you look at the suns brightness, then less light is hitting your pupils. The confusing thing about aperture is that it seems to work the wrong way round. The smaller the f/stop number, the more light that gets through. So an f/stop number of f/2 would be like having your eye wide open. As your eye begins to squint the f/stop increases in number.

Top Tip - Aperture also affects the depth of field of your image. If your shooting something that’s fair away you want the f/stop to be around f/16+ and if your shooting something macro then bring the f/stop right down and open up that eye of yours!

The shutter speed is determined by the time you take between “blinks”. The longer your eyes are open, no matter how squinted they are, the longer the light is hitting your pupils.

Top Tip - Long exposure images are always breath taking and can look great in your portfolio…and on your wall. A long exposure is taken by leaving the shutter open for a while (at least 1 second). Use this technique to apply a flowing look to water or to show the hustle and bustle of a street. Don’t forget to use a tripod and compensate for your longer shutter speed by reducing ISO and possibly Aperture.

Now imagine at the same time you are wearing glasses that are sensitive to light...So the complete opposite to sunglasses. Imagine you have a little dial on the side that can make the glasses more and more sensitive and allow more light to enter, but the more you turn up the dial the grainer/noisier your sight becomes. This is how ISO works.

Remember that when you change one thing, whether you open your eyes longer or wider or you turn your dial up on your glasses, you have to compensate by changing the other two things so that you can see perfectly (its not too light or too dark).

The best way to learn how each of these settings work is to have the confidence to make mistakes. You will learn so much more if you keep your camera in manual mode and force yourself to improve. Try to put yourself in situations where you have very little light to work with. If you can understand how your camera adapts to low light you will have no problem taking shots on a bright day.

Top Tip - Don’t forget to compensate for any changes made to the triangle!