Photography Basics: Understanding Aperture

It's been a while since I did a photography post, so I thought now was as good a time as any! So far in this series I've covered; Photography terms defined, shooting modes, understanding white balance, and window-light portraiture. Today's photography lesson will be a more in-depth discussion about aperture.

The aperture is the hole through which the light passes through to reach the sensor or film. You can actually control the diameter of this hole on your camera. On old style cameras, there is an aperture ring that goes around the outside of the lens. Moving it around changes the diameter of the aperture.

You most likely will not have an aperture ring on your modern lenses, however, your lens still has the diaphragm inside that allows it to open and close, and you’ll have controls on on your camera that will allow you to control that diaphragm.

The numbers are called f-stops, moving up or down a stop halves or doubles the light let into the camera (the reason that the numbers look strange is down to some tricky math). Even though your camera doesn’t have an aperture ring, you’ll find that you can still adjust the aperture of your camera to these same values (although, depending on your lens, you might only be able to go as low as f4 or 5.6)

One thing that is really important to realize about the f numbers is that the smaller the number is, the larger the aperture is. This can be a bit tricky to grasp at first! If you increase the aperture by one stop (thus doubling the amount of light entering the camera), you’ll need to put the shutter speed down by one stop (and thus halving the amount of light entering the camera).