With so many camera modes to choose from, it can be hard to decide which to use and when.
The AV option on your camera menu or dial, is for the aperture priority mode. This means that by selecting AV, you are giving priority to aperture and the f-stop you choose. The camera will adjust the shutter speed and ISO according to your surroundings, on your behalf.
When to use Aperture Priority
AV is a great mode to use if you are weaning yourself off of full auto, and want to have some creative control over your photos. By selecting AV, you can play around with different f-stops, ranging from a wide aperture such as 1.4, up to a narrow aperture such as f16, without having to worry about changing all of the other settings too.
Using different f-stops can create some really interesting effects in your photos, so if you want to create bokeh using a very wide aperture, you can set your f-stop to something like 1.2 or 2.8. As a wide aperture will let in a lot of light, AV mode will tell your camera to compensate for this and adjust the other settings as necessary, leaving you to focus on capturing that bokeh!
Sometimes we can visualise the photo we want to capture, and if you know that you want to only use a certain aperture, Aperture Priority mode will do all of the other work for you. This is especially useful if your light source is constantly changing around you.
When not to use AV mode When on Aperture Priority mode, your camera will always be working to control the shutter speed and ISO to create a well-exposed photo. Sometimes this can cause problems. Say for example you are photographing a moving object and you've selected a narrow aperture of around f16, your camera is going to need to let more light in, so it may slow down your shutter speed and up your ISO. A slower shutter speed will result in a blurry capture of movement.
A good thing to remember when using AV mode is to keep an eye on the settings your camera is selecting for you as you're snapping away.