Love your camera / understanding aperture?

Some of you may have seen that I launched my LOVE YOUR CAMERA workshop recently. I’m so excited about this. It’s a workshop that will give straightforward advice and guidance, inspiration and direction to those who want to learn more about photography and get to grips with their camera.

I thought it would be great to build on the teaching by doing a series of blog posts that cover a few of the aspects we will be covering in the workshop. Things you will be learning and getting to put into practice.

UNDERSTANDING APERTURE

Aperture is one of the three parts that make up the exposure triangle. The other two being shutter speed and ISO. Aperture plays a big part in creating dimension in a photograph. It can bring the background into sharp focus or make it blurred.

What is aperture?

In it’s simplest term the aperture is the hole through which the light travels into the camera body and onto the sensor (or film). The larger the hole the more light comes in, the smaller the hole the less light comes in. Adjusting the aperture adjusts how much light is let in.

Choosing the aperture size.

The choice of aperture size has a big effect on an image. Not only does it change the amount of light entering the camera but it also has an effect on how much of the background is in focus. This is called Depth of Field and I’ll go into more detail on this in the next point.

In photography the aperture (or hole) is expressed in terms of f-stops. These are the way to describe the size of the aperture and how open or closed it is. Remember, open means a lot of light coming in, closed means less light coming in. Conversely a smaller f-stop number means a larger aperture and a larger f-stop number means a smaller aperture. It can be confusing, but something you just need to learn!

For example: f/2 is larger than f/4, which are both much larger than f11.

aperture illustration

What is depth of field?

Depth of field is directly affected by the aperture you use, but what is depth of field? It is the area of the image that appears sharp and in focus. When you use a small aperture (a larger f-number) more of the image will be sharp, when you use a large aperture (a smaller f-number) less of the image will be sharp.

The top image was shot at f/1.8. The bottom image was shot at f/5.6. You can see that the background is clearer in the bottom shot where the aperture is smaller.

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Here is another example of using a larger aperture. The girl in the photo is clearly in focus but the background is blurred and not in focus. This shot was taken at an aperture of f/2.8.

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What the numbers mean on a lens.

When you look at a lens you will see a number or a range of numbers that indicates the largest aperture that the lens will achieve. The smallest aperture a lens will go to is generally not noted as it isn’t as important. Most lenses will go to f/16, which is more than adequate for the majority of photography.

There are two types of lenses, zoom and prime (or fixed) lenses. Zoom lenses give you the flexibility to zoom in and out without the need to move closer or further away from the subject. Fixed or prime lenses only have one focal length. Due to the complexity of the optical design many consumer zoom lenses will have variable apertures.

On zoom lenses you might see a range of numbers, for example, f/3.5-f5.6 will be noted on the lens. This means the aperture is variable and changes as you zoom. To achieve the widest aperture you have to be at the widest zoom setting. As you zoom in the maximum aperture will change.

The more expensive, professional zoom lenses, on the other hand, typically have fixed apertures. For example, the Nikon 24-70mm lens has the same maximum aperture of f/2.8 at all focal lengths between 24mm and 70mm.

On a prime or fixed lens you will see just one number, for example, 1:1.8, in this case this means that the lens has a maximum aperture of f/1.8.

This ‘maximum’ aperture indicates the speed of the lens. What does this mean? Lens speed is the term that is used to explain how much light a lens will let in. For example, a lens that can go to f/1.4 or f/1.8 means it has a very large aperture, which means it will let much more light in than a lens that goes to f/4 so is a ‘faster’ lens.

Why do these numbers matter?

The number on the lens let you know how fast the lens is. Faster lenses work better in lower light situations, because they let in more light. It’s also worth remembering that the larger the aperture the better the ability to isolate the subject you are focusing on from the background.

If you have any questions do leave a comment or get in touch on fiona@fionakellyphotography.com

If you think you would like to join me at the LOVE YOUR CAMERA workshop to learn more about using your camera, then check out the details here.

Thanks for popping by

Fiona x