Tag Archives: how to take pictures

So You Wanna Take Better Pictures Part 2: What is aperture?

5 Jul

For the first How To in this series see So You Wanna Take Better Pictures.

What is aperture?

Aperture: a circular opening that limits the amount of light that can enter and expose the film/sensor.

The aperture size determines the amount of light that is allowed to reach the sensor. We know aperture in F-stops. The smaller the F-stop number then the larger the lens opening (aperture). So an aperture f/2.8 allows more light to reach the sensor than f/5.6 and f/5.6 allows more light than f/22. This can be a little confusing as the bigger the number equals less the light.

Quiz time!

Say that you have a lens and the aperture range is f/1.4 to f/16.

What is the maximum aperture size?
What is the minimum aperture size?

If you answered that f/1.4 is the maximum size and f/16 is the minimum then you score a gazillion gold stars! Why you ask? Because f/1.4 allows the most light (large aperture) and f/16 allows less light (small aperture).

You want to take a picture of Timmy so that he is the only thing in focus and the background is blurred. You can accomplish this with a large aperture. The smaller the number then the larger the aperture size. So an aperture of f/2 will give you that blurry background while Timmy is in focus.

Jane and Rover are playing on a hill and you want all of the picture to be in focus. What aperture size will produce this outcome? A small aperture you say? Another gold star! You select f/16 and grab a clear shot of the bushes, Jane, Rover and the beautiful trees behind them.

Below is an example of an f/3.5 aperture and an f/22 aperture as well as the same picture taken with each. Do you see the differences?





Next we’ll discuss Depth of Field which is directly related to the aperture size.

Got it? Let’s try it and let me know if you have questions or need a little assistance!

traci-marie Rogers
traci-marie Photography

Try It Exercise:
1) Set your camera to Aperture Priority Mode. You will be able to select the aperture to use and the camera will select the shutter speed
2) Find a stationary well lit object that you want to photograph (something near a window or under shade)
3) Set your aperture to f/2 (large aperture) and snap a picture (if you do not have this aperture then select f/3.5)
4) Set your aperture to f/8 (medium aperture) and snap the same picture
5) Set your aperture to f/22 (small aperture) and snap the same picture
6) Look through each image to view the difference between each. Notice what is in focus between each.

What did you find?

Glossary for this lesson:

Aperture: an opening, such as a hole or slit; in a camera, a circular opening that limits the amount of light that can enter and expose the film.

Depth of Field: the distance between the nearest and farthest objects in a scene that appear acceptably sharp in an image.

Shutter Speed: the rate at which the aperture of a camera opens and closes to let in light and expose the film.