What’s an ƒ-Stop and How Does Aperture Control Depth of Field?

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Photo by Markus Spiske

Photography is extremely seductive for a lot of people around the world, it can be practiced at a professional level or as a very strong hobby. One of the biggest interests of all people who approach photography is to learn how to use a camera in manual mode. This feature empowers anyone to create extremely creative images beyond the “perfect” modes the camera figures out when shooting in Auto or Program. In photography, everything is about capturing light and today we are going to talk about one of the most complex features there is in exposure, Aperture.

Why Aperture is So Difficult to Understand?

Don’t feel bad if you are struggling with aperture, it is the most difficult feature to master when it comes to exposure, and we’ll explain why. First of all, the strange numbers. Everything in exposure controls stops of light, and aperture controls how many light will pass through your lens via aperture values.

These are Aperture Values for 1 stop of light:

ƒ/1.0 ƒ/1.4 ƒ/1.8 ƒ/2.0 ƒ/2.8 ƒ/4.0 ƒ/5.6 ƒ/8.0 ƒ/11 ƒ/16 ƒ/22

These are Aperture Values for 1/3 stop of light:

ƒ/1.1 ƒ/1.6 ƒ/2.2 ƒ/3.2 ƒ/4.5 ƒ/6.3 ƒ/9.0 ƒ/13 ƒ/18

These are Aperture Values for 2/3 stop of light:

ƒ/1.2 ƒ/1.8 ƒ/2.5 ƒ/3.5 ƒ/5.0 ƒ/7.1 ƒ/10 ƒ/14 ƒ/20

The trick here is to see these numbers as fractions, if you manage to keep this in mind every time you move aperture values, you can be sure that you’ll master them in no time.

Imagine that the letter “f” is a number 1, and the numbers below are simple denominators, you’ll understand that the larger the denominator, the smaller the aperture hole on your lens.

Keep This in Mind:

  • The shorter the hole, the shorter the amount of light.
  • The larger the hole, the larger amount of light.

If you keep the aperture value low, you will have brighter images. Whenever you get images that are looking to bright for you, you could move your aperture value a bit to reduce the amount of light passing through your lens.

If you are getting images that look too dark for your taste, you should open your aperture value in order to increase the amount of light and you’ll avoid dark images. The trick here is to find the sweet spot for every lighting condition that you deal with.

What About Depth of Field?

Aperture doesn’t only control the amount of light but also how light and distance behaves inside our camera. Large apertures create shallow depth of field (DoF), creating beautiful blurred backgrounds in our images. That’s why portrait photographers love to use lenses that allow them fast apertures like ƒ/1.4 or ƒ/1.8. If you close the aperture down, you’ll achieve deep levels of DoF, extremely useful for landscape photography.

If you don’t understand this so clearly, let me explain it in the most easy way there is, by using your own fingers and eyes. Think of your eyelids as the (controllable) aperture of your eyes, if you put for finger close to your eyes and you try to focus it, you’ll instinctively open your eyelids, and your finger will appear in focus, but the background will blur out. If you focus something in the distance, you’ll close your eyelids, but everything will remain in sharp focus.

Pro tip: Be careful with fast apertures since they tend to have a very small and even critical area of focus. This could be extremely annoying if you don’t have a skilled hand an eye.

Keep in mind that we have shared this text for you in order to make aperture understandable alone. That’s why we have avoided complexion our minds with shutter speeds and ISO values. Aperture is abstract, but we are aiming here to make it extremely easy for you to understand it.

Photography is all about practice and more practice. It takes different amounts of time to master it, and every person has a different learning rhythm. The best thing that you can do in order to become a better photographer is to take your camera wherever you go, and start thinking in terms of light. Whatever you do in photography, do it with passion, and you will have the time of your life!

Originally Published at Light Stalking

Scholar & Writer on Photography | PhD Student | Photographic Guidance https://federicoalegria.com/guidance

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