Understanding Aperture: The Basics - Learn Blog Photography

Understanding Aperture: The Basics

By Amy

May 24

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Understanding Aperture: The Basics

Understanding aperture and how it works can be a little tricky, but keep reading.  Don’t worry I was once just as confused as you.  When I first started learning how to shoot in manual mode I was told by a friend to just play around with the settings and I‘ll figure out what they do, but I was COMPLETELY lost!! This is not how I learn to do things.  

Then, one night a few friends got together and went to the lakefront to shoot the Chicago skyline.  I had never done this before and I was super excited.  With their help, I was able to “play around” with the settings and walked away with a couple shots of the Chicago skyline and the Sears Tower (yes, I know it’s now called the Willis Tower, but to me it will always be the Sears Tower) that I was really happy with.  I was pretty impressed with myself that night.

Here’s one of the shots I took that night.

aperture basics

Sears Tower at the Chicago River

It doesn’t look too bad, right?

Well, this photo was taken with an aperture of f/4.  However, for anyone understands aperture and landscape photography, you would know that this aperture setting is not the best choice for landscape photography.  I realize that this is getting ahead of the game a little, but my point is that by playing around you may do alright, but you may be missing out on a few important things.  Therefore, let’s back up and let me explain aperture a little bit better.

So what is aperture?  Ultimately, aperture refers to the size of the hole within the lens that allows light to enter the camera and reach the sensor.  Obviously, aperture is not the only thing that controls the amount of light reaching the sensor, but that is a topic for next time. Aperture is measured in “f-stops” or by the letter “f” and a number.  An example would be  as f/2.8 or f/4 and so on.  

To me, the most confusing thing to understand regarding aperture is that the larger the opening the smaller the number is.  So an aperture of f/1.4 is called a large aperture or fast aperture because the opening is very large and will allow more light to reach the sensor than a small aperture at  f/22.  An aperture of f/22 will have a very small opening thus allowing only a small amount of light into the camera’s sensor.  Don’t worry, this doesn’t mean that you should never shoot at f/22.  It just means that you have to adjust some of the other camera settings to allow enough light to be captured on the sensor to create a stunning picture.  

Understanding Aperture

Shallow Depth of Field f/1.8

Not only does the aperture change the size of the hole within the lens, it changes the depth of field.  Depth of field refers to how much of the photo is in focus and how much of the photo is blurry.  This is the reason why a landscape photographer would not intentionally set his/her camera setting to f/4.  I can understand that you may be thinking that this is a good idea since it would let in more light than a smaller aperture (higher number) would; however, it will add blurriness into the photo as well.  Depth of field takes into account more than just the aperture number, but since I probably already confused with with a large aperture being a small number, I’ll save this discussion for another day as well.  Just keep in mind that the larger the aperture (smaller number ie f/1.4) will create what’s called a shallow depth of field like the photo you see below.

And, a small aperture (large number ie f/18) will give you more clear depth of field.  This will allow you to be able to keep more of the photo sharp and in focus as you can see below.  

understanding aperture

Full Depth of Field f/18

Don’t worry if you are still a little confused.  It’s not the easiest concept to grasp, but I do recommend getting out and try shooting at a large aperture and small aperture and see the differences.  

There are 2 other MAJOR players in the exposure triangle we haven’t talked about today.  They are ISO and shutter speed.  Make sure you check those out as well in order to fully understand how they work.

Are you understanding aperture a little better now? If so please share this with your friends and post it on Facebook and other social media channels!

If you have any questions leave me a comment below and I’d be happy to answer them!

Are you interested in having a quick reference guide with you while you’re out shooting? Download my FREE Aperture cheat sheet and take it with you!!

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Download the FREE Aperture Cheat Sheet HERE

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About the Author

Amy is the owner extraordinaire at Learn Blog Photography and Amy Paris Photography. She's a single mom to an amazing teenage son. She's passionate about photography and skiing (downhill), the faster the better! Sign up for a FREE 30-min call to light up your photos & biz! bit.ly/2udzBXB