Aperture Tutorial for Beginners in Photography

Getting the Right Exposure

As we mentioned above. the aperture controls the amount of light going further into the camera. Aperture is just one of the items that helps you control the overall exposure of an image. The other two are Shutter Speed and ISO, which we also have tutorials on. 

By using Aperture, Shutter Speed, and your camera’s ISO you are better able to control how your image will turn out.

In simple terms, exposure it about making sure your photograph isn’t too dark (under exposed) or too light (over exposed). 

Any digital camera, from a phone camera to a high end professional DSLR or Mirrorless, uses it’s internal computer to help balance these setting in order to produce the correct exposure. However, with a camera phone or some point and shoot cameras you have very limited control over these setting. If you do have an option to change them it’s often buried in a menu setting.

One of my favorite things when I used my first DSLR or Mirrorless camera was the ability to control the outcome of the image. To me a camera allows you to capture a moment, but a DSLR or Mirrorless camera will let you control what you capture. 

The correct exposure is the right balance of light and dark. Each of these controls allows you to adjust the level of light hitting the sensor, so let’s briefly discuss each.

• Shutter Speed – This is basically how long the shutter is open. So given a certain amount of light, the longer the shutter is open the more light hits the sensor.
• Aperture – This is an opening that allows more or less light to enter the camera. Almost like opening or closing curtains on your window.
• ISO – This term relates back to the days of film and essentially means how sensitive to light the film negative was. In a digital camera it is similar. ISO relates to how light sensitive the sensor settings are.

As with most things in life, a good balance between Shutter Speed, Aperture, and ISO is best. Although there are times where you need to fix or set one of them in order to get the results you want.

For example, if you are trying to freeze motion on someone that is riding a bike then you have to use a fast shutter speed, otherwise you’ll get a blurry picture. Although a fast shutter speed means less time for light to hit the sensor. So if you’re shooting in the early morning when there’s not much light you might get a dark image.

In order to get the correct exposure while still using the faster shutter speed you can adjust the aperture and/or the ISO. It takes some practice and experimentation but understanding the relationship between these three key elements will allow you to control what you capture

What Does the Aperture Do?

So specifically for aperture you can ‘open it up’ (meaning using a larger aperture that will let more light in) to allow for more light. Or you can reduce the aperture to limit how much light is hitting the sensor. Again the goal being the correct exposure (balance of light and dark).

We discuss this more below but here’s a quick reference. 

• Big Aperture = Do you need more light? Simply open up the aperture, meaning make the opening bigger. Let’s say you went from f/8 to f/5.6. This lets in twice as much light as before (Remember the “stop” term? Going from f/8 to f/4 would be 2 stops, meaning you’re letting in 4 times as much light).
• Small Aperture = Is it the middle of the day and there’s too much light? Make the aperture smaller to prevent as much light hitting the sensor and ‘over exposing’ the image. 

In addition to controlling the amount of light, aperture is one of the ways you can control the Depth of Field for your image. Depth of field is essentially how much of the scene is in focus verse how much is blurred. 

Often for landscapes you want to have everything be in focus, both the foreground and the background. While most of the stunning portrait shots you’ll see have the person in focus and the background is blurred.

Using a larger aperture will give you a shallower depth of field, meaning blurred background or foreground. While using a smaller aperture will make more of the scene be in focus. 

As you can see in our Ultimate Aperture Guide Infographic, a large aperture, like f/2.8 will have a ‘shallow depth of field’. Meaning a smaller ‘slice’ of your scene will be in focus. Then as you reduce the size of your aperture that ‘slice’ gets bigger, making more of the scene in focus. We’ve included the detail from our aperture infographic here as a reminder.

Large Aperture – When To Use?

A large aperture is usually anything under f/5.6 (f/4, f/2.8 etc., including all the values in between).

• Large apertures let in more light; great for low light
• Large apertures create a shallow depth of field; great for blurring the background

f/2.8

Any time you want the background to be blurred and pleasing to the eye, simply use a large aperture. Switch to Aperture (Av/A) mode on your camera if you’re not comfortable working in the Manual mode yet, and just experiment with different values and compare the results.

If you’re shooting at night and your images come out too dark, try selecting a bigger aperture and/or a longer shutter speed. You should invest in a prime lens if you want to do low light photography, as their maximum apertures are much bigger than those of zoom lenses. Check out the Canon EF 50mm f/1.8 and Nikon 35mm f/1.8G, both under $200.

Small Aperture – When To Use?

Anything over f/8 is a small aperture, and is mostly used when you want a lot of your photograph to be sharp and in focus (big depth of field). The most common example would be landscape photography, but the same rules apply to everything else as well.

• We use small apertures when we want a lot in focus (main subject, front, back)

The problem with small apertures is that they don’t let in a lot of light, so you might have to raise your ISO speed, use a longer shutter speed and maybe even use a tripod if you’re shooting in bad conditions.

f/8

Depth of field and aperture size are closely related! Making the whole shot appear in focus is also related to the focal length of your lens; the wider it is, the sharper it will look. F/8 could still be used to blur the background in some cases, but it’s the wide 14mm lens that helped a lot in this case!

Conclusion

Point and shoot cameras can be quite hard to control manually, so please read your manual before changing any of the settings.

DSLR cameras on the other hand, are almost identical when it comes to being controlled, it’s what they were made for! Entry level models usually require you to use two buttons/dials in order to change the aperture, while semi-pro cameras have a dedicated button.

• Use big apertures when you want a lot of light, and/or for blurring the background (f/5.6, f/4, f/2.8 and so on)
• Use small apertures when there is a lot of light available and you want sharper results

Pick up your camera, go out and just switch between different values and watch how your photographs change. Perhaps place an object right in front of your camera, and take one shot at f/4 and one at f/16, just to get a feel for it.

Need some additional help?

Do you still have some questions? Do you have a feel for what you want but not sure what you might need to buy? Read through all of our guides but still unsure of what to do? Want to be 100% sure that a lens will be good for low light photography, or that a certain accessory will work with your camera gear?

Visit our partner site, Best Photography Gear, and feel free to just ask us. 

This is all free of course. Your skills, age and location don’t matter, anyone can send us an e-mail and we’ll gladly help.