For those of you still struggling to get to grips with aperture, we bring to you our handy F-Stop Chart Infographic / Cheat Sheet.
Many of you will have grasped the basics of aperture from our Exposure Triangle explanation, but getting your head around f-stops can be a real sticking point for many beginner photographers.
Sometimes, nothing can compete visual learning, so we’ve put together this easy-to-understand infographic illustrating how changing the aperture can effect our final image.
Here it is! Refer back to our F-Stop Chart as we explain a bit more about apertures below, save it for future reference, print it out. Basically, do whatever you want with it!
Aperture / F-Stop Chart
Aperture and F-Stops
You’ll probably have heard this corner of the Exposure Triangle referred to as a number of things, such as aperture, f-stop, f-numbers.
Not to worry! We’ll clear up any lingering confusion in this section.
What is Aperture?
The aperture is, quite simply, the opening inside your lens that allows light from the outside world through to your sensor.
This term refers to the actual physical component in your lens. The bigger the aperture is able to open, the more light that your sensor can collect.
As you can see on the left hand side of the F-Stop Chart above, wider aperture = brighter image.
What About F-Stops?
While the term aperture refers to the component in your lens, f-stops refer to our way of measuring the size of the aperture opening.
One of the most confusing aspects for beginner photographers to wrap their heads around is that a lower f-stop number = a bigger aperture.
Now, there’s a lot of math surrounding this that you don’t really need to know, but the takeaway lesson is that f-stops aren’t referring to whole numbers, but to fractions.
The “f” actually stands for focal length, so the physical diameter of the aperture is measured like this:
focal length / f-stop = aperture diameter in millimeters.
For example, if you’re using that old favorite the 50mm prime at an f-stop of f/1.8 the diameter of your aperture would be:
50 / 1.8 = 27.78mm
Math lesson over! All you really need to remember is that a smaller f-stop equals a wider aperture.
So, What Are These F-Stops?
In photography, a stop is a unit of measurement to quantify the overall exposure of an image.
So, when we change our aperture by a full stop, we either halve or double the amount of light reaching the sensor (providing other settings remain the same.)
These full stops are below, although note that most of the time you can change your aperture in increments of 1/3 stops.
Commonly Used F-Stops
f/1.0 > f/1.4 > f/2 > f/4 > f/5.6 > f/8 > f/11 > f/16 > f/22 > f/32
How Does Aperture Affect My Photography?
Now we get down to the nitty gritty of exactly what changing aperture can do to our images.
There are two main things to consider when choosing an f-stop number: Exposure and Depth of Field.
Shutter Speed and ISO
Aperture, shutter speed, and ISO make up the three corners of the Exposure Triangle.
That means that when one of these settings is changed, one or both of the others must also be changed to maintain the same level of exposure.
It might sound complicated, but it’s actually pretty simple. If you stop down your aperture by one stop (eg, changing your f-stop from f/8 to f/11), you must then either double your ISO value (eg ISO-100 to ISO-200) or double your shutter speed (eg 1/30 second to 1/15 second) in order to maintain the same exposure.
This is why fast lenses, which are lenses with a wide maximum aperture, are so expensive and sought after. The wide maximum aperture means a faster potential shutter speed, which allows you to handhold the camera even in low light situations.
Depth of Field
I’ll spare you any more boring science, but as you can see from our F-Stop Chart, a wider aperture (smaller F-Stop number, remember?) results in a shallower depth of field.
A shallower depth of what?
Depth of field is basically the amount of an image that is in focus. A number of factors effect the overall depth of field, such as focal length, distance to subject, subject to background distance etc.
However, one of the main factors the aperture. As the Aperture Chart shows, a wide aperture results in a shallow depth of field (DoF), while stopping the aperture down increases the DoF.
What level of depth of field you’re actually aiming for depends on the individual image and your photographic preferences, but just remember this: If you want that creamy out-of-focus background use a small f-stop, and if you want as much as possible in focus use a large f-stop.
For instance, many wedding and portrait photographers love using a shallow DoF because of the gorgeous separation it can give between the subject and the rest of the world. Meanwhile, most landscape images (although definitely not all) benefit from a large DoF.
There we go! Hopefully our explanation, along with the F-Stop Chart, has cleared up any lingering confusion surrounding aperture and given you a better idea of how you can use it creatively.
Good luck and have fun!
Alex is the owner and lead writer for Click and Learn Photography. An avid landscape, equine, and pet photographer living and working in the beautiful Lake District, UK, Alex has had his work featured in a number of high profile publications, including the Take a View Landscape Photographer of the Year, Outdoor Photographer of the Year, and Amateur Photographer Magazine.