ISO, Aperture and Shutter Speed. As a photographer or anyone who has a semblance of interest in photography, these three terms are the foundation of everything you must know. I know that may sound a bit dramatic but no matter what kind of camera, being film or digital, each image you capture is a combination of those three special terms: ISO, Aperture and Shutter Speed.
In this article I will break down what ISO, Aperture and Shutter speed are and make sure that it is done in layman’s terms and at a simple level.
So let’s look at this in a simple context. The first thing you need to know is that your camera in it’s simplest form: is a glorified light-capturing device. All that means is that regardless of being film or a digital camera, all your camera is doing is capturing light and converting/chemically compositing that light in the form of an image.
I know MIND BLOW!! Well it’s not that simple technically but when I explain that to my students it makes it relatable. That concept of a camera only being a light capturing device is ECCENTIAL when developing how you see the camera in photography. The camera is simply the way that you capture the light (or image) when taking a photo. ISO, aperture and shutter speed are simply the three variables that determine how much light is captured in the image and how the image will be presented.
The infamous ISO
ISO – What is it? In reality what ISO actually stands for is NOT IMPORTANT but understanding that ISO represents how sensitive your camera/sensor is to light is important. That means that if you increase your camera’s ISO it will make your camera more sensitive to light. This is important in many situations but is commonly use when you have a dark environment where you need to increase your ISO to make the image brighter. Simple concept but hard to learn to trust and know until you invest time in Manual mode learning exactly what happens. An important note is that as you increase the ISO, you also increase grain/noise into the image. I have had many students increase their ISO in class and nothing happens. In many cases that is because if you are in any mode other than Manual Mode, the camera will compensate for the light adjustment with the other variables. Ie. Logically, if you increase your ISO, your image will get brighter BUT if you are in shutter priority mode or program mode etc… that will not happen. This problem happens when you are in any mode other than Manual Mode because the camera has control over the total exposure and will adjust settings without you knowing about it.
https://precisionartblog.wordpress.com/2013/10/16/photography-vocabulary/ (image source)
Aperture or f-stop
Aperture or f-Stop – Is one of the hardest things to get your head around because of the wording and way that it works. Think of Aperture as your eye, more specifically your black pupil in the center of your eye. If you have a small aperture such as f2.8 or f3.5 you are opening up the lens and letting more light in. That is a lot like when you are in a dark room and your pupil is huge because your eye is trying to let more light in. The opposite can be said for a larger aperture number such as f10 or f16, which makes the lens opening smaller, and less light can be captured. That is a lot like when you are outside and in a bright sun. Your pupil will be very small because there is a lot of light and your eye makes your pupil smaller to reduce the light.
Aperture also has a side effect called DOF or depth of field, which is the amount of blurring in your image BUT that is for another article. J
Shutter speed is the third variable and is in many cases the most important one. That is my opinion but doesn’t have to be yours. Now, shutter speed is based on a fraction number ie. 1/125 or 1/2500, which tells you how fast the camera is taking the image. The smaller the fraction (1/2500) the faster your camera takes the image. I will use the analogy of a pie, if you have a shutter speed of 1/15 then you have 15 pieces of that pie compared to a shutter speed of 1/2500 where you have 2500 smaller pieces of that pie. A shutter speed of 1/15 is a slower shutter speed than 1/2500 because if you have a pie with 1/15 (15 bigger pieces) and a pie with 1/2500 (2500 smaller pieces) it will take you less time to eat one of the smaller 1/2500 (2500) pie pieces compared to one of the larger 1/15 (15 pie pieces). I hope that makes a bit of sense and doesn’t make you now want some pie. The important thing to note is that if you want to freeze the action like in sports then you want to have a faster shutter speed ie. 1/2500 or 1/1000. In comparison, if you want to have water look milky smooth then you would have to have a much slower shutter speed of 1/15 of 1 second.
Learning how to use Shutter Speed is essential when learning how to manually control your camera.
As a photographer you can only completely control ISO, Aperture and Shutter speed in manual mode because as I mentioned before, the camera controls the other variables in any more other then Manual Mode. That means you need to get out there and learn how each of the three variables (ISO, Aperture, Shutter Speed) interact with light. I grew in my abilities when I was forced to really understand how the camera captured light and how each of the three variables (ISO, Aperture and shutter speed) interacted with light. Remember that in manual mode: Increasing the ISO, using a smaller Aperture (f2.8) and slowing down your shutter speed all add light to your image. I know crazy, but they all add light in a different way. The same goes for the opposite where if you lower your ISO, use a larger aperture number (f16) and increase your shutter speed you will reduce the amount of light that your camera captures.
Here is a complete chart to help you out.
OK that is enough for now but I will definitely be going into more detail about each variable in future articles. I hope I was able encourage you and inspire you to learn more about your camera and want to take more images.
Thanks for reading. Be inspired and never stop taking photos.