What is a prime lens?
To properly explain what a prime lens is, it is worth knowing the difference between a zoom lens and a prime lens. The difference is not very difficult: a zoom lens has a variable focal length, whereas a prime lens has a fixed focal length. With a prime lens, you can’t zoom in. You, the photographer, will have to move to create the desired distance between you and your subject. The advantage, however, is that prime lenses are more light-sensitive. This is because the aperture of a zoom lens is generally smaller. With a prime lens, you will find that your photos are sharper and have more detail. That's because there are fewer moving parts in a prime lens, and the light only has to pass through one lens instead of multiple lenses. You will also notice this in the weight, prime lenses are generally lighter than zoom lenses. With a prime lens, you don't have to consider what focal length you want, you only have to focus on your aperture and the focusing distance. So, as mentioned earlier, you yourself will have to move if you want to get closer. The beauty of that is that you achieve beautiful and creative compositions.
Read all about composition in our article "What is composition?".
When do I buy a prime lens?
Prime lenses are available in different focal lengths. Therefore, it depends on what you want to photograph. For portrait and product photography, a 50 to 100 mm prime lens is perfect and definitely a must. You could take a 135 mm prime lens with you for sports photography or travelling, while a 35 mm will also work perfectly well for filming. Also, don't forget the light sensitivity of the lenses. For all prime lenses, the large aperture they usually have means they capture a lot of light. So you don't need to crank up your ISO in dark environments.
Pros and cons at a glance