Camera Specifications Explained

This article gives a high-level overview of common camera specifications including focal length, aperature, depth of field, perspective, and more.

by M. Yates
on May 6, 2018

Photography is a great hobby. It is not just a beautiful way of expressing your creativity, but it can also be a profitable profession. Photography can get complicated, but the best way to make things easier is by tackling one aspect at a time. In this article, we are going to cover some of the common photography specs such as focal length, aperture, depth of field, perspective, and minimum focal distance.

Focal Length

Focal length is a spec that is commonly found in the camera's lens. Hence, every camera lens has a specific focal length. There are people who think that focal length is the distance between the rear of the lens and the film or sensor. This is actually a misconception.

Just like the human eye, a camera's lens has a point of convergence. The distance between the point of convergence and the film or sensor is the actual focal length.

Focal length significantly affects your images by crunching or stretching the "sides" of the image. Keep in mind that focal length is expressed in terms of millimeters.

The standard focal length is around 55 mm. It's often referred to as the "standard" as the lens is close to how the human eye perceives objects. The lower you go down in focal length number, the more the lens will try to fit more elements into the picture. It's the reason why landscape and architectural photography makes use of low focal length so more elements will fit into one picture.

Conversely, the higher the focal number is, the more the background will be "stretched", and your subject will be more zoomed-in. For this reason, cameras with high focal length are often used in action and wildlife photography.

Aperture

In your camera's lens, there's a part that mimics the iris of the human eye. Just like the iris, this part controls the amount of light that hits the film or sensor. This part is also known as the aperture.

Aperture is expressed in terms of F-number (e.g. F/2, F/4). For many photographers, the widest aperture size is the biggest concern when it comes to the aperture spec. This is because the wider the opening, the more light can pass through. This can have a big impact when taking shots.

For one, a wide aperture means that the photographer can use higher shutter speeds. This is something that is sought after especially if one is shooting at low-light conditions. Another reason why maximum aperture opening is a concern is because how it relates to depth of field.

Depth of Field

Keep in mind that a camera is only able to sharply focus at one point. Hence, when focusing too much on an object, it's inevitable that there will be areas of the image that will be blurred. The zone in which the resulting image is not blurred and sharply focused is known as the depth of field.

Camera lenses often come with a "Depth of Field" specification, and it's often expressed in terms of millimeters. This number is often used to calculate the optimum depth of field range. The depth of field specification will also give you a hint when it comes to the lens's ability to maintain a sharp focus on an object as it moves closer or further.

While you are always welcome to use the depth of field spec as a way of calculating the optimum depth of field range, the method is not very popular. One reason for this is because the math is a bit complicated, and it can take out the enjoyment of taking pictures.

It's best if you simply learn how to manipulate distance and the aperture of the camera as a way of getting the desired depth of field range. This method is not just a lot more enjoyable, but it's also a lot less complicated.

Perspective

The perspective in a lens spec is a term used to describe that visual effect in which the objects appear smaller and smaller as the distance from the viewer becomes farther and farther. In photography, perspective and focal length are closely related. This is because one can control the perspective by changing the focal length. Perspective and/or focal length can then be described in terms of wide or long.

Wide angle lenses distort perspective by making the objects that are nearer to appear larger, while making the objects at a distance smaller. On the other hand, long or telephoto lenses have small perspective angles. As a result, the objects will be distorted as if they appear they have similar sizes even though the distances between the objects are greater. Keep this in mind when if you use your camera to record YouTube videos, because perspective strongly influences an audiences view of the video.

Minimum Focal Distance

The lens of a camera essentially works like a binocular. Most binoculars come with at least two lenses. These lenses can be moved closer and further. It's up to you on how you dial the buttons so you will get the right mix of magnification and focus. The lens of your camera also works similarly.

Just like a binocular, the lenses in a camera can be moved to provide you with your desired effect. Nevertheless, there's a limit in which the lens can move. Hence, there's also a limit in sharpness and magnification. In most cases, the limitation circles around the minimum focal distance.

Have you tried using a binocular and use it on an object that's only an arm-length away? In most cases, no matter how much you dial the buttons, you can't seem to get a sharp picture. This is because there's a minimum distance in which the binocular and camera lens can focus sharply, and this is because the lenses can only move to a certain point. This distance is known as the minimum focal distance.

The minimum focal distance is often expressed in meters or in feet and it can usually be found at the side of the lens's body. Minimum focal distance is a significant spec to check if you are planning to do a lot of close-up shots. This is because if you are too close to the subject (to the point that you are closer than the focal minimum focal distance), it will be tough to take a sharp image.

So, that's it for now. There are plenty of other important specs that you should be aware of. But, take one step at a time. Knowing the specs we mentioned above is a good way to start.