What is a Camera Viewfinder? Definition and Examples.

Published: June 25, 2020 | Last Updated: December 12, 2024

Whether your camera has an OVF or EVF, you won’t be able to see the image you are composing without a viewfinder, making viewfinders a vital part of any camera.

We’ll review more about the two main types of viewfinders, how they work in modern DSLR and mirrorless cameras, and why they are important to videography beyond the obvious—seeing your image.

But first, let’s take a quick historical look at the origins of viewfinders.

The origin of the viewfinder

The original viewfinder design came into fruition thanks largely to the telescope’s creation—specifically, the Galilean telescope. This is why the first viewfinders can be referred to as Galilean viewfinders, as they follow the same design as Galileo’s telescope.

A Galilean viewfinder is a simple-to-create two-piece design that allows a viewer to see a subject by placing their eye at the back of the scope to see the scene through the viewfinder. It uses a front plano-concave lens and a rear or dual convex lens. These two pieces create an afocal system, which creates an infinite focal length.

In the case of an actual telescope, that infinite focal length allows you to focus on stars that are very far away, and in the case of a camera lens, it allows the lens to zoom in on a subject. However, the original form of the viewfinder was a direct viewfinder, which is different from the viewfinders of today.

Direct viewfinders and rangefinders

While today’s viewfinders show you the image directly from the lens via mirrors or a digital recreation via a sensor, a direct viewfinder points the same way as the lens. Still, it approximates what the lens taking the photo is seeing.

Galilean viewfinders are the main type of viewfinder you’ll find in vintage cameras, but not every camera uses a Galilean viewfinder. That’s because when creating the parallel image in the viewfinder, certain errors of light manipulation, like parallax error, made it hard to get the image exactly right.

So once an alternative was created that allowed you to see what the lens was seeing, there was no real point in approximating.

Some cameras use viewfinders known as rangefinders. These created a split-image system by taking two views from two separate windows on opposite sides and combining them to create a single image for the viewer looking in the middle.

Cameras using this type of viewfinder, called rangefinder cameras, are still used today by modern photographers and are useful for providing a greater field of vision and sense of scope when photographing without the need or bulk created by a zoom lens.

Enter SLRs and DSLRs

As a photographer or videographer, you’re familiar with the term DSLR when describing cameras, but just in case you need a refresher on what DSLR stands for, it stands for digital single-lens reflex.

Before the advent of digital cameras, there were SLR or single-lens reflex cameras. Single-lens reflex refers to the camera only having one viewfinder.

Instead of a direct viewfinder that tries to imitate what the lens is seeing, the original SLR cameras used a mirror to reflect the actual image the lens is seeing upwards so a photographer could see it themselves when looking down at the camera held at waist level. 

This mirror was mechanized so it could be moved out of the way when it came time to take the photo, and newer SLR cameras added a prism that reflected the light straight forward so the photographer could use a viewfinder at eye level.

DSLR cameras imitate this ability to see exactly what the lens sees with a live preview option, which is why they have become so popular.

Optical versus electronic viewfinders

For most modern cameras, the viewfinder options are optical viewfinders (OVFs) or electronic viewfinders (EVFs). As we mentioned above, older DSLR cameras use optical viewfinders exclusively, while some newer DSLRs and mirrorless cameras use electronic viewfinders.

Optical viewfinders are any of the viewfinders we just listed, while an electronic viewfinder recreates the image with a digital sensor and plays it through an LCD screen.

Many videographers and photographers prefer optical viewfinders because they show the scene they are photographing as it really is, while even the best EVF cameras still reproduce the image.

However, using an electronic viewfinder comes with some benefits – for example, the image you see in an EVF camera will change when you adjust the exposure so you can see how what you are changing will affect the final image.

OVF cameras are limited to only what the lens is looking at, so any settings you change won’t change the look of the image in the viewfinder – only the final image.

Plus, because EVFs are essentially mini-LCD screens, you can playback footage from the viewfinder directly instead of using a pop-out LCD screen that could be hard to see during daylight shooting situations.

LED display differences between OVF and EVF

Both viewfinders include overlay displays that provide information for the photographer or videographer to use when composing their shot.

OVF cameras will usually provide the aperture and ISO settings, as well as a box that defines the outer frame of the image to determine how much information the photographer sees is being picked up for the final shot.

EVFs, meanwhile, have additional menus that can be accessed directly through the viewfinder. These menus include displays that help adjust the image the EVF is producing, such as the brightness and sharpness of the image.

There are also “quick menus” the photographer or videographer can access from the viewfinder to adjust all the other options without having to pop out an LCD screen and scroll through like on a DSLR.

But wait – don’t digital cameras have both OVFs and EVFs?

Yes, that’s technically correct. The LCD screens on a DSLR camera are technically electronic viewfinders, and many cinema cameras use an EVF at eye level and a higher resolution monitor you can attach to the side of the camera as an EVF.

Some cameras even use a hybrid viewfinder. In these instances, a mirrored prism reflects the image to the OVF so the photographer or videographer can see the frame and data from the overlay. Alternatively, a mechanism that turns the prism into a mirror can turn off the EVF completely.

”Block” cameras, such as those from RED, Z cam, and Kinefinity, don’t come with a viewfinder. They’re modular cameras, meaning you build the camera from the basic ”brain”—or block—to suit your needs. So you can add a viewfinder if you need it—or you might skip it and use an external monitor instead.

Mirrorless cameras, like the Nikon Z-series, Sony A7 series, or Panasonic GH5, are EVF only and don’t have an optical viewfinder option.

Why viewfinders matter – besides the obvious

Let’s get this out of the way – viewfinders are great because they help you see the image you are shooting! But why else are they important? It depends on what type of viewfinder you are talking about.

OVFs are great because they allow you to see what the camera sees. They show you the whole frame, even beyond the frame, and reveal to the world how it really looks.

Even though you can’t see how the shot will look in its final form with the current settings, if you know your camera and how it looks, you can use the overlay to adjust your aperture and ISO right there in the viewfinder—an endlessly helpful tool, especially if you are shooting an active scene, be it a sports game, wildlife in nature, or an adventurous moment.

EVFs, meanwhile, provide so much more value with additional menus you can access right in the viewfinder. This makes it easier to adjust what you are doing and see the results of those adjustments and how they affect the final frame.

Summing Up

Viewfinders are most important because they help the camera feel like an extension of you and your vision.

By putting your eye to the viewfinder, it’s as if the camera is your eye now.

Thinking of the camera as an extension of you makes your actions more fluid, keeps you more focused and glued to your work, and increases your chances of getting the right timing to capture those perfect shots.

I believe this mentality is the difference between keeping one’s work at arm’s length and making it personal—figuratively and literally.

Up Next: External Camera Monitors – What to Look For