Even though Canon introduced its first EOS mirrorless cameras a decade ago, there are many photographers who continue to use digital SLRs for much or all of their work. This can range from casual snapshooters, working with entry-level EOS Rebel (or similar) models, to professionals who shoot weddings and events with more advanced DSLRs, such as an EOS 5D-series model. There’s no question that a digital SLR takes the same pictures today that it did when it was brand-new, and that is sufficient for some users. But in this series, we’ll try to show some of the reasons photographers may want to take another look at mirrorless cameras.
The eye-level, electronic viewfinder (EVF) is a marked improvement in some ways over the optical viewfinders used in SLR cameras. In this article, we’ll explore some of the reasons that the viewfinder can be a compelling reason to consider stepping up to mirrorless, for current digital SLR shooters.

In this first installment, we’ll look at the first thing most users see in their cameras — the viewfinder. The gains available with the sophisticated Electronic Viewfinders (EVFs) in mirrorless cameras really should be considered, even by hardened DSLR enthusiasts.
Electronic Viewfinder Fundamentals
Simply stated, you can think of the EVF in a mirrorless camera as analogous to your LCD screen’s Live View appearing in the eye-level viewfinder. You still see subjects go in and out of focus, and you get virtually a 100% view of the scene as it’ll appear on your finished digital image — unlike many affordable DSLRs, the EVF rarely, if ever, crops the edges of what you see in the viewfinder.
It is absolutely true that an EVF uses battery power, and in most mirrorless cameras, the fact that its (usually) higher resolution than the rear LCD screen means it’ll usually draw more battery power than Live View on the LCD screen. But — in exchange for that drawback — the EVF provides a host of terrific benefits, some or all of which can enhance their shooting possibilities in many situations.
Low-light Viewing
As light levels in a scene drop, the EVF’s benefits in low-light viewing really become apparent. Composing, focusing and assessing exposure are all significant EVF advantages, relative to traditional optical viewfinders.

There’s no question that the Electronic Viewfinder will provide great viewing potential in dimly lit situations, even bordering on near-total darkness, in many situations. With the optical viewfinder in a DSLR, the entire view just gets darker and darker as the light levels fade. With the EVF, your view can progressively be lightened as actual lighting in the scene drops, making it far easier to view and compose your images and video. This is entirely on top of the ability with most mirrorless EVFs to brighten or darken the overall view, to match a user’s preferences.
Record Video Through the Viewfinder, as Well as on the LCD Screen
While we often think of video as something recorded using the rear LCD screen, mirrorless cameras with Electronic Viewfinders can likewise record video through the eye-level finder. Two immediate advantages, if you do:
- Steadier hand-holding, since the camera gains a third point of contact with the user’s face, and the camera isn’t held out at arm’s length
- Easier video viewing in bright outdoor situations — where the LCD screen can sometimes be overwhelmed by sunlight, even at its brightest settings
See the Scene at an Exposure Level Similar to Actual Camera Settings
Exposure simulation is a menu setting with the EVF (and rear LCD screen) on mirrorless cameras — and it’s a feature many mirrorless users use frequently. It presents a view to the photographer that takes into account the camera’s actual exposure settings at the moment (ISO, shutter speed, and lens aperture), giving a view — before a picture is taken — that simulates what the finished, actual image will look like. And it will update immediately, if and when a photographer changes camera settings on-the-fly.

Exposure Simulation is an important capability in the EVFs on mirrorless cameras — again, something impossible with traditional optical viewfinders on DSLR. Nearly all Canon EOS mirrorless cameras have a Menu setting for Exposure Simulation. This means the scene you view in the finder will adjust its exposure to simulate how final exposure, at the camera settings you have in effect, will appear. Ever wonder how that deliberately under-exposed silhouette will actually appear, before you take the picture? Exposure simulation does exactly that, when it’s active. Raise or lower actual exposure, and the EVF adjusts to simulate how it’ll ultimately look. It’s a fantastic addition to an analog exposure compensation or manual metering scale in the viewfinder (which of course mirrorless cameras also have!).
OVF (Optical Viewfinder) Simulation
This is the type of scene where a relatively new Canon EVF feature, OVF simulation view assist, can make composing, judging exposure and focus easier. It reduces the extreme contrast that can be encountered in extremely bright sunlight, for instance, avoiding the tendency for the EVF to wash-out bright highlights and at the same time crush shadows or dark areas.

This is a recent addition to mid-range and high-end Canon EOS mirrorless cameras. One complaint sometimes mentioned by traditional DSLR users is that especially in very harsh lighting — such as sunlight on a clear, sunny day — the Electronic Viewfinder can occasionally be overwhelmed by the contrast range between brightest and dark shadow areas in a scene. In extreme situations, it can almost start to look like the scene is mostly pure whites and blacks.
In addition to Exposure Simulation, many (not all) recent EOS mirrorless models offer another Menu option: OVF simulation view assist. When activated, it changes how the EVF displays the brightest and darkest areas, regardless of other camera settings in effect. While this does not adjust overall finder brightness along with actual camera exposure settings (as Exposure Simulation does), it gives a view with consistent brightness that’s tailored to manage the contrast you see in the EVF. And while viewfinder brightness won’t change as camera exposure settings are adjusted, it will continue to vary overall brightness, as ambient light in the scene becomes brighter or darker. It’s worth trying, when you work with a mirrorless model so-equipped. And it directly addresses a complaint that used to be frequently leveled at mirrorless cameras by photographers who have worked with DSLRs.
View the Effect of White Balance, Picture Style Rendering, and More
Electronic viewfinders display adjustments like White Balance immediately, even as changes are made before the first shot is taken. In this instance, a deliberate applying of the Tungsten WB setting — in daylight — the EVF shows how the added cool, blue tones will look as you compose the scene.

Again, before you take a single shot, you can see in the finder an approximation of the effect of White Balance settings (even as you change them), the impact of Picture Style adjustments, and more. No guesswork, and no having to take test shots beforehand to confirm that your settings are appropriate.
Magnify the View in the Finder to Verify Critical Focus
In critical situations like macro images, nailing the exact plane of sharpest focus is often one of the photographer’s key tasks. EVFs provide the ability to magnify the view, right in the finder (and move the magnified section around the frame), to really assess whether critical focus has been achieved. With most Canon EOS R-series cameras, there’s a Menu setting to immediately provide a magnified view if the lens’s manual focus ring is moved after One-shot AF has locked focus on a stationary subject.

On higher-end EOS mirrorless cameras, like the EOS R6 and R5 series, there’s a rear button with a white magnifying glass icon. Assuming it hasn’t been customized for another purpose, press this — as you view a scene you’re about to photograph — and you magnify your view in two stages (pressing it a third time returns you to a normal full view of the scene). By default, this magnified view will occur wherever your active AF Area (AF point) is, or in the center of the screen if you’re set for Manual focus.
Or, in your camera’s AF menu, you can tell the camera to allow instant EVF magnification if you start to turn the lens’s focus ring for Manual focus, tweaking or totally over-riding AF. (Lens electronic MF > One-shot enabled [magnify])
Either way, for users who want to be able to really ensure sharpness with stationary subjects, this is a fantastic feature that can’t be duplicated on a DSLR before a shot is taken.
Raise or Lower Viewfinder Brightness
A frequent need, in bright sunlight, is to raise the overall brightness of the viewfinder — it’s not possible with the optical viewfinders in SLR cameras, but with the EVFs in mirrorless models, it’s usually an easy adjustment to make. And here’s another interesting EVF advantage: with the sun or extremely bright reflections of sunlight in the scene, there’s no risk of eye damage to the photographer looking through the finder — unlike an optical viewfinder, that sun is simply being viewed as the brightest white tone that the EVF can generate. This can be especially helpful to landscape and nature photographers in heavily back-lit compositions.

With DSLRs, there’s simply no way to change the overall brightness of your scene with the optical viewfinder. But most mirrorless cameras have exactly that, with the Viewfinder Brightness menu setting. It’s usually in the yellow-colored Set-up Menu, with Canon EOS mirrorless cameras. And this is entirely on top of the Exposure Simulation that we spoke of a moment ago. Whether you’re in bright sun, or a dimly-lit church, you can adjust the overall EVF brightness to align with your preferences.
Viewfinder Information, with EVFs
Electronic Viewfinders can display a host of live information, while you continue to view your subject or scene. Most of the following are in the red Shooting Menu, under Shooting info display. Here are a few user-selectable viewing options most Canon EOS mirrorless cameras offer, in the EVF:
- Histogram display
View a live histogram in the viewfinder, and watch it change as you either move the camera around a scene, or apply your own exposure adjustments. Most EOS cameras also give the option to display either a traditional brightness histogram, or an R-G-B histogram display (the latter can be useful in assessing White Balance, etc.). And there’s often another option for the histogram in the EVF to be displayed in a small or large size. - Electronic level
Usually listed among the multiple EVF display options under Screen info settings, this lets you toggle through different views when you press the camera’s INFO button. As you’d expect, the ability to view an actual level in the EVF can be very helpful in composing scenes, especially when you’re hand-holding the camera. - Distance scale
One thing experienced users are sure to notice on Canon’s RF-S and RF-series lenses for mirrorless cameras is that they don’t have an external window with a distance scale on the lens barrel. But there is an option to view this, directly in the Electronic Viewfinder. Usually in the red Shooting Menu, under Lens info display, are options to view Focus distance display, and you can usually select when this appears — anything from a full-time scale in the viewfinder (in feet or meters), to strictly as you turn the focus ring with the camera set for Manual focus. - Focal length display
This is likewise an option (on many EOS models) within the red Shooting menu’s Shooting info display > Lens info display choices. This lets you view a precise read-out of your lens’s actual focal length, with compatible lenses. It’s especially useful with zoom lenses, allowing you to verify your zoom settings without having to pull your eye away from the finder, and look at the lens barrel.
And, all this is in addition to the added information available on the left, right and bottom borders in the Electronic Viewfinder — by pressing the camera’s INFO button, you can toggle through different states from a totally clear finder display, to one that shows info currently in effect, including your Servo or One-shot AF, the file size (RAW, JPEG, and size of JPEG) you’re working with, video frame rates and resolution, White Balance setting, Picture Style setting, and even the type of AF Subject to Detect, if you have that active.
Summary
The first thing nearly any photographer experiences when they pick up a camera is how the world looks in their viewfinder. There’s nothing wrong with how this is done with DSLRs, as long as you’re in reasonable lighting. But mirrorless cameras open up a totally new door here, with what’s possible with the Electronic Viewfinder. Even if your personal preference is normally to have an uncluttered, plain display of your subject, you’ll see the benefits the first time you try to compose and shoot in a dimly-lit area. And the other options, which we’ve discussed here, can transform the way you interact with your camera. Long-time DSLR shooters, we urge you to look at all of this, the next time you handle a mirrorless Canon EOS camera!