Updated: Feb 3, 2019
With the recent release of full-frame mirrorless cameras by Canon, Nikon, Fuji and Panasonic to compete with Sony’s highly-respected A7 and A9 models, the question is:
Is the DSLR dead?
A Bit of History
The big difference between Mirrorless and DSLR’s is obviously the mirror. DSLR’s place a mirror in front of the sensor at a 45 degree angle to reflect the image received from the lens into the optical viewfinder (via a prism). Thus the image the photographer sees in the viewfinder is exactly the same as what the lens sees.
In this arrangement the mirror must be raised to allow the sensor to capture the image when the shutter button is pressed. By the way, the term reflex comes from reflection and refers to this mirror arrangement in front of the sensor.
This was superior to non-reflex cameras (like the rangefinder) which have a viewfinder to the side of the lens and give a slightly different view than that the one seen ‘through the lens’. This allowed for a wide range of interchangeable lens for the DSLR. In contrast, changing a lens on a non-reflex camera requires you to change both the lens and the viewfinder to accommodate for the different field of view.
Another advantage of this mirror arrangement is that is allows precise autofocusing due to a second optical path through the mirror to special auto-focus sensors. Typically there are two of these sensors which create two views of the focus point in a ‘stereo-like’ fashion. This is often called phase-based autofocus and when it was first rolled out by camera manufactures it greatly improved the autofocus accuracy.
Mirrorless cameras use the sensor to generate the view from the lens. This removes the need for a mirror and creates another type of “through-the-lens” viewing, although onto a screen rather than an optical viewfinder.
Early mirrorless cameras struggled with autofocusing because there was no room for the stereo-like autofocus sensors. Deprived of this phase-detection autofocusing, early mirrorless cameras used contrast for autofocus. The autofocus performance was underwhelming.
A breakthrough occurred when camera manufacturers developed a way to use phase-based autofocus directly from the main sensor. Sony capitalized on this and built the successful A7 series.
Sony’s mirrorless A7 and the newer A9 series is a serious challenge to the DSLR dominance. Canon, Nikon, Fuji and Panasonic have also recently released full-frame mirrorless cameras.
This has photographers asking is the DSLR is doomed?
Personally my opinion is no, at least not yet. After all, Nikon still sells the F6 a film SLR. But in the long run, I do believe the DSLR will be a minor player.
The Advantage of Mirrorless
If you cut through the marketing hype, the Mirrorless platform can offer three advantages to DSLR’s.
1) Faster lens. Mirrorless camera lens are free from the constraints of the mirror in DSLR which prevents the lens elements to be placed near the sensor. This allows lens to achieve larger (faster) apertures than are possible with a DSLR. Canon has a 28-70mm mirrorless camera lens at f/2. The largest aperture you can have on a 24-70 for DSLR is f/2.8.
2) Video is where it’s at. With phase detection autofocus, mirrorless have solved the auto-focus problems of plaguing early mirrorless cameras video capture. The DSLR loses all its advantages because the mirror needs to stay up during capture of video.
3) Fewer moving parts will (hopefully) improve life and lower cost of mirrorless cameras. The mirror adds more moving parts, complexity and weight to DSLRs. As mirrorless becomes the new norm for cameras, prices should come down because of the systems are smaller, simpler, easier to manufacture, and likely more durable.
You’ll notice I didn’t list weight as one of the advantages. While it is true the camera body of a mirrorless camera is less than its comparable DSLR, that weight advantage is reduced when you add a lens. I compared mirrorless cameras from Sony, Nikon and Canon with their DSLR counterparts paired with their native 24-70 mm lens. I was surprised to see that while mirrorless cameras save weight, in some cases the DSLR with lens combo was shorter when compared to the mirrorless model.
Besides, ergonomics are much more important than just weight and size. How does that camera feel in your hands? One complaint I’ve heard from early adopters of the mirrorless camera are that the lens need a tripod collar, and often lack them. It is feared that the larger lens put a strain on the flange of the mirrorless body because there is no way to mount the camera onto a tripod except by the camera body. Wasn't it Ansel Adams who answered the question "Which camera do you take out in the field?" with "The heaviest one I can carry."
In the end, DSLRs still have, in my opinion, a more pleasant viewfinder. But I have to admit, electronic viewfinders are getting better and are needed for video anyway. DSLRs still have slightly better autofocus but the gap is closing. That advantage disappears with video.
I suspect in ten years mirrorless will dominate the camera landscape, reducing the DSLR to a small but important share of camera sales.
I recently joined my friend Tony Avila in a podcast over at Aperture Priority to discuss this topic in a bit more depth. You can hear it here.
So, as Tony likes to say, open up that Aperture and let a little light in. And long live film!
About the author: JS Engelbrecht began his photography career in a High School dark room for the school's Year Book. Later he entered the fashion industry and product photography before turning his attention to Nature. "I moved from shooting pictures of beautiful jewelry to shooting pictures of natural beauty."
Now JS Engelbrecht enjoys capturing beautiful scenes during his travels. He is also a gifted teacher and guide for local photographers. Click here to see his fine art gallery.