Mirrorless vs DSLR
There’s a new battle in the photo world and it is between DSLR and Mirrorless technologies. In the past, it was the big Nikon vs. Canon debate and DSLR was the technology that ruled them all. This time the lines seem to be drawn between the “second tier” photographic companies like Panasonic/Fuji/Sony and Canon/Nikon. The two camera giants having one failure in common: Both Canon and Nikon have unsuccessfully attempted to produce a mirrorless camera.
Canon’s offering was the wildly unsuccessful EOS M. Nikon came out with the 1 series, which also did not set the sales world alight. Was anything specifically wrong with their products? I don’t think so, but the problem was that companies like Sony, Panasonic, and Fuji were further down the mirrorless road and their products were slightly more competitive than Canon and Nikon’s. Also, neither one of the two behemoths appear motivated enough to improve on their initial mirrorless attempts.
To explore this new battle further, let’s first take a look at how a DSLR camera works, how mirrorless cameras work, and then ponder the question: Why do we still need a camera with a mirror inside?
How a DSLR Camera Works
In DSLRs, after entering into the camera body, the light hits a tilted mirror inside the camera. The light reflects off the mirror upwards into the focusing screen. Do you remember those old cameras where the person looked downwards into the camera at the focusing screen to see the subject? This position is, of course, not a very convenient way to view and shoot pictures from. In modern DSLRs, there is an additional prism that catches the light after it has gone through the focusing screen, where it bounces off many sides and eventually gets to the eyepiece.
The system that DSLRs use for shutter is called focal plane shutter. Between the mirror and the sensor behind it, there are a couple of curtains. When you click the capture button of the camera, the mirror goes up and light moves forward to reach the curtains. The first curtain gets out of the way to expose the light onto the sensor. When the exposure time is complete, the second curtain comes up and covers the sensor. The combination of curtains is used to ensure an exposure that provides the same amount of time to each pixel on the sensor.
How a Mirrorless Camera Works
As the name suggests, mirrorless cameras do not have a mirror in the way. The mirrorless cameras have an electronic viewfinder that shows exactly what falls onto the sensor. The light passes through the lens and enters into the camera body where it directly hits the image sensor, which is connected to an electronic viewfinder, forming a digital image on the electronic viewfinder. The view you see in the viewfinder of a mirrorless camera is from that electronic viewfinder.
Some of the mirrorless cameras also use a focal plane shutter system, but the mechanism is a little different. The curtains are already open so you can view through the electronic viewfinder at all times. But when you click the capture button, the first curtain comes down and covers the sensor. The exposure starts when it opens again. After the exposure time, the second curtain closes and finishes the exposure time and again opens to retain the viewing from the electronic viewfinder. Some of the mirrorless cameras also have an electronic shutter system which starts recording with the switching on of a recording command. It is simply like an on and off switch that enables and disables recording while the light keeps hitting the camera sensor at all times.
Advantages of a DSLR System
- The basic advantage of the DSLR is that it is one the most dominant and widely adapted systems in the photographic world right now.
- Because it gives the real image of the scene (as the human eye sees it with the actual light of the scene directed to the eye), we get a real sharp and clear view of the frame from the viewfinder. One basic advantage is that it enables the photographer to have a great view even in low light conditions as the human eye adapts amazingly with dark environments—DSLR viewing feels more natural in night time photography.
- DSLRs are better for action photography because their viewing system gives an excellent stroboscopic effect while performing panning shots.
- The focal plane shutter system used in DSLR is a very established technology that simplifies the design of the camera. Using this mechanism ensures some amazingly fast shutter speed values. The shutter in DSLRs has to do half the work in comparison to mirrorless cameras, which have a focal plane shutter mechanism.
Disadvantages of a DSLR System
- The mirror and the mirror housing take a lot of space in the camera body, making the whole camera bulkier and heavier.
- Whatever settings you have applied in terms of ISO, aperture, exposure, and white balance, you are unable to see those settings in the viewfinder. All you get through the viewfinder is an overview of the frame with no real indication of how the picture will come out of the camera. For this reason, the photographer has to keep shooting and looking at the LCD to see what he is actually capturing. This viewing system provides very limited digital assistance.
- Autofocus speeds: DSLRs use a technology called phase detection that is much faster than contrast detection (as used by most mirrorless cameras). But as technology has caught up, mirrorless cameras are now also starting to employ this technology, so in actual fact, we can ignore focus speeds as the playing field is starting to level out. (Or is already level if you look at the new Sony Alpha a6000 versus almost any DSLR.)
- When taking a photo, the mirror has to flip up for a short time while the shutter is open. When taking video, the mirror needs to be flipped up for the whole time the camera is recording. While the mirror is flipped up, a DSLR cannot employ the phase detection system of focusing and has to use contrast detection, which does not work as well. Therefore, focusing in video suffers to a degree. Some of the newer DSLRs have started employing mirrorless technologies by using phase detection while recording video.
Advantages of a Mirrorless System
- No mirror is needed, which reduces the size and weight of the camera. Bringing the lens closer to the sensor by removing mirror box housing also enables the use of many other lenses through the use of lens adaptors.
- What you see through the viewfinder is what you get as a final image. It also enables the camera to use many digital features like digital focus and an immediate live view of custom ISO and aperture settings.
- For video, phase detection technology can be employed (described above under the disadvantages of DSLR), meaning a sharp autofocus while the camera is recording.
- It can take a burst of images faster as there is no mirror to flip up and down with each shot.
- It removes the shutter vibration issue for macro photographers.
- It is more silent than DSLRs, which is great for street photography and anywhere you don’t want to hear a loud mechanical click.
Disadvantages of a Mirrorless Viewing System
- An electronic representation of the real-life image is not that bright as viewing through the human eye.
- The electronic viewfinders are far lower in resolution, which is another big disadvantage and makes the viewing experience a little less smooth.
- It increases the consumption of power, which reduces the battery time of the camera.
My guess is that in the future, DSLRs will remain in the domain of the serious professional and will always occupy a niche, much like medium and large format photography occupy a niche today. DSLRs are one the most stable and dominant systems of cameras used worldwide. However, we will see the question “Is a Mirror Still Needed in a Camera?” asked a lot more in the future. Looking at the advantages that mirrorless brings to the table, we can see why the inevitable shift to mirrorless has already started. These advantages include the following:
- faster burst speed photography
- less noise
- less vibration
- a what-you-see-is-what-you-get electronic image on the sensor
- longer battery life as technology improves
The future therefore might look bright – even through an electronic viewfinder?