When you get serious about photography, you face a choice: Do you buy a digital single-lens reflex (DSLR) camera or a mirrorless camera? You can get great photos with either, but each has its pros and cons.
DSLRs use the same design as the 35mm film cameras of days gone by. A mirror inside the camera body reflects the light coming in through the lens up to a prism (or additional mirrors) and into the viewfinder for you to preview your shot. When you press the shutter button, the mirror flips up, a shutter opens and the light falls onto the image sensor, which captures the final image. We’ll go through the features and capabilities of a this camera type one of our favorite intermediate-level DSLRs, the Nikon D5300.
In a mirrorless camera, light passes through the lens and right onto the image sensor, which captures a preview of the image to display on the rear screen. Some models also offer a second screen inside an electronic viewfinder (EVF) that you can put your eye to. One of the best affordable models that includes an EVF is Sony’s Alpha a600, which will use as our other example.
Here’s how the two technologies compare.
Size & Weight
DSLR camera bodies are comparatively larger, as they need to fit in the mirror and prism. The body of the $850 Nikon D5300 (see review), for example, is a rather bulky 3 inches deep. With the 18-55mm kit lens, the camera weighs about 1 pound, 2 ounces.
A mirrorless camera body can be smaller than a DSLR, with simpler construction. The $850 Sony a6000 (see review) has a body just 1.9 inches thick and weighs just over a pound with its 16-50mm kit lens.
Winner: Mirrorless Camera
You can carry a mirrorless camera more easily and fit more gear, such as extra lenses, into a camera bag.
DSLRs used to have the advantage here. The mirror mechanism directs light into dedicated autofocus sensors using a very quick technology called phase detection, which measures the convergence of two beams of light. Mirrorless cameras had been restricted to a system common on point-and-shoots called contrast detection, which uses the image sensor. This method moves the lens back and forth to find the position in which the image shows the highest contrast, which coincides with focus. Contrast detection is slower — especially in low light — than phase detection.
DSLR’s advantage is going away, due to the incorporation of phase-detection pixels into the image sensor on higher-end mirrorless cameras. These cameras utilize both phase and contrast detection to refine their autofocus. The Sony a6000, for instance, has 179 phase-detection points on its image sensor, while the Nikon D5300 has 39 in its separate AF sensor. Many mirrorless cameras still have only contrast-detection AF, however. If you are shopping for a mirrorless model that has fast autofocus, make sure that the camera maker specifies phase detection or hybrid autofocus.
The best mirrorless cameras match DSLRs for fast autofocus.
With a DSLR, the optical viewfinder shows you exactly what the camera will capture. With a mirrorless camera, you get a preview of the image on-screen, and sometimes also through an EVF, as with the Sony a6000.
When you’re shooting outside in good light, the preview in a mirrorless camera’s EVF will look close to the final image. But in situations where the camera is struggling (such as low light or with fast-moving subjects), the camera has to make some compromises to still display a real-time preview.
DSLRs can mimic a mirrorless camera by raising the mirror to show a live preview of the image. Most DSLRs are slow to focus in this mode, though, as they don’t have the hybrid on-chip phase-detection sensors and have to use slower contrast detection to focus.
For many situations, especially low-light shooting, the DSLR’s optical viewfinder is more accurate.
Shaky hands make for blurry pictures, and the effects are magnified the longer your zoom. Both DSLR and mirrorless cameras offer image-stabilization systems: Sensors measure camera movement, and the camera slightly shifts either part of the lens or the image sensor in a direction that’s opposite to the shake. Some mirrorless models shift both the lens element and the sensor in a synchronized pattern.
MORE: Best DSLRs
We have found that the differences between these approaches are minimal. Most can deal with a small amount of camera shake to produce a sharper picture, but can’t compensate for larger movements.
Image stabilization technology is equivalent in both camera types.
Both types of camera can take high-quality pictures, with similar resolutions and amounts of graininess, known as noise. Originally, mirrorless cameras’ smaller image sensors meant lower quality, as they couldn’t capture as much light. That is no longer the case. Camera manufacturers have learned to produce more sensitive chips and to better suppress noise. Furthermore, several mirrorless camera makers, such as Samsung and Sony, now use the same APS-C sensors found in the majority of DSLRs. Sony recently introduced its A7 line of cameras, which use the even larger full-frame sensor type found in the best professional DSLRs.
With equivalent sensors and equally good image processors, both camera types can take great photos.
Because of their on-chip focus sensors, higher-end mirrorless cameras are generally better-suited to video shooting. DSLRs can’t use phase detection with the mirror up while recording video, so they have to use the slower, less accurate, contrast-detection focus method. This leads to the familiar blur-blur look in the middle of a video when the camera starts hunting for the right focus. (An exception is Canon’s new DSLRs, such as the EOS 70D, which have phase-detection points on the image sensor, similar to a mirrorless camera.)
Some mirrorless cameras, such as the $1700 Panasonic GH4 and $1500 Samsung NX1, can capture 4K, or Ultra HD, video with four times the resolution of HD footage. The technology is likely to trickle down to lower-priced mirrorless models. Currently no DSLRs shoot 4K/Ultra HD video.
MORE: Smartphone vs. Mirrroless Camera: Face-Off
Video professionals, if they use a still-photo camera at all, tend to prefer DSLRs, because the cameras have access to a huge range of high-end lenses. Autofocus isn’t a concern for pros, who are skilled in manual focus. And they can often focus in advance, knowing where their subjects will stand in a scripted scene.
With superior autofocus in most models, mirrorless cameras provide the best results for most filmmakers.
Both camera technologies can shoot at very fast shutter speeds and capture a burst of images quickly. Mirrorless cameras are gaining the edge, though: The lack of a flapping mirror makes it easier to take image after image. The Sony a6000 can shoot 11 frames per second (fps), for example, while the Nikon D5300 can only do 5 fps. There are some faster DSLRs. The new Canon 7D Mark II shoots at 10 fps, but it costs $1800 (body only). Most mirrorless cameras use a mechanical shutter, as it produces better results. But they also have the option of using an electronic shutter (just setting how long the sensor reads the light signal) to achieve higher shutter speeds and shoot silently.
The simpler mechanics of mirrorless cameras allow them to shoot more photos per second, at higher shutter speeds.
Image & Video Playback
Both camera types can display images on their screens (typically measuring about 3 inches) or via an HDMI output to a television. Many DSLR and mirrorless models now include Wi-Fi for sending images to smartphones for online posting.
The method is identical in both cases.
Generally, DSLRs have longer battery life, as they can shoot without using the LCD screen or an electronic viewfinder, both of which consume a lot of power. The CIPA-standard battery life rating for the Nikon D5300 is 600 shots; the Sony a6000’s is just 360. However, all DSLRs and mirrorless cameras come with removable batteries, so you can carry a spare.
A DSLR allows you to shoot far longer on a single battery.
Lenses & Accessories
Choosing a DSLR gives you access to a plethora of lenses — from a number of manufacturers — ranging from cheap and satisfactory to professional and wildly expensive. Being a much newer format, most mirrorless models take only a small number of lenses from the camera maker, though the selection is slowly growing.
The proprietary mirrorless systems from manufacturers like Sony (A series), Pentax (Q cameras) and Samsung (NX series) have the fewest lenses, because these companies have only recently introduced mirrorless models. Sony offers 17 E-mount lenses, for instance, while Nikon has hundreds available for its DSLRs. Mirrorless cameras using the so-called Micro Four Thirds sensor format have the widest selection because they have been around the longest and come from several companies. Olympus and Panasonic make the cameras and lenses. But Sigma, Tamron and other companies also make Micro Four Thirds lenses.
You can generally purchase adapters to use DSLR-size lenses on a mirrorless camera that’s made by the same manufacturer (such as for Canon or Sony). But that often comes at a price of altering the focal length and zoom characteristics and sometimes disabling or slowing functions such as autofocus.
While mirrorless camera lenses cover the basics, DSLRs have access to a far greater variety.
If you regularly venture off the beaten path, it is worth looking at a model that adds an extra level of protection. Both DSLRS and mirrorless models offer this, such as the Pentax K50 DSLR and the Olympus OM-D EM-1 mirrorless camera (see review). Both have alloy bodies and are described as weatherproof, meaning that they can shrug off splashes. The Nikon 1 AW1 mirrorless model takes it a bit further, though: It is waterproof to an impressive depth of 49 feet.
Both camera types include mirrorless options.
The Bottom Line
Mirrorless cameras have the advantage of usually being lighter, more compact, faster and better for video; but that comes at the cost of fewer lenses and accessories. DSLRs have the advantage in lens selection and an optical viewfinder that works better in low light, but they are more complex and bulkier.
A mirrorless camera is better for a casual to semi-serious photographer who wants an all-day carry camera. A serious or pro shooter who wants access to a wider range of lenses and other gear would be better off with a DSLR. One area where there is no difference is image quality. Both modern DSLR and mirrorless cameras can take excellent photos.