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 with our top DSLR pick, the $446 Nikon D3300.
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. Our example of a mirrorless camera, one of our favorites, is Sony's $598 Alpha a5100.
Here's how the two technologies compare.
Size & Weight
DSLR camera bodies are comparatively larger, as they need to fit in both a mirror and a prism. The body of the Nikon D3300, for example, is a rather bulky 3 inches deep before you put the lens on the front. With the 18-55mm kit lens, the camera weighs about 1.1 pounds.
A mirrorless camera body can be smaller than a DSLR, with simpler construction. The Sony a5100 has a body just 1.6 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.
MORE: Best Mirrorless Cameras
DSLRs used to have the advantage here, because they use a technology called phase detection, which quickly measures the convergence of two beams of light. Mirrorless cameras were restricted to a technology called contrast detection, which uses the image sensor to detect the highest contrast, which coincides with focus. Contrast detection is slower — especially in low light — than phase detection.
This is no longer the case, though, as mirrorless cameras now have both phase and contrast detection sensors built into the image sensor, and can use both to refine their autofocus. The Sony a5100, for instance, has 179 phase-detection and 39 contrast-detection points on its image sensor, while the Nikon D3300 has 39 phase-detection sensors in its separate AF sensor, and uses the entire image sensor for contrast detection.
Both types offer speedy autofocus, with mirrorless cameras offering hybrid sensors that use both phase and contrast detection on the sensor.
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. Some mirrorless cameras offer an electronic viewfinder (EVF) that simulates the optical viewfinder.
When you're shooting outside in good light, the preview on the screen or EVF of a mirrorless camera will look close to the final image. But in situations where the camera is struggling (such as in low light or with fast-moving subjects), the preview will suffer, becoming dull, grainy and jerky. That’s because the mirrorless camera has to slow down the speed at which it captures images to grab more light, but still has to show you a moving preview. A DSLR, by contrast, reflects the light into your eye, which is better than the camera sensor at low light.
DSLRs can mimic a mirrorless camera by raising the mirror and showing a live preview of the image (usually called Live View mode). Most low-cost 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.
So, if you are shooting mostly in good light, both types will perform well. If you are often shooting in low light or other challenging conditions, though, a DSLR will be easier to shoot with.
For many situations, especially low-light shooting, the DSLR's optical viewfinder is better.
Shaky hands make for blurry pictures, and the effects are magnified the longer your shutter speed, or the more you zoom in. 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 the differences between these approaches are minimal. The main advantage of sensor stabilization is that it works with all lenses. Lens stabilization only works with lenses that have it built in, which are often more expensive. Either way, most modern cameras 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. Mirrorless cameras' smaller image sensors used to mean lower quality (as they couldn't capture as much light), but 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's A7 line of cameras use the even larger full-frame sensor type found in the best professional DSLRs.
With equivalent sensors and 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. However, some newer SLRs are adding phase detection on the sensor, such as the Canon 70D and the Rebel T6i.
Increasingly, mirrorless cameras, such as the Sony A6300 and the $1,500 Samsung NX1, can capture 4K, or Ultra HD, video with four times the resolution of HD footage. The technology is slowly trickling down to lower-priced mirrorless models. Currently, only higher-end DSLRs, such as the Nikon D5, shoot 4K/Ultra HD video. 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 because 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. With the exception of high-end DSLRs, mirrorless cameras have an edge, though: The lack of a mirror makes it easier to take image after image. The Sony a5100 can shoot 6 frames per second (fps), for example, while the Nikon D3300 can do only 5 fps. Although they don’t have mirrors, most mirrorless cameras still use a mechanical shutter, where a physical shutter lifts to expose the image, as it produces better results. They also have the option of using an electronic shutter (just setting how long the sensor reads the light), which means they can shoot quicker and 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 now include Wi-Fi for sending images to smartphones for online posting, a feature that is present on the Sony A5100.
Both types offer large screens and video outputs, and some offer Wi-Fi connections to smart phones for quick image-sharing.
Generally, DSLRs offer longer battery life, as they can shoot without using the LCD screen or an electronic viewfinder, both of which consume a lot of power. However, both types will have similar battery lives if you use the LCD screens to preview and view captured images a lot, as this consumes a lot of power. However, all DSLRs and mirrorless cameras come with removable batteries, so you can carry a spare.
DSLRs offer the ability to shoot without using the LCD screen or EVF, which can extend the battery life.
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. Mirrorless models are more restricted, offering access to a small number of lenses from the camera maker, though the selection is 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 such as the Olympus PEN series using the Micro Four Thirds sensor format have the widest selection of mirrorless cameras because they have been around the longest and are available 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.
DSLRs offer access to the wider range of lenses, but the gap between the two types is narrowing as more mirrorless lenses become available.
If you regularly venture off the beaten path, it's 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. Both have alloy bodies and are described as weatherproof, meaning that they can shrug off rain and other splashes. The Nikon 1 AW1 mirrorless model takes it a bit further, though: It’s waterproof to an impressive depth of 49 feet.
Both types offer models that are hardened against the elements.
Mirrorless cameras have the advantage of usually being lighter, more compact, faster and better for video; but that comes at the cost of access to 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 a lighter kit to carry around all day. A serious or pro shooter who wants access to a wider range of lenses and other gear would be better off with a DSLR.
|Model||Nikon D3300||Sony a5100|
|Included Lens||18-55mm f/ 3.5-5.6||16-50mm f/3.5-5.6|
|Weight (with lens)||1 lb 2.7 oz||14 oz|
|Size||4.9 x 3.9 x 3 inches||4.8 x 2.5 x 1.6 inches|
|Autofocus||11 Contrast detection in housing||179 phase detection, 25 contrast on sensor|
|Preview||Optical viewfinder; 3-inch LCD||3-inch tilting LCD|
|Video Quality||Excellent, slow autofocus||Excellent, fast autofocus|
|Speed||5 fps ||6 fps|
|Image Resolution||24.2 Megapixels||24.3 Megapixels|
|Video Resolution||Up to 1080p, 60fps||Up to 1080p, 60fps|
|Image Stabilization||In kit lens (and select other lenses)||In kit lens (and select other lenses)|
|Lens & Accessories||Hundreds: All Nikon DX format, many other types||17 Sony A-mount|
|Battery Life (CIPA)||600 (using viewfinder)||400|
|Related Buying Guides:|
|How to Choose the Right Camera|
|Best DSLR Cameras|
|Best Mirrorless Cameras|