In DSLR, a mirror inside the camera body reflects the light coming in through the lens up to a prism, 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. Mirrorless cameras take a different approach. They use the ‘live view’ captured by the camera sensor itself to create an electronic viewfinder image. By doing this, they dispense with the need for a mirror and an optical viewfinder altogether.
Comparison of Mirrorless and DSLR camera
- Size & Weight
DSLR camera bodies are comparatively larger, as they need to fit in both a mirror and a prism. A mirrorless camera body can be smaller than a DSLR, with simpler construction.
- Autofocus Speed
DSLRs use phase detection to quickly measures the convergence of two beams of light. Mirrorless cameras also have both phase and contrast detection sensors built into the image sensor, and can use both to refine their autofocus.
- Previewing Images
With a DSLR, the through-the-lens 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.
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.
- Battery Life
Generally, DSLRs offer longer battery life because they have the ability to shoot without using the LCD screen or EVF, which use a lot of power.
- Shooting Speed
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.
- Video Quality
Because of their on-chip focus sensors, higher-end mirrorless cameras are generally better suited to video shooting. Most 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.
- Image Quality
Both types of camera can take high-quality pictures, with similar resolutions and amounts of graininess, known as noise. With equivalent sensors and image processors, both camera types can take great photos.