In a DSLR camera, a mirror inside the camera body reflects light coming through the lens up to a prism and into the viewfinder. When you press the shutter button, the mirror flips up, the shutter opens, and the light hits the image sensor to capture the final image.
In a mirrorless camera, light passes through the lens and onto the image sensor which captures a preview of the image to display on the rear screen.
How do DSLR and mirrorless compare?
- Autofocus Speed: DSLR cameras used to have the advantage because they use phase detection which quickly measures the convergence of two beams of light. Mirrorless used to use contrast detection which is slower, especially in low light. Since mirrorless cameras now have phase detection, neither type of camera has the advantage.
- Availability of Lens: Currently, DSLRs have access to a wider ranges of lenses; however lens choices are quickly growing for mirrorless cameras.
- Battery Life: If you don’t use the LCD screens to preview and view images, DSLRs offer longer battery life. Otherwise, battery life is similar.
- Image Quality: Until recently, mirrorless cameras had small image sensors which couldn’t capture as much light. Now, the chips are more sensitive and capture as much light as those in DSLRs.
- Image Stabilization: Image stabilization technology is equivalent in both types of cameras. (There are a few mirrorless cameras that offer 5-axis image stabilization which is superior; however, they are costly, $2,000+.)
- Previewing Images: If you shoot mostly in good light, both types of cameras will perform well. If you often shoot in low light, a DSLR will be easier to use.
- Shooting Speed: The simpler mechanics of mirrorless cameras allow them to shoot more photos per second at higher shutter speeds.
- Size and Weight: Generally, DSLR cameras weigh more and are bulkier than mirrorless cameras. You can carry a mirrorless camera more easily and fit more gear into your camera bag.