A mirror in a digital camera is a key component of Digital Single-Lens Reflex (DSLR) cameras, not all digital cameras. It's not present in mirrorless cameras. The mirror's function is to reflect the light coming through the lens upwards into the optical viewfinder (OVF), allowing the photographer to see the scene directly before taking a picture.
How the Mirror Works in a DSLR
- Position: The reflex mirror sits at a 45° angle behind the lens.
- Function: It reflects the incoming light to the pentaprism in the viewfinder.
- Mechanism: In most DSLRs, the mirror is a moving part. When a photo is taken, the mirror flips up out of the way, allowing the light to hit the image sensor.
The Absence of Mirrors in Other Digital Cameras
- Mirrorless Cameras: As the name implies, mirrorless cameras do not use a mirror. They use an electronic viewfinder (EVF) or the rear LCD screen for composing the shot. The image seen in the EVF is a digital representation, created by the camera's image sensor.
Types of Mirrors in Different Contexts
It's important to note that the term "mirror" can refer to different components within the broader context of digital imaging technologies:
- DSLR's Reflex Mirror: This is the physical mirror discussed above.
- Digital Rear-View Mirrors (in vehicles): These are cameras that project a digital image of the scene behind the vehicle onto a screen. This is a completely separate technology from the reflex mirror in a DSLR camera.
While some digital cameras might use mirrors in other optical systems (e.g., some telephoto lenses), the primary context for a "mirror" in a digital camera relates to the mechanism within DSLR cameras.
