A DSLR is a digital single-lens reflex camera, which uses a mirror to send the view through the lens up to an optical viewfinder. When you press the shutter, the mirror flips out of the way so light reaches the sensor and records the photo. It is a camera type with interchangeable lenses and a long history.
How a DSLR Works
- Light enters through the lens and hits an angled mirror inside the body.
- The mirror reflects that light up into a prism, which flips the image the right way round and sends it to the viewfinder.
- You see the scene directly through the lens, with no screen delay.
- When you press the shutter button, the mirror swings up, the shutter opens, and light reaches the sensor.
- The shutter closes, the mirror drops back, and the image is saved to the memory card.
That moving mirror is the cause of the familiar clack sound of a DSLR. A separate autofocus module, usually under the mirror, measures focus while you look through the viewfinder.
Key Features of a DSLR
- Optical viewfinder: a clear, lag-free view that does not use battery power.
- Interchangeable lenses: a wide choice of lenses, including many older ones available used.
- Larger body: the mirror box and prism add size and weight.
- Battery life: often long, because the viewfinder is not electronic.
- Manual controls: dedicated dials and buttons for common settings.
DSLR Compared with Mirrorless
| Trait | DSLR | Mirrorless |
|---|---|---|
| Viewfinder | Optical, through a mirror | Electronic screen |
| Body size | Usually larger | Usually more compact |
| Battery life | Generally long | Generally shorter |
| Video features | Often more limited | Often more advanced |
| Current focus of makers | Mature, fewer new models | Main area of development |
Both types use the same basic principles of aperture, shutter speed and ISO, so the skills you learn carry across.
Who Might Choose a DSLR
Choose a DSLR if you like an optical viewfinder, want long battery life, or want to use a large collection of lenses. Shoppers looking at used gear often find DSLR bodies and lenses easy to come across. If you want a lighter kit or advanced video, a mirrorless camera may fit better. Check the maker’s pages for current model details.
FAQ
Is a DSLR still worth using?
Yes, if it suits your style. Photos depend on lenses, light and technique, and a DSLR can capture excellent images.
What does single-lens reflex mean?
It means one lens is used both to form the image on the sensor and to show it to you in the viewfinder, with a mirror redirecting the light.
The Short Version
A DSLR uses a mirror and prism to show you the scene through the lens, then flips the mirror aside to record the photo. It offers an optical view, interchangeable lenses and long battery life. Choose it for those strengths, or consider mirrorless for size and video.
