Lens mountA bayonet ring: the lens turns and locks into place.
Mirror (reflex mirror)Flips up at the moment of exposure, clearing the way.
Lens release buttonUnlocks the lens so it can be turned off.
Self-timer lamp (AF-assist lamp)Blinks during the self-timer countdown; also lights dim scenes.
Strap mount (strap eyelet)One on each side of the body.
Back 8
Viewfinder eyepieceShows the scene through the lens, via mirror and prism.
EyecupRubber that shades the eyepiece and cushions your eye.
Diopter adjustmentSharpens the viewfinder for your own eyesight.
Screen (monitor)Shows menus, the live view and the pictures taken.
Menu buttonOpens the camera's settings menus.
Playback buttonShows the pictures already taken.
Info buttonShows or hides the shooting information.
Memory card slot coverOpens to the slot for the memory card.
Top and bottom 9
LensGlass elements that focus the picture onto the sensor.
Shutter button (shutter-release button)Half-press to focus, press fully to take the picture.
Power switchTurns the camera on and off.
Mode dialPicks the shooting mode: auto, program, priority or manual.
Command dial (main dial)Changes the setting for the chosen mode, such as shutter speed.
Hot shoe (accessory shoe)Takes a flash; its contacts carry the firing signal.
Focal plane markShows where the sensor lies, for measuring focus distance.
Tripod socketScrews onto a tripod or other support.
Battery compartment coverOpens to the battery, which sits inside the grip.
Inside: the light path 4
Focusing screenA matte screen the viewfinder picture forms on.
PentaprismTurns the picture the right way round for the eyepiece.
ShutterOpens for a set time to let light reach the sensor.
Image sensorTurns the light into the digital picture.
How this list was compiled: Read 2026-09-26. (1) A camera maker's online manual for an entry-level digital SLR, Getting to Know the Camera, https://onlinemanual.nikonimglib.com/d3500/en/02_introduction_01.html : power switch, shutter-release button, mode dial, lens release button, mirror, lens mount, AF-assist illuminator and self-timer lamp, accessory shoe, command dial, eyelets for camera strap, focal plane mark, rubber eyecup, viewfinder eyepiece, diopter adjustment control, playback, menu and information buttons, memory card slot cover, battery-chamber cover, tripod socket, monitor. (2) A second maker's online manuals, Part Names, for two mirrorless cameras, https://cam.start.canon/en/C003/manual/html/UG-00_Before_0090.html and https://cam.start.canon/en/C005/manual/html/UG-00_Before_0090.html : shutter button, main dial, self-timer lamp/AF-assist beam, grip (battery compartment), lens mount, hot shoe, lens release button, power switch, strap mount, focal plane mark, shutter curtain/image sensor, eyecup, viewfinder eyepiece, menu button, info button, playback button, dioptric adjustment knob, screen, tripod socket, card slot cover, battery compartment cover, mode dial. (3) Wikipedia, Digital single-lens reflex camera, https://en.wikipedia.org/wiki/Digital_single-lens_reflex_camera : the mirror at 45 degrees sends light over a matte focusing screen and a pentaprism or pentamirror to the viewfinder eyepiece, and to the image sensor when the shutter release is pressed. (4) Britannica, Viewfinder, https://www.britannica.com/technology/viewfinder : in a single-lens reflex the mirror reflects the image to a ground-glass focusing screen, seen through a pentaprism that corrects its reversal; the mirror moves out of the way at the moment of exposure. Licence: own work
The drawing: Drawn for this site by script, 2026-09-26. Licence: own work
How it works
These parts of a DSLR camera are drawn on one generic body in four panels. Start with the 8 main parts, or pick a panel: the controls outside, or the light path inside, from lens to sensor.
Read the full guide
Parts of a digital camera, inside
Light passes through the lens to the mirror, which sends it up through the focusing screen and the pentaprism to the eyepiece. Press the shutter button and the mirror flips up, the shutter opens, and the light falls on the image sensor.
Two names for one part
Makers name some controls differently: command dial or main dial, accessory shoe or hot shoe, monitor or screen. Under Name it, either name is right.
Questions and answers
What are the main parts of a camera?
The lens, which focuses the light; the lens mount it locks into; the shutter button; the mode dial; the viewfinder eyepiece and the screen, to see the picture; and the image sensor, which records it.
Does a mirrorless camera have the same parts?
Outside, mostly: lens mount, shutter button, dials, hot shoe, screen, eyepiece and sensor. Inside it has no mirror, focusing screen or pentaprism. Light goes straight to the sensor, and the eyepiece shows a small electronic screen.
What does the focal plane mark show?
The circle crossed by a line on the top plate marks where the image sensor lies inside the body. Focus distances are measured from that plane, not from the front of the lens.