Camera Words, Explained Normally

Camera types

DSLR: A digital camera with removable lenses and a mirror inside. Look through its optical viewfinder and you see through the lens.
Why it matters: Test the body and lens separately. The mirror, shutter, focus system and lens mount add their own failure points.
Mirrorless: A digital camera with removable lenses but no DSLR-style mirror. You frame with the rear screen or an electronic viewfinder.
Why it matters: The sensor is more directly exposed when the lens is off; EVF, battery life and in-body stabilization may matter.
Compact: A small camera with a lens permanently built in, often retracting into the body when switched off. Also called a pocket camera or point-and-shoot.
Why it matters: A failed lens mechanism can effectively write off the whole camera.
Bridge camera: A DSLR-shaped camera with a large built-in zoom lens. Despite the shape, the lens normally does not come off.
Why it matters: Test that long zoom repeatedly and across its entire range.

Exposure

Aperture: The adjustable opening inside a lens. A low f-number such as f/2.8 means a wider opening; f/8 is smaller.
Why it matters: Aperture changes brightness and how much appears sharp. Small apertures also reveal sensor dust more clearly.
Stop down: Choose a smaller aperture: for example, change from f/2.8 to f/8. The number gets larger while the opening gets smaller, because photography enjoys a practical joke.
Why it matters: Use it for the plain-wall sensor-dust test.
Shutter speed: How long the camera records light. 1/1000 second can freeze movement; 1/15 second may blur if your hands move.
Why it matters: Compare stabilization on and off at a slower speed, and make sure the camera exposes consistently.
ISO: A brightness or sensitivity setting. Higher ISO makes low-light shooting easier but usually adds grain-like noise and reduces image quality.
Why it matters: Noise at high ISO is normal; fixed bright lines and severe colour blocks are not.
Focal length: The number in millimetres on a lens. Shorter focal lengths show a wider scene; longer ones make distant subjects appear larger.
Why it matters: Test a zoom at both ends—wide and telephoto—because faults may appear only in part of its range.

Focus and viewing

Autofocus / AF: The camera and lens move glass elements to make the selected subject sharp. A focus point is the area the camera tries to make sharp.
Why it matters: Repeat near-to-far focusing and inspect files; one confirmation beep is not proof of accurate focus.
EVF: Electronic viewfinder—the small screen you look through instead of using the rear display.
Why it matters: Check for flicker, dead areas, poor colour and unreliable automatic switching.
Optical viewfinder: A viewfinder that uses glass and, in a DSLR, a mirror rather than a miniature screen.
Why it matters: Dust in the viewfinder usually does not appear in photographs, but a sticking DSLR mirror can affect operation.
Dioptre: The little eyesight-adjustment control beside many viewfinders. It changes viewfinder sharpness without changing the photograph.
Why it matters: A wrongly set dioptre can make a healthy camera appear unable to focus. Adjust it before judging.

Sensor and files

Sensor: The light-sensitive chip that records the image—the digital equivalent of film.
Why it matters: Dust, stuck pixels, corrosion or electronic failure can affect every photograph.
CCD: An older type of image sensor used in many early digital cameras. It can produce pleasing results; it does not contain a magical colour generator.
Why it matters: Buy the camera for its actual files and condition, not three letters in a listing.
CMOS: The sensor technology used in most newer cameras and some older ones. Sensor type alone does not rank image quality.
Why it matters: Judge samples, condition and suitability rather than treating CCD versus CMOS as a winner-takes-all contest.
Crop sensor / full frame: Full frame means a sensor roughly the size of 35 mm film. A crop sensor is smaller, so the same lens shows a narrower view.
Why it matters: It affects lens choice, camera size and low-light behaviour—not whether a camera is automatically good.
RAW: A minimally processed image file with more editing flexibility and a larger file size. It often needs compatible software before sharing.
Why it matters: Confirm the model’s RAW files still open in software you can use.
JPEG: A processed, compressed image file that is ready to view and share. Nearly every digital camera makes one.
Why it matters: JPEG samples are convenient, but heavy in-camera processing can hide what the sensor originally recorded.
EXIF / metadata: Information stored inside an image file, often including camera model, lens, date and exposure settings.
Why it matters: It can help confirm a remote sample came from the claimed camera, though it can be removed or edited.
Shutter count: The number of shutter releases a camera reports. Some models expose it reliably; others do not.
Why it matters: It adds context, not a condition score. Low count cannot disprove corrosion, impact or poor storage.

Lens condition

Fungus: Growth inside a lens, often resembling fine branches, threads or a web under angled light.
Why it matters: It can lower contrast, damage coatings and be expensive to remove. A few ordinary dust specks are usually less important.
Haze: A misty veil inside a lens caused by vapour, lubricants or degraded materials.
Why it matters: Strong haze can make every image look washed out and may require dismantling the lens.
Lens separation: The adhesive between joined glass elements is failing. It may look like rainbow patches or an irregular boundary near an edge.
Why it matters: It is not surface dirt and is rarely fixed by normal cleaning.
Decentering: One or more lens elements sit slightly out of alignment. Photograph a detailed flat scene straight-on; one side may remain much softer than the other.
Why it matters: It can follow an impact and may make an otherwise clean lens disappointing.
Stabilization: A system that counters hand movement. Optical stabilization moves part of the lens; in-body stabilization moves the sensor.
Why it matters: It helps at slower shutter speeds, but old mechanisms can fail or make abnormal noises.
IBIS: In-body image stabilization: the camera moves its sensor to counter hand shake, so it can work with many lenses.
Why it matters: Test it on and off. Errors, violent rattling or consistently worse results when enabled suggest trouble.

Storage

SD / SDHC / SDXC: Generations of the same-shaped memory card. Original SD usually reaches 2 GB; SDHC covers higher capacities; SDXC goes higher again and uses a different standard.
Why it matters: An old camera may reject a card that fits perfectly. Check its manual before buying storage.
CompactFlash: A chunky card common in older professional and enthusiast cameras. The camera socket contains many thin pins.
Why it matters: Inspect for bent pins and insert cards straight. Readers are still available but may be an extra purchase.
xD-Picture Card: A small proprietary card used mainly by older Olympus and Fujifilm cameras.
Why it matters: Capacity, availability and price can turn a cheap compact into a nuisance.
Memory Stick: Sony’s family of proprietary cards, produced in several shapes and generations.
Why it matters: Identify the exact variant; “Memory Stick” alone may not tell you what fits.
Card reader: A small device that lets a computer or phone read a memory card directly.
Why it matters: It may be easier and safer than relying on an obsolete camera cable.

Other hardware

Lens mount: The metal or plastic fitting where a removable lens locks onto a camera body. Different systems are not normally interchangeable.
Why it matters: Look for dents, loose movement, damaged contacts and impact marks.
Hot shoe: The bracket with electrical contacts on top of many cameras for an external flash or accessory.
Why it matters: Corrosion or bent rails can prevent accessories mounting or communicating correctly.
Megapixels: Roughly how many million pixels are in an image. More can allow larger prints or cropping, but tells you little about colour, noise, focus, lens quality or usability.
Why it matters: It is not a simple quality ranking, especially across cameras of different ages and sensor sizes.