Camera: smartphone terms explained

31 terms. Back to the full glossary.

Camera sensor size: The physical size of the image sensor, written as an optical format such as 1/1.3 inch or 1 inch (bigger fraction = bigger sensor). Larger sensors collect more light. The inch figure is a historic label and is not the true diagonal, so use it only to compare. Larger sensors typically help in low light and give more natural background blur. Software processing narrows the gap, so sample photos beat spec sheets. Related: Megapixels, Pixel binning, Aperture, Pixel size.
Megapixels (MP): The number of pixels the sensor has, in millions. More megapixels allow larger prints and more cropping but do not by themselves mean better photos. Photo quality depends on sensor size, lens, processing and stabilisation. High-megapixel sensors usually combine pixels in low light and output a smaller image. Treat a very high number on a small sensor as marketing. Related: Pixel binning, Quad-Bayer (and similar) sensors, Camera sensor size, Pixel size.
Pixel size (micrometres): The width of a single pixel on the sensor, in micrometres. Larger pixels gather more light each. When pixels are binned together, the effective pixel size grows, for example four 1.0 micrometre pixels act like one 2.0 micrometre pixel. Compare the binned size when judging low-light ability. Related: Pixel binning, Camera sensor size, Megapixels.
Pixel binning: Combining neighbouring pixels into one larger effective pixel to capture more light, at the cost of a lower output resolution. A 50MP sensor with 4-in-1 binning typically outputs around 12MP photos with better low-light quality. Binning explains why a very high megapixel sensor usually saves ordinary photos at a lower resolution. The full-resolution mode is best in bright light. Related: Quad-Bayer (and similar) sensors, Megapixels, Pixel size, Night mode.
Quad-Bayer (and similar) sensors: A sensor layout where groups of four (or nine or sixteen) neighbouring pixels share the same colour filter, which makes binning possible. It lets one sensor act as a high-resolution camera in bright light and a large-pixel camera in low light. Remosaic processing at full resolution can reduce sharpness slightly versus a true high-resolution sensor. Related: Pixel binning, Megapixels, Camera sensor size.
Aperture (f-number): How wide the lens opening is. A lower f-number such as f/1.7 lets in more light than f/2.4. A wider aperture helps in low light and gives a shallower depth of field. Small sensors can only do so much with it. Some phones have a variable aperture, but most are fixed. Related: Camera sensor size, Focal length, Night mode, OIS.
Focal length (35mm equivalent): How wide or tight the view of a lens is, quoted as the equivalent on a full-frame camera so lenses can be compared. A smaller number is wider. A main camera is typically around 23 to 28mm equivalent, an ultrawide around 12 to 16mm, and a telephoto from about 60mm up. Dividing a telephoto's equivalent length by the main camera's gives the optical zoom ratio. Related: Optical zoom, Telephoto camera, Ultrawide camera, Aperture.
OIS (optical image stabilisation): A mechanism that physically moves the lens or sensor to cancel hand shake, helping low-light photos and video. EIS (electronic stabilisation) does this in software by cropping the frame. OIS is most valuable on the main and telephoto cameras. It allows longer exposures without blur at night. Check which cameras have it, because many phones have it only on the main one. Related: EIS, Night mode, Telephoto camera, Video resolution and frame rate.
EIS (electronic stabilisation): Software stabilisation that uses the gyro and crops the frame to smooth out shaky video. It works well in good light but crops the view and can look artificial in low light. Phones with both OIS and EIS usually give the steadiest video. Action or wide stabilised modes crop more. Related: OIS, Video resolution and frame rate, Gyroscope and accelerometer.
PDAF (phase-detection autofocus): An autofocus method that uses special pixels on the sensor to work out the focus direction and distance quickly. Variants such as dual-pixel or all-pixel PDAF use more of the sensor and focus faster in low light. It is the main autofocus system on most phones today and is combined with other methods for accuracy. Related: Laser autofocus, Macro camera, LiDAR and depth sensors.
Laser autofocus: A small infrared sensor that measures the distance to a close subject to help the camera focus, mainly at short range. It helps in dim light where other methods struggle. It works at limited range and can be fooled by glass or very dark surfaces. Many phones now rely on depth sensors instead. Related: PDAF, LiDAR and depth sensors, Night mode.
Telephoto camera: A camera with a longer focal length that magnifies distant subjects and gives flattering portrait perspective. Typical telephotos give 2x to 3x optical zoom, with longer ones in periscope designs. A smaller sensor and a narrower aperture make them weaker in low light, so phones often switch to a cropped main camera at night. Related: Periscope telephoto, Optical zoom, Hybrid zoom, OIS.
Periscope telephoto: A zoom camera that folds the light path sideways inside the phone, allowing longer optical zoom (typically 3× to 10×) in a thin body. It is the practical way to get long zoom without a camera bump. Periscope lenses usually have a narrow aperture and a smaller sensor, so low-light zoom is limited. Check whether stabilisation is included, as it is essential at long range. Related: Telephoto camera, Optical zoom, Hybrid zoom, OIS.
Optical zoom: Magnification produced by a lens with a longer focal length, without cropping. Digital zoom crops and enlarges the image instead. On phones, optical zoom comes from dedicated telephoto lenses at fixed steps, such as 3x. Anything between steps uses cropping and processing. Optical zoom gives true detail, so it is the number to compare. Related: Hybrid zoom, Digital zoom, Telephoto camera, Periscope telephoto, Focal length.
Hybrid zoom: Zoom that combines a crop of a high-resolution sensor with computer processing, giving good quality at in-between zoom levels. Quality depends on the sensor megapixels and the software. It is better than plain digital zoom but weaker than true optical zoom. Marketing like 100x relies on digital zoom, which gives soft results. Related: Optical zoom, Digital zoom, Telephoto camera, Megapixels.
Digital zoom: Enlarging a cropped part of the image. Detail is not added, so photos get softer as zoom increases. Software sharpening can help a little but cannot recover real detail. Large digital zoom numbers on spec sheets rarely reflect usable image quality. Related: Optical zoom, Hybrid zoom, Telephoto camera.
Ultrawide camera: A camera with a very wide field of view, useful for landscapes, buildings and group shots in tight spaces. Ultrawide sensors are often smaller and have lower quality than the main camera, particularly at night and at the edges. Some can also be used for macro. Check sample photos rather than only megapixels. Related: Focal length, Macro camera, Camera sensor size.
Macro camera: A camera mode or dedicated lens for very close-up shots of small subjects. Dedicated 2MP macro cameras on budget phones add little value. A good autofocus ultrawide or telephoto that can focus close does the job better. Low-resolution macro lenses are often a spec-sheet filler. Related: Ultrawide camera, PDAF, Megapixels.
LiDAR and depth sensors (ToF): Sensors that measure distance by timing light pulses. They help with focusing and with depth effects such as portrait blur. They assist autofocus in dim conditions and some augmented reality uses. Most photo depth effects now come from software and multiple cameras, so a dedicated depth sensor is not a strong buying factor. Related: Laser autofocus, PDAF, Computational photography.
ISP (image signal processor): The part of the chipset that turns raw sensor data into a finished photo or video, handling noise, colour, focus and HDR. A stronger ISP allows faster shooting, better low-light processing and higher video modes. Two phones with the same sensor can produce very different photos because of the ISP and software tuning. Related: Computational photography, Chipset, HDR, Night mode.
Computational photography: Using software to combine several frames and apply machine learning to improve a photo, rather than relying on the lens and sensor alone. It drives HDR, night mode, portrait blur and zoom enhancements. The look is a matter of taste; some tunings over-sharpen or brighten shadows too much. Processing time also varies. Related: ISP, HDR, Night mode, NPU.
HDR (photos): High dynamic range: combining several exposures so both bright skies and dark shadows keep detail. It is on by default on most phones. Over-aggressive HDR can look flat or unnatural. Do not confuse it with HDR video or HDR display formats such as HDR10. Related: Computational photography, Night mode, HDR10, ISP.
Night mode: A mode that takes several frames over a second or more and merges them to produce a brighter, cleaner low-light photo. Stabilisation, sensor size and processing all affect results. It needs a steady hand or tripod for the best shot. Moving subjects can appear blurred. Related: OIS, Camera sensor size, Computational photography, Aperture.
DXOMARK scores: Scores from an independent lab that tests phone cameras, displays, audio and battery under a fixed protocol. Scores are useful as one more input, but the test protocol changes over time, so numbers from different versions are not directly comparable. Not every phone is tested. They measure what the lab measures, which may not match your taste in colour. Related: Computational photography, Delta E, Colour-tuning partnerships.
Colour-tuning partnerships (Pantone, ZEISS): Co-branding in which a colour or optics company is credited with validating or tuning a phone's camera or display colour. Depending on the maker, it can mean lens coatings, colour profile tuning or just a logo. There is no common standard for what the validation involves, so judge by sample photos and colour accuracy measurements. Related: DXOMARK scores, Delta E, Computational photography.
Selfie (front) camera: The camera facing you, used for selfies and video calls. Resolution is usually 8 to 50 megapixels, with some phones adding autofocus. Fixed-focus front cameras can be soft at arm's length, so autofocus is a useful extra. Beauty filters are often on by default and can over-smooth skin. Video call quality also depends on the software. Related: Punch-hole, notch and under-display camera, Megapixels, PDAF, Face unlock.
Video resolution and frame rate: Common video modes are 1080p, 4K and 8K at 24, 30 or 60 frames per second. Higher resolution gives more detail and bigger files. 4K at 30fps is a good default. 60fps gives smoother motion. Not all cameras on a phone support the same modes, and stabilisation can be limited at the highest settings. 8K is rarely worth the storage. Related: 10-bit video, EIS, OIS, Slow motion video, Storage.
10-bit video: Video recorded with 1024 levels per colour channel instead of 256, giving smoother gradients and more room for editing. It is usually paired with HDR formats such as HLG or Dolby Vision. Files are larger, and not every editor or TV handles them well. Casual users will see little difference in standard video. Related: Colour bit depth, Log video, Dolby Vision video recording, HDR10.
Log video: A flat, low-contrast video profile that keeps more detail in highlights and shadows, intended to be colour graded afterwards. Footage looks washed out until graded, so it is for editing workflows. It works best with 10-bit recording. For everyday clips, the standard profile is easier. Related: 10-bit video, Video resolution and frame rate, Dolby Vision video recording.
Dolby Vision video recording: Recording video in the Dolby Vision HDR format so playback on supported screens has a wide brightness range. Playback and sharing need a compatible screen or app; otherwise it may look flat or be converted. Files are larger. It is useful mainly if you watch on compatible devices. Related: Dolby Vision, 10-bit video, Log video.
Slow motion video: Recording at a high frame rate, such as 120 or 240fps, and playing it slower for a slow-motion effect. High frame rates are typically available only at lower resolutions and need plenty of light. Some very high figures are generated by interpolation in software. Check resolution at each frame rate. Related: Video resolution and frame rate, EIS, Storage.