A Photography and Technology Glossary for the Young and Old

4K                             In cinema, a horizontal image resolution of 4K e.g. 4096 x 2160 pixels.

Artificial Intelligence (A.I.) An attempt at human-level intelligence using a computer

Aperture Priority              You set the size of the aperture manually and the camera calculates the

                               shutter speed for optimum exposure.

APS-C                          Advanced Photo System type-C. A smaller image sensor than Full Frame.

APS Film                       Advanced Photo System (APS). A discontinued film format from 1996.

ASA Film Standard              American Standards Association

Aspect Ratio                   The ratio of width to height of an image e.g. 16:9, 3:2, 4:3, 1:1

Augmented Reality              The projection of a virtual world over the real one.

Bayer Filter                   An array of RGB filters on a grid with 2 greens for each red/blue to mimic the

                               human eye

Bluetooth                      A wireless communication standard for operating a wide range of devices

BMP                            Bitmap. An image file format for simple uncompressed device-independent

                               raster image data developed by Microsoft.

Bokeh                          The artistic effect of an out-of-focus partial image e.g. a portrait background

CCD Sensor                     Charge-Coupled Device. A chip that converts light to an analogue signal.

Chromatic Aberration           The failure of a lens system to focus all colours/wavelengths to the same

                               point. Often seen as purple fringes on brightness boundaries.

Circular Polariser             A special filter that can reduce the reflected light from water and sky glare

Cloud Storage                  The storage of data on remote servers connected to the Internet.

CMOS Sensor                    Complementary metal-oxide semiconductor. Converts light to digital data.

Colour Wheel                   A visualisation to show how colours match and clash with each other

Contrast Detection AF          Autofocus that detects maximum contrast in the image with focus hunting

Convolution Matrix             A grid of numbers (mask) that is moved across an image to process it

CPU                            Central Processing Unit. The chip that does all the calculations on general-purpose

                               hardware.

Crop Factor                    The ratio of the 35mm full frame sensor diagonal to that of a smaller sensor

DIN Film Standard              Deutsches Institut für Normung

Dioptre                        The reciprocal of the focal length of a lens in metres. Correction is

                               sometimes provided in viewfinders for those who wear glasses.

DoF                            Depth of Field. How much of your picture is sharp and in-focus.

Drone Photography              Aerial photography ( still & video ) taken from a remote-controlled device

DSLR                           Digital Single Lens Reflex camera. The reflex is from a swinging mirror.

EVF                            Electronic View Finder. The tiny television you look at to frame a picture.

Exposure Compensation          An ability to deliberately under or over expose an image to suit conditions

Fisheye Lens                   An extreme wide angle lens ( up to 180 degrees ) with large distortion

Focal-plane Shutter            A mechanical shutter with 2 shutter curtains positioned immediately in front

                               of the focal plane of the camera ( the image sensor ).

Full Frame                     A 35mm film standard ( 35mm wide strip ). Each frame is 36mm x 24mm.

Galileo                        The European version of GPS for navigation and positional data.

Gaussian Blur                  A mathematical equation for smoothly blurring an image e.g. to remove

                               noise

GIF                            Graphics Interchange Format. An image file format with 256 colours, lossless

                               compression and support for animation (GIF89a spec).

Global Shutter                 An electronic shutter which takes a snap of the scene using all of the pixels

                               all at once. Unlike a rolling shutter which reads from top to bottom. A global

                               shutter places huge demands on hardware.

GLONASS                        The Russian version of GPS for navigation and positional data.

GPS                            Global Positioning System for navigation and positional data by U.S. military

GPT                            Generative Pre-trained Transformer. Used to predict human-like text with A.I.

GPU                            Graphics Processing Unit. The chip dedicated to massively parallel calculations

                               for rendering graphics. Can also be used for neural networks.

HD (Full-HD) 1080p/720p        An image resolution of 1920 x 1080 pixels. Older 1280 x 720 standard.

HDR                            High Dynamic Range. An image with whiter-whites and blacker-blacks.

HEIF/HEIC                      High Efficiency Image File Format. An image file format popular with Apple. A

                               HEIC photo takes up about half the space of an equivalent quality JPEG file.

Hue (colour)                   The colour part of light. The place on the rainbow spectrum (wavelength).

Image Stabilisation            A mechanical or software counter-measure against camera shake

ISO Film Standard              International Organization for Standardization

Jpeg (jpg)                     Joint Photographic Experts Group. The most common form of lossy image

                               file compression for digital cameras. Typically 10:1 with negligible loss in

                               image quality but this can be adjusted.

LLM                            Large Language Models. Deep learning models that are pre-trained on huge

                               data sets

Magic Eraser                   The Google method of removing unwanted artefacts from your photo

Micro Four Thirds              A smaller image sensor than APS-C by about 30%

MILC                           Mirrorless Interchangeable-Lens Camera

Mixed Reality                  Similar to Augmented Reality. An interactive blend of real and virtual worlds.

Neural Network                 A mathematical construction simulating neurons in the human brain

OLED                           Organic Light-emitting Diode. An emissive electroluminescent layer made

                               from organic compounds

Orton Effect                   A dreamy, surreal filter effect using image blur and blending

Leaf Shutter                   A mechanical shutter with 1 or more blades covering a central aperture,

                               either inside or close behind the lens.

Lens Flare                     Light scattering in a lens system especially when pointing at a bright light

Light Field Camera             A camera that measures light rays ( angle and intensity ). This allows the

                               focus to be changed after the picture has been taken.

LZW                            Lempel–Ziv–Welch. A universal lossless data compression algorithm

                               comprising a self-generated dictionary, often used tom compress images.

Neural Network                 A simulation of the way the human brain works using inter-connected nodes

                               and weights. The network can be taught to recognise patterns in data.

Noise                          Unwanted texture/artefacts in a zoomed image due to too much gain. Usually

                               when taking pictures in very low light.

NPU                            Neural Processing Unit. A chip highly optimised to run neural networks for

                               A.I. purposes.

Panorama                       A picture with a high aspect ratio, at least 2:1 but could be a lot higher.

PASM                           Program, Aperture Priority (Av on Canon), Shutter Priority (Tv on Canon) and

                               Manual. The standard settings on a semi-professional camera dial.

Pentaprism                     The 5-sided glass at the top of SLR that bends light through 90° using 2

                               mirrored surfaces. It connects the viewfinder to the reflex mirror and lens.

Phase Detection AF             Rapid autofocus that compares light samples from different sides of the lens

Photo CD                       A Kodak standard from 1991 for storing digitally scanned photos on a

                               computer CD. About 100 photos up to 3072 x 2048 pixels each.

Pixel                          Picture Element. The smallest addressable dot in a raster image.

PNG                            Portable Network Graphics. An image file format from an improved non-

                               patented GIF format. Supports 32-bit RGBA and loss compression.

Program Mode                   An exposure mode where the camera determines the best aperture and

                               shutter speed settings for the light coming through the lens.

RAW                            The native digital output from the camera sensor with minimal processing

                               and no lossy compression. Specific to each camera manufacturer. May

                               contain a much wider range of colours than the final image in e.g. jpeg

                               format.

Resolution (sensor)            The maximum captured width and height of the digital image in pixels.

                               Sometimes the width x height in Megapixels.

Saturation (colour)            The ‘depth’ of a colour from intense ( fully saturated ) to grey ( unsaturated )

SD Card                        Secure Digital card. The most common storage media for cameras and

                               phones developed by the SD Association (SDA) for non-volatile, flash

                               memory cards.

Selfie                         A picture of yourself taken by yourself, popular on social media. For some

                               reason.

Sharpening                     The process of creating more texture/edge highlights in a soft image.

Shutter Priority               You set the shutter speed manually and the camera calculates the

                               size of the aperture for optimum exposure.

Sobel Filter                   Sobel–Feldman operator – see convolution matrix

Stitching                      The joining of images together to create a larger picture or more typically a

                               panorama. Software can be used to automate this task.

Telephoto Lens                 A lens with a long focal length ( e.g. 70mm to 200mm ) to magnify the

                               subject. Often used for wildlife photography.

TIFF                           Tagged Image File Format. An image file format popular with graphic artists.

Tilt-Shift                     An artistic out-of-focus effect caused by changing the orientation or position

                               of the lens with respect to the image sensor.

TOPS                           Tera operations per second. A benchmark figure for comparing neural network

                               chips for A.I. Minimum 40 TOPS for 'decent' local performance on a laptop is

                               the thinking in 2024.

TPU                            Tensor Processing Unit. A chip developed by Google specifically for accelerating

                               machine learning tasks.

Unsharp Mask                   An image processing technique which amplifies the difference between the

                               image and a blurred version of the same image ( the mask ). This produces a

                               sharper image.

UHD ( Ultra HD )               An image resolution of 3840 x 2160 pixels.

USB                            Universal Serial Bus. An industry-standard for cabled data exchange and

                               delivery of power. Many connectors and speeds, now at Type C.

Virtual Reality                The creation of a purely virtual world, often for gaming.

Vlogging                       Video Blogging. A popular form of communication for content creators.

You Tube                       The most popular video sharing platform from Google. Closely followed by

                               TikTok.

White Balance                  The colour temperature of your image which determines the purity of the

                               white colours. An unbalanced image could have a blue or orange tint, which

                               comes from your light source.

Wide-angle Lens                A lens with a short focal length ( e.g. 35mm or less ) to capture a wide field

                               of view. Often used to photograph buildings but care must be taken with

                               perspective distortion.

WiFi                           Wireless Fidelity. A wireless network protocol based on the IEEE 802.11

                               family of standards. Used to connect devices to the Internet.

ZIP                            An archive file format that supports lossless data compression