A to Z of Photography – Photography Glossary

1. Aperture: The opening in a camera lens that controls how much light passes through to the sensor, affecting exposure and depth of field.
2. Aspect Ratio: The proportional relationship between the width and height of an image (e.g., 4:3, 16:9). It affects composition and cropping.
3. Autofocus (AF): A camera system that automatically adjusts the lens to focus on a subject.
4. Ambient Light: The natural light in a scene without any added lighting, such as sunlight or indoor lighting.
5. AWB (Auto White Balance): A setting where the camera automatically adjusts the white balance to make colours appear natural based on lighting conditions.
6. AF-C (Continuous Autofocus): A camera setting that continuously adjusts focus on a moving subject.
7. Aliasing: Visual distortion that occurs when fine patterns or edges in an image become jagged or pixelated due to the limits of the sensor’s resolution.
8. AE Lock (Auto Exposure Lock): A function that locks the exposure settings while allowing you to recompose the shot.
9. The angle of View: The area of a scene captured by the lens, determined by the focal length. A wide-angle lens captures a broader scene than a telephoto lens.
10. Artifact: Unwanted distortions in an image, such as noise, halos, or pixelation, are often caused by compression or post-processing errors.
11. APS-C Sensor: A sensor size smaller than full-frame (typically found in DSLRs and mirrorless cameras), with a crop factor that affects focal length and depth of field.
12. ASA (American Standards Association): An older term used to measure film speed, now replaced by ISO.
13. Angle Finder: An accessory that attaches to a camera’s viewfinder, allowing the photographer to see through the lens at various angles, useful for low or high-angle shots.
14. Auto Bracketing: A feature where the camera automatically takes several shots at different exposures, focus points, or white balance settings.
15. Aerial Photography: The art of taking photographs from an elevated position, typically using drones, aeroplanes, or helicopters.

B

1. Bokeh: The aesthetic quality of the out-of-focus areas of an image, especially the background, often created by using a wide aperture.
2. Bracketing: A technique where multiple shots of the same scene are taken at different exposure settings to capture a broader range of details.
3. Bulb Mode: A camera setting that allows the shutter to remain open as long as the shutter button is pressed, used for long exposures.
4. Backlighting: When the primary light source is behind the subject, it often creates a silhouette or halo effect.
5. Burst Mode: A setting that allows multiple photos to be taken in quick succession by holding down the shutter button, useful for capturing fast action.
6. Blown Highlights: Overexposed areas in an image where details are lost due to excessive brightness, often appearing as pure white.
7. Barrel Distortion: A type of lens distortion that causes straight lines to curve outward, often seen with wide-angle lenses.
8. Buffer: The camera’s temporary memory that stores images while they are being written to the memory card, affects how quickly the camera can shoot continuously.
9. Black Point: The darkest part of an image where no detail is visible, used in editing to control contrast.
10. Bitmap: A digital image format made up of pixels, often large in file size, commonly used for high-quality images.
11. Bayonet Mount: A type of lens mount that allows lenses to attach to the camera body with a twist-and-lock motion.
12. Blooming: An image artefact where bright highlights spread into surrounding areas, reducing contrast.
13. Blurring: The effect created when an image or part of it appears soft or out of focus, either intentionally or accidentally.
14. Bounce Flash: A technique where flash is directed at a surface, such as a ceiling or wall, to create a softer, more diffused light.
15. Bridging Camera: A type of camera that fills the gap between compact cameras and DSLRs, offering more control and zoom capability without interchangeable lenses.

C

1. Chromatic Aberration: A lens defect where colours separate, creating coloured fringes around objects, usually noticeable at high-contrast edges.
2. Crop Factor: The ratio of a camera’s sensor size compared to a 35mm full-frame sensor, affecting the effective focal length of lenses.
3. Contrast: The difference between the light and dark areas in an image, which affects its depth and mood.
4. Clipping: When the highlights or shadows of an image are so bright or dark that detail is lost.
5. Continuous Lighting: Lighting that remains on, as opposed to a flash, is used in both video and still photography to create constant illumination.
6. Colour Cast: An unwanted tint in an image, often caused by incorrect white balance or lighting conditions.
7. Circular Polarizer: A filter that reduces reflections and glare from non-metallic surfaces, such as water and glass, while enhancing colour saturation.
8. Composition: The arrangement of elements within a photograph, guided by principles like the rule of thirds, leading lines, and symmetry.
9. Chiaroscuro: An artistic term referring to the use of strong contrasts between light and dark, often used to add drama and depth to portraits or still-life photography.
10. CPL (Circular Polarizer Filter): A filter that reduces reflections and enhances colours in landscape photography by filtering polarised light.
11. CMOS (Complementary Metal-Oxide Semiconductor): A type of image sensor used in digital cameras that converts light into electronic signals.
12. Colour Profile: A set of data that defines how colours are interpreted by devices like cameras, monitors, and printers.
13. Creative Commons License: A licensing system that allows photographers to share their work while retaining certain rights, often used in stock photography.
14. C-Stand: A versatile stand used in photography and video production to hold lights, modifiers, or reflectors.
15. Colour Grading: The process of altering and enhancing the colour of an image or video, often used in post-processing to achieve a specific mood or style.

D

1. Depth of Field (DoF): The range of distance in a photograph that appears sharp, determined by the aperture setting, focal length, and distance from the subject.
2. Diffuser: A device that softens and scatters light to create a softer, less harsh lighting effect, commonly used with flashes or continuous lights.
3. Digital Zoom: A camera function that crops into the centre of an image and enlarges it, often resulting in a loss of image quality.
4. Dynamic Range: The range of tonal values between the darkest shadows and the brightest highlights that a camera can capture.
5. Dodging: A darkroom or post-processing technique used to lighten specific areas of an image to enhance detail.
6. Double Exposure: A technique where two images are exposed onto the same frame, often used creatively to blend two scenes or subjects.
7. Diopter: An adjustment on a camera’s viewfinder that allows photographers to fine-tune the focus to match their eyesight.
8. DSLR (Digital Single-Lens Reflex): A type of digital camera that uses a mirror mechanism to direct light from the lens to an optical viewfinder.
9. Distortion: An optical imperfection in a lens that causes straight lines to appear curved, often occurring with wide-angle lenses.
10. Drive Mode: A camera setting that determines how the shutter behaves, such as single-shot, continuous shooting, or self-timer.
11. DPI (Dots Per Inch): A measure of image resolution in printing, indicating how many dots of ink are placed in a linear inch. The higher the DPI, the better the print quality.
12. Digital Negative (DNG): An open-source RAW file format created by Adobe, used to archive and share RAW image data.
13. Desaturation: The process of reducing the intensity of colours in an image, often used to create a muted or black-and-white effect.
14. Direct Light: Light that travels straight from the source to the subject, creating hard shadows and high contrast.
15. Diffraction: A phenomenon that occurs when light bends around the edges of an object, causing a loss of sharpness at very small apertures.

E

1. Exposure: The amount of light that hits the camera sensor, determined by the combination of aperture, shutter speed, and ISO.
2. EV (Exposure Value): A number representing the combination of aperture and shutter speed that determines exposure. EVs can be adjusted to make an image brighter or darker.
3. Exif Data (Exchangeable Image File Format): Metadata stored in image files that includes information about camera settings, date, time, and sometimes GPS location.
4. Exposure Compensation: A camera setting that allows you to adjust the exposure in automatic or semi-automatic modes, typically by ±3 stops.
5. Eye Autofocus (Eye AF): A feature in modern cameras that automatically detects and focuses on the subject’s eye, commonly used in portrait photography.
6. Edge Light: A light source positioned to illuminate the edges of a subject, often creating a rim or halo effect that separates the subject from the background.
7. E-TTL (Evaluative Through-The-Lens): A flash metering system that uses the camera’s sensor to calculate the correct flash exposure.
8. Eclipse Filter: A specialised solar filter used to safely photograph solar eclipses, blocking out most of the sun’s light to prevent damage to the camera sensor and eyes.
9. Environmental Portrait: A portrait where the subject is photographed in their natural surroundings or workplace, telling a story about who they are.
10. Exposure Bracketing: A technique where multiple shots are taken at different exposures, usually to combine them into a single image with a higher dynamic range.
11. Eccentricity: A lens defect that causes parts of an image to be out of focus due to imperfections in the lens construction.
12. Eyedropper Tool: A tool in photo editing software used to select and match specific colours from an image for colour correction or retouching.
13. EVF (Electronic Viewfinder): A small digital display showing a live preview of the captured scene, commonly found in mirrorless cameras.
14. Extension Tubes: Hollow tubes placed between the camera body and lens to allow for closer focusing distances, commonly used in macro photography.
15. Exposure Latitude: The range of exposure a camera can handle while still retaining detail in highlights and shadows, which is important for scenes with high contrast.

F

1. F-Stop: A number that represents the size of the aperture opening in a lens. A lower f-stop (e.g., f/1.8) means a larger aperture and more light, while a higher f-stop (e.g., f/16) means a smaller aperture and less light.
2. Fill Light: A secondary light source used to reduce shadows created by the primary (key) light, balancing the overall exposure.
3. Flash Sync Speed: The fastest shutter speed at which the camera can synchronise with an external flash, typically around 1/200 or 1/250 of a second.
4. Focal Length: The distance between the lens and the camera sensor when the subject is in focus, measured in millimetres. It affects the angle of view and magnification.
5. Frame Rate: The number of frames a camera captures per second, often referenced in video or burst shooting, typically measured in FPS (frames per second).
6. Full-Frame Sensor: A camera sensor that is equivalent in size to a 35mm film frame (36x24mm), offering a wider field of view and better low-light performance compared to crop sensors.
7. Focus Peaking: A camera feature that highlights the edges of the subject that are in focus, making it easier to achieve sharp focus, especially in manual mode.
8. Foreground: The part of a scene or image that is closest to the camera, often used to add depth and interest to the composition.
9. Fresnel Lens: A type of lens used in some lighting setups that focuses light into a beam, commonly used in theatre and studio lighting.
10. Filter: A device attached to the front of a lens to alter the light entering the camera, such as polarisers, ND filters, and UV filters.
11. Flash Duration: The length of time a flash emits light, typically measured in milliseconds. Shorter durations are useful for freezing fast-moving subjects.
12. Firmware: The software that runs inside the camera or other photographic equipment, often updated to add new features or fix bugs.
13. Focus Breathing: A phenomenon where the framing of an image changes slightly when adjusting focus, most noticeable with some zoom lenses.
14. Fringing: Color distortions or aberrations that appear along high-contrast edges in an image, typically caused by lens imperfections.
15. Flat Lighting: A lighting style where light is evenly distributed across the subject, reducing shadows and creating a soft, low-contrast look.

G

1. Golden Hour: The period shortly after sunrise or before sunset when the sunlight is soft, warm, and diffused, often considered the best time for outdoor photography.
2. She graduated with ND Filter, A neutral density filter that transitions from dark to clear, used to balance the exposure between the sky and the foreground in landscape photography.
3. Grain: The visual noise or texture seen in an image, especially in film photography or digital images shot at high ISO settings.
4. Gobo: A device or material used to block or shape light in studio photography, often to create patterns or prevent light from spilling onto certain areas.
5. Guide Number: A measurement of a flash’s power, indicating how far its light can reach. Higher guide numbers indicate more powerful flashes.
6. Group Shot: A photograph that features multiple people, often requiring careful posing, lighting, and composition to ensure everyone is visible and properly lit.
7. Gamut: The range of colours that can be represented in an image, print, or display. A wide gamut can display more colours accurately.
8. Gels: Colored transparent sheets placed in front of lights or flashes to alter the colour temperature or add creative effects to the lighting.
9. Grey Card: A neutral-coloured card used to help set white balance and exposure by providing a reference point for the middle grey in the scene.
10. GND Filter (Graduated Neutral Density Filter): A filter that darkens part of the image (usually the sky) while leaving the rest (usually the foreground) unaffected, commonly used in landscape photography.
11. Gamma: A term used to describe the non-linear relationship between an image’s brightness and the actual scene. Adjusting gamma can control contrast and brightness in mid-tones.
12. Gimbal: A stabilising device used to keep a camera steady during movement, commonly used in video production for smooth, cinematic shots.
13. Geotagging: The process of adding GPS data to an image’s metadata, recording the location where the photo was taken.
14. Ghosting: A visual artefact that occurs when light reflects off lens elements, often appearing as faint, repeated images or streaks of light, especially when shooting into the sun.
15. Gutter: The space between two facing pages in a printed publication, such as a photo book or magazine, which can affect how a photo is viewed when spread across both pages.

H

1. HDR (High Dynamic Range): A technique that involves capturing multiple exposures of the same scene and merging them to create an image with a greater range of tonal detail in the highlights and shadows.
2. Histogram: A graphical representation of the tonal values in an image, showing the distribution of shadows, midtones, and highlights.
3. Hot Shoe: A mounting point on the top of a camera used to attach external devices, such as flashes, microphones, or wireless triggers.
4. Hyperfocal Distance: The distance at which everything from half that distance to infinity appears in sharp focus, maximising the depth of field in landscape photography.
5. Highlight Clipping: Overexposed areas of an image where detail is lost and appears as pure white.
6. Haze Filter: A filter used to reduce the effects of atmospheric haze or UV light in outdoor photography, improving clarity and contrast.
7. HSS (High-Speed Sync): A flash technique that allows you to use a flash at shutter speeds faster than the camera’s native sync speed, useful for balancing bright ambient light with flash.
8. Hard Light: Light that creates sharp, defined shadows and high contrast, often produced by a small, direct light source such as the sun or a bare flash.
9. Halftone: A technique used in printing where continuous tone images are converted into a series of dots of varying sizes to create the illusion of gradients.
10. Handheld Meter: A light meter that is separate from the camera and used to measure ambient or flashlight for precise exposure settings.
11. Hue: The colour or shade of light, such as red, blue, or green, as opposed to its saturation or brightness.
12. Histogram Blinking: A camera feature that highlights overexposed areas of an image by flashing them on the display, helping photographers avoid blown highlights.
13. Hybrid Camera: A camera that is designed for both still photography and video, offering features tailored to both formats.
14. Half Press: The act of pressing the camera’s shutter button halfway down to lock focus and exposure before fully pressing it to take a picture.
15. Halation: A photographic phenomenon where light spreads beyond its boundaries, creating a glow or halo effect, often seen in older film stocks or certain lighting conditions.

I

1. ISO: A camera setting that controls the sensor’s sensitivity to light. A lower ISO (100-200) is used in bright conditions, while a higher ISO (1600+) is used in low light but can introduce noise.
2. Image Stabilization (IS): Technology in cameras or lenses that reduces blur caused by camera shake, enabling sharper images at slower shutter speeds.
3. Incident Light: Light that directly falls on a subject, as opposed to light that reflects off other surfaces.
4. Intervalometer: A device or camera feature that automatically takes photos at set intervals, often used for time-lapse photography.
5. ICC Profile: A file format that describes the colour characteristics of a device (monitor, camera, printer) and helps maintain colour accuracy across different devices.
6. Image Compression: The process of reducing an image file’s size, either through lossy (e.g., JPEG) or lossless (e.g., TIFF) methods, often affecting quality.
7. Infrared Photography: A technique that captures light not visible to the human eye, usually using specialised filters or sensors, creating surreal effects.
8. Image Noise: Unwanted grain or distortion in an image, often introduced by high ISO settings or low light conditions.
9. Inkjet Printing: A popular printing method for photographs where tiny droplets of ink are sprayed onto paper to produce an image.
10. Interchangeable Lens: A lens that can be removed from the camera body and replaced with another lens, giving photographers greater flexibility.
11. Image Circle: The circular area of light projected by a lens onto the camera sensor or film, affecting how much of the image is recorded by the sensor.
12. Internal Focusing: A lens design where focusing occurs inside the lens barrel, meaning the physical length of the lens doesn’t change during focus.
13. IR Filter (Infrared Filter): A filter that blocks visible light but allows infrared light to pass, often used for creative or scientific infrared photography.
14. Inverse Square Law: A law that explains how light intensity decreases as the distance from the light source increases; useful for controlling lighting in photography.
15. Interpolation: A method of increasing the size or resolution of an image by adding pixels, often leading to a loss in quality if overused.

J

1. JPEG (Joint Photographic Experts Group): A widely used image file format that compresses image data to save storage space, typically leading to some loss of quality.
2. Jaggies: A term used to describe the visible pixelation or stair-stepping that occurs when diagonal lines or curves are poorly rendered in low-resolution images.
3. Juxtaposition: Placing contrasting subjects or elements together in a photograph to create visual interest, often used in street or conceptual photography.
4. JPEG Artifact: Visual distortions, such as blurring or pixelation, caused by excessive compression in JPEG files.
5. Jump Cut: In video or stop-motion photography, a cut where the subject appears to jump or move suddenly due to missing frames or images is often used stylistically.
6. Joule: A unit of measurement for energy commonly used to describe the power output of a studio flash unit.
7. Jointing: A technique in panoramic photography where multiple images are seamlessly combined to create one large image.
8. Jitter: Refers to small, irregular movements in video or time-lapse photography that can cause the image to appear shaky or uneven.
9. Judder: A slight, jerky motion in video playback, often caused by inconsistencies in frame rate or shutter speed.
10. JPEG 2000: An advanced version of the JPEG format that supports higher compression without noticeable loss of quality, though it is not widely used.
11. Just-in-Time Editing: A workflow strategy where editing is done quickly and efficiently at the last possible moment, often in news or event photography.
12. Judging Panel: In photography competitions, this refers to a group of experts who review and score submitted images based on various criteria.
13. JND (Just Noticeable Difference): The smallest change in a photographic element (such as brightness or contrast) that is noticeable to the human eye.
14. JPEG XS: A new image compression standard aimed at offering low-latency, visually lossless compression intended for real-time applications like VR and streaming.
15. Joint Photographic Experts Group (JPEG Committee): The organisation responsible for developing the JPEG standard, which revolutionised digital image compression.

K

1. Kelvin (K): The unit of measurement for colour temperature in photography. Lower values (2000K-4000K) produce warm, yellow light, while higher values (5000K-7000K) produce cool, blue light.
2. Key Light: The primary light source in a photography setup, usually the strongest light that defines the shape and dimension of the subject.
3. Kicker Light: A secondary light placed behind or to the side of a subject to create a highlight, often used to separate the subject from the background.
4. Kodachrome: A brand of colour reversal film introduced by Kodak, known for its rich colours and sharpness. It was widely used in the 20th century but discontinued in 2009.
5. Kilobyte (KB): A unit of digital data equivalent to 1024 bytes, commonly used to describe the size of small image files or metadata.
6. Keystone Correction: A method used to correct the perspective distortion in architectural photography when the camera is not level, making parallel lines appear straight.
7. Kodak Moments: A popular term coined by Kodak to describe emotionally powerful or memorable moments captured in photographs.
8. Kirlian Photography: A photographic technique that captures the electrical discharge of objects, often associated with paranormal or scientific photography.
9. K-Index: A measurement used in astrophotography to describe geomagnetic activity and its effect on auroras, helping photographers plan shoots of the Northern or Southern Lights.
10. Kelvin Shift: An intentional or accidental shift in the colour temperature of a light source, often corrected through white balance adjustments.
11. Knockout: A term used in photo editing where a subject is separated from its background, often for compositing purposes.
12. Keyframe: In video or animation, keyframes mark specific points where major changes occur, such as transitions, lighting shifts, or subject movement.
13. Kirlian Effect: The visual effect in Kirlian photography where glowing edges surround a subject due to an electrical discharge.
14. Knot in Composition: A visual point in a photograph where multiple elements converge, often used to draw attention to a specific part of the image.
15. Kickback Lighting: A lighting technique where light bounces off a surface, such as a reflector, to fill in shadows on the subject.

L

1. Lens: The optical component of a camera that focuses light onto the sensor. Lenses vary in focal length, aperture, and optical quality, affecting the image’s sharpness, distortion, and perspective.
2. Low-Key Lighting: A lighting style that uses strong contrast between light and dark areas, creating a moody, dramatic effect with deep shadows.
3. Leading Lines: Compositional elements that guide the viewer’s eye through the photograph, often toward the main subject, such as roads, rivers, or architectural lines.
4. Long Exposure: A technique where the camera’s shutter is left open for an extended period to capture motion, such as light trails, star trails, or smooth water.
5. Lens Flare: Bright spots, rings, or streaks of light that occur when the lens is pointed toward a bright light source, such as the sun. It can be an unwanted effect or used creatively.
6. Light Meter: A device or camera tool used to measure light intensity in a scene, helping photographers determine the correct exposure settings.
7. Luminosity: The brightness of an image, often referring to the grayscale values in a photograph, even in colour images.
8. Latitude: The degree of exposure variation a film or digital sensor can handle before losing detail in the highlights or shadows.
9. Lens Hood: An accessory attached to the front of a lens to block stray light and reduce lens flare, often used in outdoor photography.
10. Low-Pass Filter: An optical filter placed over a camera sensor to reduce aliasing and moiré patterns, though it can slightly reduce sharpness.
11. Lith Print: A darkroom printing technique that produces high-contrast, gritty images with unique colour tones, often used for artistic photography.
12. Light Painting: A photographic technique where light is manually moved in a dark scene during a long exposure, creating streaks, shapes, or patterns of light.
13. LUT (Look-Up Table): A file used in video and photo editing that applies specific colour grading to an image, changing the overall look or mood.
14. Light Falloff: The gradual reduction of light intensity as it moves away from the source, following the inverse square law.
15. Live View: A camera mode where the image from the sensor is displayed on the LCD screen instead of through the viewfinder, useful for composing shots, especially in difficult angles.

M

1. Manual Mode: A camera mode that allows the photographer to control all aspects of exposure, including shutter speed, aperture, and ISO, for full creative control.
2. Macro Photography: A type of photography that captures extreme close-up images of small subjects, such as insects, flowers, or textures, often with a macro lens.
3. Metadata: Data embedded in an image file that contains information about how the image was captured, such as camera settings, date, time, and sometimes GPS coordinates.
4. Monochrome: An image consisting of varying shades of one colour, typically black and white, but can refer to any single colour tone.
5. Metering Mode: A camera setting that determines how the light meter calculates exposure, with common modes including spot, centre-weighted, and matrix metering.
6. Medium Format: A camera format larger than full-frame (35mm) that provides higher resolution and dynamic range, commonly used in commercial and fine-art photography.
7. Moiré: A visual distortion that occurs when fine patterns in an image interfere with the pixel grid of the sensor, creating unwanted, wavy lines.
8. Mirrorless Camera: A camera that lacks the mirror and optical viewfinder found in DSLRs, using an electronic viewfinder or LCD screen instead. Typically, it is more compact.
9. Motion Blur: The streaking or blurring of moving subjects in an image, typically caused by a slower shutter speed.
10. Multiple Exposure: A creative technique where two or more exposures are combined into a single image, either in-camera or during post-processing.
11. Midtones: The middle range of brightness in an image, between the darkest shadows and the brightest highlights, often where the most detail is found.
12. Model Release: A legal document signed by a model or subject granting the photographer permission to use their likeness in photographs for commercial purposes.
13. Monopod: A one-legged support used to stabilise a camera, providing more mobility than a tripod while reducing camera shake at slower shutter speeds.
14. Micro Four Thirds (MFT): A camera sensor format smaller than APS-C, offering a crop factor of 2x, commonly found in mirrorless cameras for a balance between size and image quality.
15. Matrix Metering: A metering mode that divides the frame into multiple zones, analysing each area to determine the best exposure, often the default setting in modern cameras.

N

1. ND Filter (Neutral Density Filter): A filter that reduces the amount of light entering the lens, allowing for longer exposures or wider apertures in bright conditions.
2. Noise: The grain or speckling that appears in an image, especially at high ISO settings or in long exposures, reducing image quality.
3. Nodal Point: The point inside a lens where light converges before being projected onto the sensor. In panoramic photography, rotating around this point avoids parallax errors.
4. Negative Space: The empty or unoccupied area around the subject in an image, often used to create balance, simplicity, or emphasise the main subject.
5. Nikon: A well-known manufacturer of cameras and photography equipment, particularly popular among professional and enthusiast photographers.
6. Non-Destructive Editing: An editing technique where changes to an image are made without altering the original file, allowing for reversibility, commonly used in software like Photoshop and Lightroom.
7. Noise Reduction: A process used in digital photography to reduce the amount of noise in an image, often applied in-camera or during post-processing.
8. Neutral Color: Colors like white, black, and grey that have no hue and do not affect the colour balance of an image.
9. Negative: In film photography, the image is recorded on photographic film where the lightest areas of the photo appear darkest, and the darkest areas appear lightest. These are then reversed during printing.
10. Nifty Fifty: A popular term for a 50mm prime lens known for its versatility, sharpness, and ability to create natural-looking images.
11. Night Photography: A genre of photography that focuses on capturing images in low-light or nighttime conditions, often requiring long exposures and a tripod.
12. Nano Coating: An advanced type of lens coating that reduces reflections and flare, improving contrast and sharpness in high-end lenses.
13. Near Infrared: A spectrum of light that is just beyond the visible range, used in infrared photography to capture surreal or scientific images.
14. Neutral Tones: Shades of white, grey, and black that lack colour saturation, often used in portrait and landscape photography for a natural look.
15. Noise Floor: The baseline level of noise in an image or signal, often influenced by the camera’s sensor technology and environmental factors.

O

1. Optical Zoom: A zoom method that uses the physical movement of a lens’s elements to magnify the subject without losing image quality, unlike digital zoom.
2. Overexposure: When too much light reaches the camera sensor, resulting in a photograph that is too bright and loses detail in the highlights.
3. Optical Viewfinder: A viewfinder that allows photographers to see directly through the lens via a mirror and prism system, commonly found in DSLRs.
4. Off-Camera Flash: A technique where the flash is detached from the camera and positioned separately, allowing for more creative control over lighting.
5. Optical Image Stabilization (OIS): A technology built into some lenses or cameras that compensates for camera shake, resulting in sharper images at slower shutter speeds.
6. Overhead Lighting: A lighting setup where the primary light source is placed directly above the subject, often creating dramatic shadows and highlights.
7. Optical Low-Pass Filter: A filter used in front of a camera sensor to reduce moiré patterns and aliasing, though it can slightly reduce sharpness.
8. Overlay: A compositional tool used in photo editing where a secondary image or texture is placed over the main image, blending the two for creative effects.
9. Out of Focus: Refers to areas of an image that are not sharp, often intentionally used for artistic purposes, such as bokeh, or due to incorrect focus.
10. Overexposed Highlights: Bright areas of an image where detail has been lost due to excessive exposure, often appearing as pure white.
11. Optical Aberration: A defect in a lens that causes distortion or blurriness, such as chromatic aberration or spherical aberration.
12. Overlay Mode: A blending mode in editing software that combines two layers, enhancing contrast by darkening shadows and brightening highlights.
13. Orton Effect: A post-processing technique that blends sharp and blurred versions of the same image to create a dreamy, glowing effect, often used in landscape photography.
14. One-Light Setup: A minimalist lighting setup that uses a single light source to illuminate the subject, often combined with reflectors or natural light for additional fill.
15. Outtakes: Images or shots that were not selected or used in the final set, often from photo shoots or video recordings.

P

1. Panning: A technique where the camera follows a moving subject during an exposure, resulting in a sharp subject against a blurred background, creating a sense of motion.
2. Prime Lens: A lens with a fixed focal length (e.g., 35mm or 50mm) that generally offers better sharpness, wider apertures, and superior image quality compared to zoom lenses.
3. Post-processing: The editing and enhancement of photographs after they have been captured, using software like Photoshop, Lightroom, or Capture One.
4. Perspective: The sense of depth and spatial relationships between objects in a photo, influenced by lens focal length and the camera’s position relative to the subject.
5. Panorama: A wide-angle view of a scene, either captured with a wide-angle lens or by stitching multiple images together in post-processing.
6. Pixel: The smallest unit of a digital image, typically measured in megapixels (MP). More pixels usually result in higher image resolution and detail.
7. Parallax: A shift in the relative positions of objects when viewed from different angles, particularly relevant in panoramic photography when objects at different distances move relative to each other.
8. Polarising Filter: A filter used to reduce reflections and glare from non-metallic surfaces, enhance contrast, and deepen sky colours in landscape photography.
9. Picture Style: Pre-set image processing settings in cameras that adjust the colour, contrast, sharpness, and other characteristics of the final image.
10. Pixelation: The blocky appearance of an image when it’s viewed at too low a resolution for its size, often seen when an image is enlarged too much.
11. Portrait Mode: A camera setting or smartphone feature that focuses on the subject’s face, often blurring the background to create a shallow depth-of-field effect.
12. Pincushion Distortion: A type of lens distortion where straight lines bow inward, common in telephoto lenses or when shooting at the extreme edges of a zoom range.
13. PPI (Pixels Per Inch): A measurement of image resolution on a screen, determining how many pixels are displayed within a linear inch. A higher PPI means more detailed images.
14. Program Mode (P): A semi-automatic camera mode where the camera sets both aperture and shutter speed, but the photographer retains control over other settings like ISO and focus.
15. Perspective Distortion: A distortion effect caused by the angle of view, particularly in wide-angle lenses, making objects close to the lens appear larger than those further away.

Q

1. Quick Release Plate: A small plate that attaches to the bottom of a camera, allowing it to quickly mount or dismount from a tripod head.
2. Quadcopter: A type of drone with four rotors commonly used for aerial photography and videography.
3. Quantum Efficiency: The effectiveness with which a camera sensor converts light into an electrical signal, affecting low-light performance and noise levels.
4. QLED (Quantum Dot Light Emitting Diode): A type of display technology used in high-end monitors, providing better colour accuracy and brightness useful for photo editing.
5. Quality of Light: Refers to the characteristics of light, such as hardness, softness, direction, and colour, which affect the appearance of the subject in the photo.
6. Quick Mask: A feature in Photoshop and other editing programs that allows precise selections to be made using a brush tool, often for masking or refining specific areas.
7. Quad Tone: A printing process that uses four different inks to create an image with a broad tonal range, often used in high-quality black-and-white prints.
8. Quick Fix: A term in photo editing for a fast, automatic adjustment to brightness, contrast, or colour, though it may not always be the best method for professional results.
9. Quantum Meter: A light meter specifically designed to measure the intensity of light from flash units, helping photographers balance ambient and artificial light.
10. Quiet Shutter: A camera feature that reduces the noise produced by the mechanical shutter, useful for discreet shooting in quiet environments like weddings or performances.
11. Quad Tone Printing: A method of printing images with four tones or colours, typically used to achieve rich, detailed black-and-white prints with depth and texture.
12. Quenching: A flash technique that stops the flash burst prematurely to control the amount of light emitted, often used in TTL flash systems.
13. Quantum Flash: A brand of powerful flash units often used in studio photography, known for their high output and versatile modifiers.
14. Quick Time Lapse: A method of creating a time-lapse sequence where fewer frames are captured over a shorter period, resulting in faster motion in the final video.
15. Quadtone Image: An image that uses four different inks or tones to achieve a wider dynamic range and smoother gradations, particularly in monochrome printing.

R

1. RAW File: A file format that captures all the data recorded by the camera sensor, providing greater flexibility for editing than JPEG or TIFF.
2. Rule of Thirds: A compositional guideline that divides an image into a 3×3 grid, suggesting that placing the subject along one of the grid lines or intersections creates a more balanced and engaging image.
3. Reflector: A surface used to bounce light onto a subject, often used in portrait photography to fill in shadows and create softer lighting.
4. Resolution: The amount of detail an image holds, typically measured in pixels or megapixels. Higher resolution allows for larger prints and more detailed images.
5. Red-Eye Reduction: A camera feature that uses a pre-flash or adjusts the settings to minimise the red-eye effect, where the subject’s eyes appear red due to the reflection of the flash off the retina.
6. Rim Light: A lighting technique where light is placed behind the subject, creating a halo or rim of light around the edges, separating the subject from the background.
7. Recomposition: The act of adjusting the framing of a shot after locking focus, often used in portraiture to place the subject according to compositional rules.
8. Reflective Light Meter: A light meter that measures the light bouncing off the subject and into the camera, as opposed to incident light meters that measure the light falling on the subject.
9. Rangefinder: A type of camera that uses a separate viewfinder system for focusing, as opposed to SLRs that use a through-the-lens viewfinder.
10. Remote Trigger: A device that allows a camera or flash to be triggered wirelessly, often used in studio photography or when the camera is set up in difficult-to-reach locations.
11. Reciprocity: The relationship between aperture, shutter speed, and ISO in determining exposure. Adjusting one element requires compensating with another to maintain the same exposure level.
12. RAW+JPEG: A shooting mode where the camera simultaneously captures both a RAW file for post-processing flexibility and a JPEG for immediate use or sharing.
13. Rear Curtain Sync: A flash setting that fires the flash at the end of the exposure, often used to create motion trails behind moving subjects while freezing them at the end of the motion.
14. Range of Focus: The distance between the nearest and farthest objects that are acceptably sharp in an image, also known as depth of field.
15. Red Filter: A filter used in black-and-white photography to darken skies and increase contrast, making clouds stand out more dramatically.

S

1. Shutter Speed: The length of time the camera’s sensor is exposed to light, measured in fractions of a second (e.g., 1/1000s). Faster shutter speeds freeze motion, while slower speeds create motion blur.
2. Softbox: A lighting modifier that diffuses light from a flash or continuous light source, creating soft, even illumination with minimal shadows, commonly used in portrait photography.
3. Spot Metering: A metering mode where the camera measures light from a small, specific area of the frame, often used for accurate exposure on a subject in high-contrast scenes.
4. Sharpness: The clarity and detail of an image, determined by the lens, focus accuracy, and post-processing. Sharpness can be affected by factors like shutter speed and camera movement.
5. Saturation: The intensity or vividness of colours in an image. Increasing saturation makes colours more vibrant while decreasing it can result in a more muted or monochromatic effect.
6. Sensor Size: The physical dimensions of a camera’s sensor, which influences image quality, depth of field, and field of view. Larger sensors generally offer better performance in low light and greater dynamic range.
7. Sync Speed: The fastest shutter speed at which a camera can synchronise with a flash, typically around 1/200 or 1/250 of a second. Going faster without special flash settings can result in incomplete flash exposure.
8. Shutter Lag: The delay between pressing the shutter button and the camera taking the photo, particularly common in older digital cameras or slower autofocus systems.
9. Side lighting: A lighting technique where the light source is positioned to the side of the subject, creating shadows that add depth and texture to the image.
10. Selective Focus: A technique where only a specific part of the image is in sharp focus while the rest is blurred, often used to draw attention to a particular subject.
11. Soft Focus: A photographic effect that intentionally creates a slightly blurred image, often used for portraits to create a dreamy or romantic look.
12. Starburst Effect: A phenomenon that occurs when shooting with a small aperture (e.g., f/16) and a bright point of light, such as the sun or streetlights, creating a star-shaped flare in the image.
13. Stop Down: The act of reducing the size of the aperture (e.g., going from f/2.8 to f/5.6), allowing less light to reach the sensor and increasing the depth of field.
14. Split Lighting: A portrait lighting setup where half of the subject’s face is illuminated, and the other half is in shadow, creating a dramatic and high-contrast effect.
15. Studio Strobe: A powerful, often large, flash unit used in studio photography that produces a brief burst of light, allowing for precise control over lighting in controlled environments.

T

1. Telephoto Lens: A lens with a long focal length (e.g., 100mm to 600mm), allowing photographers to zoom in on distant subjects commonly used in sports, wildlife, and portrait photography.
2. Time-Lapse: A photographic technique that involves taking a series of photos at set intervals and combining them into a video, creating the illusion of sped-up movements, such as clouds or city traffic.
3. Tonal Range: The range of tones between the darkest shadows and the brightest highlights in an image. A wide tonal range includes deep blacks and bright whites, while a narrow range may result in more muted tones.
4. Tripod: A three-legged stand used to stabilise the camera, particularly useful for long exposures, low-light photography, or precise framing.
5. Tilt-Shift Lens: A specialised lens that allows for tilt and shift movements, enabling photographers to control perspective and depth of field in ways that are not possible with standard lenses, often used in architectural photography.
6. Tethered Shooting: A workflow where the camera is connected to a computer or tablet, allowing images to be viewed and edited in real-time as they are captured.
7. Tungsten Light: A type of artificial lighting that produces a warm, yellow-orange light, commonly used in film and photography. Tungsten light has a colour temperature of around 3200K.
8. Time Code: A sequence of numbers assigned to individual frames in a video, making it easier to sync audio and video or reference specific points in editing.
9. Texture: The visual quality of the surface of a subject, often emphasised through lighting and focus, creating a tactile appearance in photographs.
10. Test Shot: A preliminary photo taken to check lighting, exposure, and composition before taking the final shot, often used in studio or controlled settings.
11. Tonality: The overall brightness, contrast, and colour of an image affect the mood and feel of the photograph.
12. TTL (Through the Lens): A metering system in cameras and flashes that measures the light coming through the lens to determine the correct exposure or flash output.
13. T-Stop: A measure of a lens’s actual light transmission, factoring in how much light is lost as it passes through the lens elements. Unlike f-stop, which measures aperture size, T-stops provide a more accurate representation of light reaching the sensor.
14. Tracking AF: A type of autofocus mode where the camera continuously adjusts focus to follow a moving subject, often used in sports or wildlife photography.
15. Tone Mapping: A process used in HDR photography to adjust the tonal range of an image, compressing the wide dynamic range into a viewable format that retains details in both highlights and shadows.

U

1. Underexposure: When too little light reaches the camera sensor, resulting in a photograph that is too dark and lacks detail in the shadows.
2. UV Filter: A clear filter placed in front of a camera lens to block ultraviolet light, often used to protect the lens from scratches or dust.
3. Upsampling: The process of increasing the resolution of an image by adding extra pixels, often resulting in a loss of sharpness and quality if not done carefully.
4. Urban Exploration (Urbex): A genre of photography that involves exploring and photographing abandoned or derelict buildings and locations, often capturing the decay and history of urban spaces.
5. Ultra-Wide Angle Lens: A lens with an extremely short focal length (e.g., 10-20mm), providing a wide field of view, often used in landscape, architecture, and interior photography.
6. Unsharp Mask: A post-processing technique used to sharpen an image by increasing the contrast along the edges of objects, making them appear more defined.
7. Underexposed Highlights: The areas of an image that are too dark due to underexposure, often appearing without detail or clarity in the shadows.
8. Umbrella Light: A type of lighting modifier that diffuses light from a flash or continuous light source, providing soft and even illumination, commonly used in portrait photography.
9. Ultra-Fast Lens: A lens with a very wide maximum aperture (e.g., f/1.2 or f/1.4), allowing for greater control over depth of field and better performance in low light.
10. Uncompressed RAW: A type of RAW file format that retains all the original data from the camera sensor without any compression, resulting in larger file sizes but higher image quality.
11. Unity of Composition: A compositional principle where all elements in a photograph work together harmoniously to create a balanced and cohesive image.
12. Underexposed Shadows: Shadows in a photograph that are too dark due to insufficient exposure, often resulting in loss of detail.
13. Up-Light: A lighting technique where light is directed upward onto the subject, often used for dramatic effects or to emphasise specific features in portrait photography.
14. Unicolor Photography: A style of photography where a single colour dominates the image, either through lighting, editing, or the subject itself, creating a unified and striking visual effect.
15. Uncropped Image: An image that has not been cropped or altered in its original dimensions, retaining all the content captured by the camera’s sensor.

V

1. Viewfinder: The optical or electronic window on a camera that allows photographers to see and compose their shots, either showing the scene directly or through the lens.
2. Vignetting: A gradual darkening of the edges of an image, either due to lens characteristics or added in post-processing for artistic effect.
3. VR (Vibration Reduction): A technology used in some lenses and cameras to reduce camera shake, allowing for sharper images when shooting handheld, particularly in low light or at slower shutter speeds.
4. Vertical Format: A composition in which the height of the image is greater than its width, commonly used for portraits or subjects that have a vertical emphasis.
5. Vivid: A term used to describe bright, intense colours in a photograph, often achieved through increased saturation or careful post-processing.
6. V-Log: A logarithmic colour profile used in video recording that preserves more dynamic range and detail, allowing for greater flexibility in colour grading during post-production.
7. Virtual Tour: A series of 360-degree panoramic images stitched together to create an immersive, interactive experience commonly used in real estate or travel photography.
8. Variable ND Filter: A neutral density filter that allows photographers to adjust the level of light reduction by rotating the filter, providing more flexibility for different lighting conditions.
9. Vibration Compensation (VC): A stabilisation system used in lenses or cameras to reduce blur caused by camera shake, particularly useful in handheld photography.
10. Visor Viewfinder: A type of viewfinder that uses a simple visor or hood to shade the viewfinder and prevent glare, commonly found on older or medium-format cameras.
11. Visual Storytelling: The art of conveying a narrative or message through photographs, often by capturing moments, emotions, and details that suggest a larger context or story.
12. Vertical Panoramic: A panoramic image captured in a vertical format, often used for tall subjects like buildings, trees, or mountains.
13. Volumetric Lighting: A lighting effect that simulates the scattering of light as it passes through the air, creating visible beams or rays of light, often used in dramatic or cinematic photography.
14. Video Frame Rate: The number of frames captured per second in video recording, typically measured in FPS (frames per second). Common frame rates include 24fps, 30fps, and 60fps.
15. V-Flat: A large, portable board used in studio photography to control light by either reflecting or blocking light, often made of foam core or similar materials.

W

1. White Balance: A camera setting that adjusts the colours in an image to make whites appear neutral, compensating for different types of lighting (e.g., daylight, tungsten, fluorescent).
2. Wide-Angle Lens: A lens with a short focal length (e.g., 16mm to 35mm) that captures a wider field of view, often used in landscape, architecture, and group photography.
3. WYSIWYG (What You See Is What You Get): Refers to the concept that the image displayed on the camera’s screen or computer monitor is an accurate representation of the final output, particularly when editing photos.
4. White Clipping: The loss of detail in the brightest areas of an image, where the highlights are so overexposed that they appear as pure white.
5. Watermark: A text or graphic overlay added to an image, typically for branding or copyright protection, making it harder for the image to be used without permission.
6. Wireless Flash Trigger: A device that wirelessly communicates between the camera and flash unit, allowing for off-camera flash setups without the need for physical connections.
7. Washing Out: When an image appears overly bright and lacks contrast, often due to overexposure or poor lighting conditions.
8. Wide Dynamic Range (WDR): The ability of a camera or sensor to capture a wide range of light intensities, from deep shadows to bright highlights, often resulting in more detailed images.
9. White Noise: A type of noise in digital images that appears as random, evenly distributed speckles or grain, often due to high ISO settings or long exposures.
10. Warm Colors: Colors that evoke warmth and energy, such as red, orange, and yellow, are often used to create a feeling of comfort or excitement in photographs.
11. Wide Gamut: A term used to describe the ability of a camera, monitor, or printer to reproduce a broad range of colours, important for achieving accurate and vibrant colour reproduction.
12. Waterproof Housing: A protective case for cameras or lenses that allows photographers to shoot underwater or in wet environments without damaging their equipment.
13. Wobble Effect: A visual distortion that can occur in video footage when using certain types of cameras or lenses, especially with handheld shots, creating a “jelly-like” motion.
14. Wireless Tethering: A technique where a camera is connected to a computer or tablet via Wi-Fi, allowing images to be viewed and transferred in real time without physical cables.
15. Window Light: Natural light that enters through a window, often used in portrait photography for its soft, diffused qualities.

X

1. X-Trans Sensor: A proprietary sensor technology developed by Fujifilm that uses a unique colour filter array to reduce moiré and improve colour reproduction without the need for an optical low-pass filter.
2. X-Sync: The maximum shutter speed at which a camera can fully expose the sensor while using a flash. Shooting faster than the X-sync speed can result in incomplete exposure from the flash.
3. XQD Card: A type of high-speed memory card used in some professional-grade cameras, known for its faster write speeds and durability compared to traditional SD cards.
4. Xenon Flash: A type of high-intensity flash that uses xenon gas to produce a bright, brief burst of light, commonly found in high-end external flash units.
5. X-Ray Photography: A specialised technique that uses X-rays instead of visible light to capture images, often used in medical, scientific, or industrial applications.
6. X-Rite ColorChecker: A popular tool used by photographers and videographers to ensure accurate colour reproduction during the capture and editing process.
7. XMP (Extensible Metadata Platform): A format for embedding metadata into image files, often used in Adobe software for tracking editing adjustments without altering the original image.
8. Xenon Arc Lamp: A type of continuous light source used in some high-end studio lighting setups, known for its consistent colour temperature and brightness.
9. X-Process: A term referring to cross-processing, a film photography technique where the film is developed using chemicals intended for a different type of film, resulting in unique colour shifts and contrast.
10. X-Stop: A method for ensuring consistent focus when zooming in or out during a shot, often used in video to prevent shifts in focus.
11. X-Out: A term used in the photography industry to describe an image that has been rejected or marked for deletion, often due to technical flaws or poor composition.
12. X-Band Lighting: A specific type of lighting pattern used in scientific or industrial photography to highlight certain features or materials in an object.
13. Xenon Gas: The inert gas used in high-powered flashes to produce a bright, controlled burst of light for illuminating subjects in low-light environments.
14. X-Stop Exposure: A term used to describe the incremental adjustments made to the exposure settings of a camera during a shot, often in small fractions of a stop.
15. X-Factor: A colloquial term used in photography to describe an unquantifiable element of an image that makes it stand out or emotionally impactful, often related to composition, lighting, or subject matter.

Y

1. Yellow Filter: A filter often used in black-and-white photography to darken blue skies and increase contrast, making clouds more prominent.
2. YUV Color Space: A colour encoding system used in video and digital imaging that separates luminance (Y) from chrominance (U and V), reducing the amount of data needed while maintaining image quality.
3. Yaw: A term used in aerial photography to describe the rotation of a drone around its vertical axis, affecting the angle of the camera and framing of the shot.
4. Yashica: A Japanese camera brand known for its rangefinder and medium-format film cameras, popular in the mid-20th century.
5. Yongnuo: A Chinese brand known for producing affordable photography accessories, including flashes, lenses, and wireless triggers, often used by budget-conscious photographers.
6. Y-Lighting: A lighting technique where two light sources are positioned in a Y-shaped pattern, with the subject at the intersection, creating a balanced and evenly lit scene.
7. Yield Ratio: A term used in printing to describe the amount of usable image area compared to the total print area, often relevant when cropping or resizing images.
8. YUV Compression: A method of compressing video data by separating luminance and chrominance information, reducing the file size without significantly affecting image quality.
9. Yearbook Photography: A specialised genre of photography focused on capturing school events, portraits, and group photos for inclusion in yearbooks.
10. Yard Photography: A colloquial term referring to landscape or outdoor photography focused on capturing natural or rural settings, such as farms, backyards, or fields.
11. Yankee Flash: An older term used to describe a specific type of flash unit popular in the mid-20th century, known for its reliability and ease of use in studio photography.
12. Y-Composition: A compositional technique where the elements of the image form a Y-shaped pattern, guiding the viewer’s eye through the photograph.
13. Yarn Filter: A creative photography technique where a piece of yarn or similar material is placed in front of the lens to create abstract patterns and textures in the image.
14. Yosemite Effect: A term used to describe a dramatic increase in interest or visitation to a location after it has been featured in a popular photograph or media, named after the iconic photographs of Yosemite National Park.
15. Yaw Stabilization: A feature in some gimbals and drones that automatically corrects for unwanted rotational movement, keeping the camera steady during flight or movement.

Z

1. Zoom Lens: A lens with a variable focal length, allowing photographers to change the magnification of their subject without physically moving closer or farther away (e.g., 24-70mm).
2. Zone System: A photographic technique developed by Ansel Adams that divides the tonal range of an image into 11 zones, allowing photographers to control exposure and contrast with precision.
3. Zebra Pattern: A camera feature that overlays striped patterns on overexposed areas in the viewfinder or monitor, helping photographers avoid blown highlights.
4. Zoom Creep: A phenomenon where the zoom lens extends or retracts under its weight, especially when the camera is pointed upward or downward, often seen in older or lower-quality lenses.
5. Z-Stop: A term used in video production to describe a specific point in the zoom range where the focus is locked, ensuring consistent focus during zoom transitions.
6. Zonal Metering: A metering technique where the camera measures light from specific zones in the frame, providing a more accurate exposure reading for high-contrast scenes.
7. Zoom Ratio: The ratio between the shortest and longest focal lengths of a zoom lens (e.g., a 3x zoom lens can go from 50mm to 150mm).
8. Z-Depth: A term used in 3D imaging and photography to describe the distance of objects from the camera, often used in depth-of-field calculations or creating depth maps in post-processing.
9. Zoom Framing: A technique where the zoom lens is used to change the framing of a shot without moving the camera, often used to maintain consistent composition during movement.
10. Z-Fold Booklet: A type of printed booklet where the pages are folded in a Z-shape, often used in portfolio presentations or promotional materials for photographers.
11. Zebra Striping: A visual effect created by applying alternating light and shadow patterns to an image, often used for creative or abstract photography.
12. Zoom Burst: A creative effect achieved by zooming in or out while taking a photo with a slow shutter speed, resulting in streaks of light or colour radiating from the centre of the image.
13. Zonal Focusing: A technique where the photographer pre-focuses the lens to cover a specific distance range, allowing them to capture fast-moving subjects without constantly refocusing.
14. Z-Index: A term used in digital imaging and video to describe the layering order of elements, such as text, images, or objects, with higher Z-index values appearing in front of lower values.
15. Zoom Lock: A feature on some zoom lenses that locks the lens in place to prevent zoom creep or accidental changes in focal length during transport or shooting.