Camera FOV Guide
What is Camera Field of View (FOV) and Why It Matters
Camera Field of View (FOV) refers to the extent of the observable world that a camera can capture at once. FOV is determined by the lens focal length and camera sensor size, expressed in degrees. For example, a 50mm lens on a full-frame camera provides a horizontal FOV of about 40 degrees, but the same lens on an APS-C camera narrows to about 27 degrees.
FOV is a crucial element in photography and videography. Wide FOV (wide angle) is suitable for landscapes, architecture, and group photos, while narrow FOV (telephoto) is advantageous for portraits, wildlife, and sports. Wider FOV captures more area but makes subjects appear smaller, while narrower FOV magnifies subjects but limits coverage.
FOV calculation is essential for professional work like CCTV installation, drone photography, studio setup, and event coverage. Calculating coverage area at specific distances helps plan shoots efficiently and select appropriate equipment accurately. Understanding FOV also makes concepts like crop factor and equivalent focal length easier to grasp.
Sensor Size FOV Differences and Understanding Crop Factor
Camera sensor size directly impacts FOV. Full-frame sensors (36×24mm) are the same size as 35mm film and provide the widest FOV. APS-C sensors have a crop factor of about 1.5-1.6x compared to full-frame, with Canon at 1.6x and Nikon/Sony at 1.5x. Micro Four Thirds sensors have a 2.0x crop factor.
Crop factor indicates how FOV changes when mounting the same lens on different sensors. For example, a 50mm lens on full-frame provides 50mm FOV, but on APS-C Canon (1.6x) it narrows to 80mm equivalent FOV. This is expressed as "equivalent focal length 80mm". Therefore, APS-C requires shorter focal length lenses to achieve the same FOV as full-frame.
Smartphone cameras use very small sensors like 1/2.3" or 1/1.7", resulting in crop factors of 5-7x. A smartphone's 24mm lens has an actual physical focal length of about 4-5mm, but due to the small sensor provides full-frame equivalent 24mm FOV. Recent flagship smartphones incorporate 1-inch class sensors to reduce crop factor to 2.7x and improve image quality.
FOV and Applications by Focal Length - Wide to Super Telephoto
FOV and applications vary completely by focal length. Ultra-wide (14-24mm) provides horizontal FOV over 90 degrees, essential for landscape, architecture, and real estate photography. Used to capture wide interior spaces in one frame or express grand landscapes. However, severe distortion can curve straight lines, leading to tilt-shift lens use for architectural photography.
Wide angle (24-35mm) offers horizontal FOV of 60-84 degrees, suitable for street photography, documentary, and travel. 24mm is a versatile FOV preferred by many photographers for capturing landscapes and daily life naturally. 35mm is the FOV closest to "human vision" and particularly popular in street photography, providing minimal distortion and natural perspective.
Standard (50mm) provides horizontal FOV around 40 degrees, widely used for portraits, food, and product photography. Called the "standard lens", it expresses subjects with natural vision. Telephoto (70-200mm) offers horizontal FOV of 12-29 degrees, suitable for portrait close-ups, sports, and wildlife. It compresses backgrounds and creates beautiful bokeh. Super telephoto (300mm+) has FOV below 8 degrees, dedicated to bird, wildlife, and long-distance sports photography.
Practical FOV Calculation Guide for CCTV Installation
FOV calculation is essential for CCTV installation. Accurately understanding surveillance coverage helps determine camera quantity and positions for complete monitoring without blind spots. CCTV typically uses 2.8mm lenses (horizontal FOV ~90°), 3.6mm (~80°), 6mm (~50°), 8mm (~40°), and 12mm (~25°).
Indoor spaces (stores, offices) suit wide FOV 2.8-3.6mm lenses. For example, shooting from 3m height with a 2.8mm lens covers approximately 10m horizontally and 7m vertically. Parking lots or building entrances benefit from 6mm lenses for focused area monitoring. A 6mm lens at 10m distance clearly captures about 8m horizontal range.
Outdoor long-distance surveillance requires 8-12mm lenses. For detailed information needs like parking lot license plate recognition or building entrance face identification, narrow FOV must magnify subjects. Recently, motorized zoom lenses (PTZ cameras) allow remote adjustment from 2.8-12mm, enabling various FOV uses with one camera. Using a FOV calculator allows accurate coverage simulation before installation.
FOV Utilization Tips for Drone and Action Camera Shooting
In drone photography, FOV is a key element determining shooting style. DJI Mini series uses 24mm equivalent FOV (83° FOV) suitable for general landscape and real estate photography. DJI Air and Mavic series provide similar FOV, and shooting from 50-100m altitude captures approximately 100-200m horizontal range in one frame.
Actual coverage varies greatly depending on drone gimbal angle and altitude. Setting the gimbal horizontal (0°) allows distant shooting, while vertical downward (-90°) provides accurate orthophotos. For real estate, shooting from 100m altitude at 45° angle balances entire buildings with surrounding environment.
Action cameras (GoPro, DJI Osmo Action) use ultra-wide lenses (FOV 120-150°) to create dynamic footage. Wide FOV enables immersive first-person perspective footage, but severe distortion curves straight lines. Recent action cameras offer "linear mode" providing FOV 90-100° footage with distortion correction. For sports like skiing, surfing, and cycling, using SuperView (up to 155°) creates even more thrilling footage.
FOV Selection Strategy for Film and Broadcasting
In film and broadcast production, FOV selection is core to storytelling. Wide FOV emphasizes space and background to convey environmental importance, while narrow FOV focuses on characters and emotions. Hollywood films traditionally use 35mm, 50mm, and 85mm as standards, with each lens optimized for specific shots.
35mm suits "master shots" or "two shots", showing characters and background together for natural dialogue scenes. 50mm is ideal for "medium shots", naturally capturing character upper bodies. 85mm is used for "close-ups" and "insert shots", delicately expressing facial expressions and emotions. Backgrounds blur beautifully, highlighting subjects.
For cinematic feel, consider anamorphic lenses. Anamorphic lenses create 2.39:1 widescreen aspect ratios with unique flare and bokeh. Broadcasting primarily uses zoom lenses like 24-70mm and 70-200mm. News, sports, and documentaries must respond to rapidly changing situations, making zoom lenses essential for FOV adjustment without lens changes.
