Camera lens
A camera lens is an optical device that forms an image on a camera sensor, photographic film or another light-sensitive surface. In photography, a lens collects light from the scene, focuses it on the camera and strongly affects the angle of view, perspective, sharpness, aperture, depth of field and background blur.
Purpose and construction
The main task of a lens is to create a sharp and correctly illuminated image on the sensor. A modern photographic lens usually includes optical elements, an aperture diaphragm, a focusing mechanism, a camera mount, electronic contacts and, in some models, image stabilization and an autofocus motor.
The lens affects not only technical quality but also artistic rendering. Different lenses can produce different perspective, geometric distortion, background blur and detail rendering even on the same camera.
Fixed and interchangeable lenses
Fixed lenses are built into smartphones, compact cameras, action cameras and some video cameras. They cannot be replaced by the user. Interchangeable lenses are attached through a camera mount and can be changed according to the task. They are used with DSLR and mirrorless system cameras.
Main characteristics
Focal length and angle of view
Focal length is measured in millimetres and determines magnification and angle of view. A shorter focal length gives a wider view; a longer focal length makes distant subjects appear larger. Sensor size is also important: the same lens gives different framing on full-frame, APS-C and Micro Four Thirds cameras.
Approximate classification for full-frame cameras:
| Lens type | Focal length | Typical use |
|---|---|---|
| Fisheye | 8-15 mm | creative distortion, panoramas, interiors |
| Ultra-wide-angle | 14-24 mm | landscapes, architecture, interiors |
| Wide-angle | 24-35 mm | travel, street, reportage |
| Standard | 35-70 mm | everyday photography, portraits, reportage |
| Telephoto | 70-300 mm | portraits, sport, animals, distant subjects |
| Super-telephoto | 300 mm and longer | wildlife, aviation, sport at long distances |
Angle of view shows how much of the scene enters the frame. Nikon lists a 114° angle of view on the FX format for one of its 14 mm lenses.[1]
Aperture and lens speed
The aperture is an adjustable opening inside the lens. It is written as an f-number, such as f/1.8, f/2.8 or f/11. The smaller the f-number, the more light reaches the sensor.[2] A lens with a large maximum aperture, such as f/1.4 or f/2.8, is called a fast lens. It is useful in low light and for shallow depth of field.
Focusing and stabilization
Focusing can be manual or automatic. The minimum focusing distance indicates how close a subject can be while the lens can still focus. Macro lenses are designed for close-up photography and can reproduce small subjects at high magnification.
Some lenses include optical image stabilization, called IS, VR, OSS or OIS depending on the manufacturer. Stabilization compensates for small camera movements and helps with handheld shooting, but it does not freeze a moving subject.[3]
Mount and compatibility
A lens mount is the mechanical and electronic connection between the lens and camera body.[4] Camera systems use different mounts, such as Canon EF and RF, Nikon F and Z, Sony E, Fujifilm X and Micro Four Thirds. Canon notes that EF lenses can be used on EOS R cameras with an EF-EOS R adapter.[5]
Types of lenses
A fisheye lens gives an extremely wide view and strong distortion. A wide-angle lens is used for landscapes, architecture and interiors. A standard lens gives a natural-looking perspective and is suitable for everyday photography. A macro lens is designed for close-up photographs of small subjects. A telephoto lens is used for distant subjects, sport, wildlife and portraits with strong background blur. An all-in-one zoom covers a broad range and is convenient for travel.
By construction, lenses are also divided into prime lenses, which have one focal length, and zoom lenses, which allow focal length to be changed.
Image quality
Lens quality depends on sharpness, contrast, chromatic aberration, distortion, vignetting, flare resistance and the character of bokeh. Modern cameras and software can correct some optical flaws, but lens quality remains important.
How to choose a lens
When choosing a lens, it is important to consider the camera mount, sensor size, focal length, maximum aperture, stabilization, size, weight, autofocus and price.
| Task | Suitable lenses |
|---|---|
| Landscapes and architecture | wide-angle and ultra-wide-angle lenses |
| Portraits | 50 mm, 85 mm, 70-200 mm, fast primes and zooms |
| Travel | all-in-one zooms such as 24-105 mm, 24-200 mm or 18-135 mm |
| Macro | macro lenses around 60-105 mm and longer |
| Sport and wildlife | telephoto lenses such as 70-200 mm, 100-400 mm or 150-600 mm |
| Video | lenses with quiet autofocus, stabilization and a useful focal range |
Common mistakes
Common mistakes include buying a lens without checking compatibility, looking only at zoom range, ignoring aperture, choosing a lens that is too heavy, and expecting an expensive lens to improve composition and lighting automatically.
See also
References
- ↑ AF NIKKOR 14mm f/2.8D ED. Nikon USA.
- ↑ What Is Aperture Photography?. Canon U.S.A.
- ↑ Vibration Reduction. Nikon USA.
- ↑ О креплении объективов
- ↑ Canon Lenses. Canon U.S.A.