Panoramic photography
Panoramic photography is a technique of photography, using specialized equipment or software, that captures images with horizontally elongated fields of view. It is sometimes known as wide format photography. The term has also been applied to a photograph that is cropped to a relatively wide aspect ratio, like the familiar letterbox format in wide-screen video.
While there is no formal division between “wide-angle” and “panoramic” photography, “wide-angle” normally refers to a type of lens, but using this lens type does not necessarily make an image a panorama. An image made with an ultra wide-angle fisheye lens covering the normal film frame of 1:1.33 is not automatically considered to be a panorama. An image showing a field of view approximating, or greater than, that of the human eye – about 160° by 75° – may be termed panoramic. This generally means it has an aspect ratio of 2:1 or larger, the image being at least twice as wide as it is high. The resulting images take the form of a wide strip. Some panoramic images have aspect ratios of 4:1 and sometimes 10:1, covering fields of view of up to 360 degrees. Both the aspect ratio and coverage of field are important factors in defining a true panoramic image.
A panorama of Sydney featuring (from left) the Sydney Opera House, the central business district skyline, and the Sydney Harbour Bridge.
Photo-finishers and manufacturers of Advanced Photo System (APS) cameras use the word “panoramic” to define any print format with a wide aspect ratio, not necessarily photos that encompass a large field of view. In fact, a typical APS camera in its panoramic mode, where its zoom lens is at its shortest focal length of around 24 mm, has a field of view of only 65°, which many photographers[who?] would only classify as wide-angle, not panoramic
Short rotation
A 1900 advertisement for a short rotation panoramic camera
Short rotation, rotating lens and swing lens cameras have a lens that rotates around the camera’s rear nodal point and use a curved film plane.[14] As the photograph is taken, the lens pivots around its nodal point while a slit exposes a vertical strip of film that is aligned with the axis of the lens. The exposure usually takes a fraction of a second. Typically, these cameras capture a field of view between 110° to 140° and an aspect ratio of 2:1 to 4:1. The images produced occupy between 1.5 and 3 times as much space on the negative as the standard 24 mm x 36 mm 35 mm frame.
Cameras of this type include the Widelux, Noblex, and the Horizon. These have a negative size of approximately 24×58 mm. The Russian “Spaceview FT-2”, originally an artillery spotting camera, produced wider negatives, 12 exposures on a 36-exposure 35 mm film.
A negative from a 35 mm swing lens camera
Short rotation cameras usually offer few shutter speeds and have poor focusing ability. Most models have a fixed focus lens, set to the hyperfocal distance of the maximum aperture of the lens, often at around 10 meters (30 ft). Photographers wishing to photograph closer subjects must use a small aperture to bring the foreground into focus, limiting the camera’s use in low-light situations.
The distortion of architectural subjects is severe when using a rotating lens camera
Rotating lens cameras produce distortion of straight lines. This looks unusual because the image, which was captured from a sweeping, curved perspective, is being viewed flat. To view the image correctly, the viewer would have to produce a sufficiently large print and curve it identically to the curve of the film plane. This distortion can be reduced by using a swing-lens camera with a standard focal length lens. The FT-2 has a 50 mm while most other 35 mm swing lens cameras use a wide-angle lens, often 28 mm].[citation needed]
A digital camera image of Franklin D. Roosevelt East River Drive made with a Sony Cyber-shot, showing faults (discontinuities) caused by objects in fast motion during image capture. The panorama is stitched from multiple exposures taken while the camera is manually rotated.
Full rotation
360-degree panoramic projection of the VLT survey telescope.[15]
Rotating panoramic cameras, also called slit scan or scanning cameras are capable of 360° or greater degree of rotation. A clockwork or motorized mechanism rotates the camera continuously and pulls the film through the camera, so the motion of the film matches that of the image movement across the image plane. Exposure is made through a narrow slit. The central part of the image field produces a very sharp picture that is consistent across the frame.[citation needed]
Digital rotating line cameras image a 360° panorama line by line. Digital cameras in this style are the Panoscan and Eyescan. Analogue cameras include the Cirkut (1905), Leme (1962), Hulcherama (1979), Globuscope (1981) and Roundshot (1988).
Fixed lens
Fixed lens cameras, also called flatback, wide view or wide field, have fixed lenses and a flat image plane. These are the most common form of panoramic camera and range from inexpensive APS cameras to sophisticated 6×17 cm and 6×24 cm medium format cameras. Panoramic cameras using sheet film are available in formats up to 10×24 inches. APS or 35 mm cameras produce cropped images in a panoramic aspect ratio using a small area of film. Advanced 35 mm or medium format fixed-lens panoramic cameras use the full height of the film and produce images with a greater image width than normal.[citation needed]
Pinhole cameras of a variety of constructions can be used to make panoramic images. A popular design is the ‘oatmeal box’, a vertical cylindrical container in which the pinhole is made in one side and the film or photographic paper is wrapped around the inside wall opposite, and extending almost right to the edge of, the pinhole. This generates an egg-shaped image with more than 180° view.[16]
Because they expose the film in a single exposure, fixed lens cameras can be used with electronic flash, which would not work consistently with rotational panoramic cameras.
With a flat image plane, 90° is the widest field of view that can be captured in focus and without significant wide-angle distortion or vignetting. Lenses with an imaging angle approaching 120 degrees require a center filter to correct vignetting at the edges of the image. Lenses that capture angles of up to 180°, commonly known as fisheye lenses exhibit extreme geometrical distortion but typically display less brightness falloff than rectilinear lenses.[citation needed]
Examples of this type of camera are: Hasselblad X-Pan (35 mm), Linhof 612PC, Horseman SW612, Linhof Technorama 617, Tomiyama Art Panorama 617 and 624, and Fuji G617 and GX617 (Medium format (film)).
The panomorph lens provides a full hemispheric field of view with no blind spot, unlike catadioptric lenses.[citation needed]