Panoramic photography

There is no formal definition for the point at which "wide angle" leaves off and "panoramic" begins, but a truly panoramic image ought to capture a field of view comparable to (or greater than) that of the human eye, which is about 160° by 75°, and should do so while maintaining sharp detail across the entire picture.

Photofinishers and manufacturers of APS-system cameras use the word "panoramic" to refer to any print format with a wide aspect ratio; for example, a print which is 11.5" wide x 4" high (an aspect ratio of nearly 3:1, or nearly twice as wide as a traditional 6" x 4" print). A typical APS camera in its so-called "panoramic" mode, with its zoom lens at its shortest focal length of 24 mm, has a field of view of only 65°, which most photographers would classify as merely wide angle (and a moderate wide angle at that).

90° is about the widest field of view that can be captured with normal sharpness and without gross distortion by a traditional lens and camera using a single, flat piece of film. A 17 mm. lens on a traditional 35mm camera is an example of such a lens. Lenses that capture wider angles—up to 180°—exist, but are commonly known as fisheye lenses and exhibit extreme geometrical distortion and lack of sharpness and brightness at the edges.

True panoramic photography, then, requires specialized equipment and techniques.

Conceptually, the simplest technique is merely to take a series of conventional photographs with slightly overlapping fields of view, and join them at the edges. In the days before digital photography, countless amateur and professional photographers attempted to create panoramic views in this way and found that the craftsmanship needed to match the images and hide the seams was all but unattainable. However, modern digital cameras and software are capable of stitching multiple images together with excellent results, and as of 2004 this is probably the most common technique for creating panoramic images. The Cinerama motion picture process used three cameras, projectors, and strips of film to achieve a 146° x 55° field of view with spectacular sharpness and detail (and noticeable seams).

Rotating panoramic cameras such as the Kodak Cirkut have been in use for nearly 150 years. A clockwork mechanism rotates the camera continuously and evenly and simultaneously pulls the film through the camera, in such a way that the speed of the film matches the speed with which the image moves across the image plane. Exposure is made through a narrow slit. In effect, such a camera performs continuous, seamless version of the "overlapping-image" technique. Using only central part of the image field produces a very sharp picture whose characteristics are very even from edge to edge. These cameras were and are widely used for group pictures, particularly of athletic teams. Such a camera can, of course, capture a full 360° in the horizontal plane.

The same principle on a reduced scale is used in swing-lens panoramic cameras such as the Widelux and Noblex. Here, the film remains stationary. Rather than being held flat as in a traditional camera, it is curved into a near-semicircle. As the photograph is taken, the lens pivots around its nodal point while, at the same time, a moving slit exposes the vertical strip of film that is aligned with the axis of the lens. The exposure takes only a fraction of a second. Physical and mechanical considerations limit the field of view of such camera to about 140°. (Even so, photographers must grip the camera carefully to avoid having their fingertips appear in the finished picture).

Examples of panoramic photographs are this one of Riddarfjärden in Stockholm:

(Larger image)

and this one (1 Meg) taken from the top of The London Eye

External links