Editing View camera (section)

==Lenses==
{{More citations needed|date=January 2008}}
A view camera [[photographic lens|lens]] typically consists of: 
* A ''front lens element''— sometimes referred to as a ''cell.''
* A ''[[shutter (photography)|shutter]]''—an electronic or spring-actuated mechanism that controls exposure duration. Some early shutters were air-actuated. For long exposures, a lens with no shutter (a ''barrel lens'') can be uncovered for the duration of the exposure by removing a lens cap.
* The [[aperture]] diaphragm
* A ''[[lensboard]]''—a flat board, typically square in shape and made of metal or wood, that locks securely into the front standard of a particular view camera, with a central hole of the right size to insert a lens and shutter assembly, usually secured and made light-tight by screwing a ring onto a thread on the rear of the lens assembly. Lensboards, complete with lenses, can be removed and fitted quickly.
* A ''rear lens element'' (or cell).

Almost any lens of the appropriate coverage area may be used with almost any view camera. All that is required is that the lens be mounted on a lensboard compatible with the camera. Not all lensboards work with all models of view camera, though different cameras may be designed to work with a common lensboard type. Lensboards usually come with a hole sized according to the shutter size, often called the Copal Number. [[Copal (company)|Copal]] is the most popular maker of [[leaf shutter]]s for view camera lenses.

The lens is designed to split into two pieces, the front and rear elements screwed, usually by a trained technician, into the front and back of the shutter assembly, and the whole fitted in a lensboard.

View camera lenses are designed with both [[focal length]] and coverage in mind. A 300&nbsp;mm lens may give a different angle of view (either over 31° or over 57°), depending on whether it was designed to cover a 4×5 or 8×10 image area. Most lenses are designed to cover more than just the image area to accommodate camera [[#Movements|movements]].

Focusing involves moving the entire front standard with the lens assembly closer to or further away from the rear standard, unlike many lenses on smaller cameras in which one group of lens elements is fixed and another moves.

Very [[long focus lens]]es may require that the camera be fitted with special extra-long rails and bellows. Very short focal length wide-angle lenses may require that the standards be closer together than a normal [[concertina]]-folded bellows allows. Such a situation requires a ''bag bellows'', a simple light-tight flexible bag. Recessed lensboards are also sometimes used to get the rear element of a wide angle lens close enough to the film plane; they may also be of use with [[telephoto lens]]es, since these compressed long-focus lenses may also have very small spacing between the back of the lens and the film plane.

[[Zoom lens]]es are not used in view camera photography, as there is no need for rapid and continuous change of focal length with static subjects, and the price, size, weight, and complexity would be excessive. Some lenses are "[[convertible lens|convertible]]": the front or rear element only, or both elements, may be used, giving three different focal lengths, though the quality of the single elements is not as good at larger apertures as the combination. These are popular with field photographers who can save weight by carrying one convertible lens rather than two or three lenses of different focal lengths.

[[Soft focus]] lenses introduce [[spherical aberration]] deliberately into the optical formula for an [[wikt:ethereal|ethereal]] effect considered pleasing, and flattering to subjects with less than perfect complexions. The degree of soft-focus effect is determined by either [[aperture]] size or special disks that fit into the lens to modify the aperture shape. Some antique lenses, and some modern SLR soft focus lenses, provide a lever that controls the softening effect by altering the optical formula.