Shift to correct converging verticals — rise and fall
When the camera is angled up, say at a building, the building appears to lean backwards— keystoning. This is caused by the non-parallel alignment of the film/sensor plane and the subject.
The shift function of the lens allow the correction of such effects; the camera can be positioned so as to be parallel to the building or similar subject, then the lens can be shifted upwards (“rise”) to include the subject, all while remaining parallel to it. The same principle applies in shifting the lens down (“fall”).
Essentially, a shift-capable lens is a WIDE ANGLE OF VIEW LENS (not to be confused with focal length!), that allows the photographer to choose what section of the image circle to record.
Magic depth of field with tilt or swing
Article continues for subscribers...
If you’re already a subscriber, CLICK HERE TO LOG IN
diglloyd Advanced Photography includes hundreds of pages of exclusive coverage and high resolution, Retina-grade example pictures detailing Canon and Nikon DSLR bodies and their lenses, with in-depth analysis of sharpness and contrast, color, bokeh, vignetting, distortion, MTF, and flare. Also included is a wealth of in-context technique and workflow insight. Since 2006, diglloyd Advanced Photography is the authoritative review and on-line reference for discerning Canon and Nikon shooters. Subscriptions cost $ per year.