These before and after pics were taken hand held, to show ease of use, with a 24mm shift lens. After all, it is a normal visual phenomenon! I almost always leave a little convergence. It is the best way to make a building look as if it will fall on top of you and one of my long-time pet hates in architectural photography. For those new to camera movements my opinion is to never correct converging verticals into perfect parallels. Shifting at one of these angles is the same as using a shift combined with a rising front movement on a view camera. They can also be rotated to facilitate vertical and horizontal shooting but as well as this and very importantly, they can be set to shift at angles of 30° and 60° to the horizontal. Shift lenses can move sideways and up and down to control perspective and key-stoning (converging verticals). So being able to estimate the correct distance is a valuable skill to have. Also, sometimes the intersecting point occurs behind a wall, tree or even underground. When using 35mm formats on many occasions even a good guess will suffice as being ou t by 10cm or so over a metre will only mean an error of a fraction of a degree of tilt – jus t about impossible to set on these lenses or to see the difference in practical use. The nearer th e object plane is to the camera, the more accurate the measurement should be. The most important distance we need to know or measure is the distance parallel from th e lens axis to the intersection of the plane on which the main subject lies. Green is the film plane, Yellow is the lens plane and Blue is the object plane which is actually wedge shaped,Įxtending out from the intersection, varying in size with aperture and lens focal length selected. This is my old Linhof Technika showing its extreme range of movements and a very simplified diagram of the Scheimpflug rule in action. For my simple focusing technique, knowing how far the object plane lies in relation to the lens axis is very important. Theodor Scheimpflug (1865-1911) stated that ‘ when the extended lines from the lens plane, the object plane and the film plane intersect at the same point, the entire subject plane is in focus.’ I won’t go into a detailed explanation, as much has already been written on the subject, but I hope the diagram below illustrates the concept. This is the classic illustration of the Scheimpflug rule in action. For example, by tilting the lens forward by the right distance, a photographer is able to adjust the plane of focus to run along the ground, giving a vastly increased apparent depth of field, even with the lens wide open! These cameras, with their fine mechanical controls, have the ability to move this slice of space to the left and right, up and down and most importantly tilt and swing it away from the perpendicular. Tilt shift lenses are designed to emulate the camera movements found on larger monorail and technical field cameras. A slice of focused space if you like, that also moves forward and backward, but always parallel to the film plane. The lens can move forward and backward creating a plane of sharp focus in front of it. With normal 35mm camera lenses, the axis of the lens is mounted in a fixed position at right angles to the film plane. Thanks to David Summerhayes for permission to reprint this tutorial here. It is intended to provide a more in-depth explanation of the principals involved in using this type of lens. This article is published coincident with this site’s May, 2008 report on the new Nikon 24mm PC-E lens.
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