The Scheimpflug principle defines an optical geometry in which the object plane (plane of sharp focus), the lens plane, and the image plane (sensor or film) intersect along a single common line. When the lens is tilted relative to the image plane, the plane of sharp focus also tilts, allowing inclined or slanted surfaces to appear uniformly sharp.
In a standard setup, the image and lens planes are parallel, which restricts the depth of field and only makes parallel objects fully sharp. Applying the Scheimpflug condition aligns the depth of field distribution with the orientation of the object, reducing the need for small apertures and avoiding diffraction limits.
Application fields
Photography and cinematography: Large-format and tilt-shift lenses use this principle to extend the depth of field across tilted subjects (e.g. architectural façades or product shots) or to create selective focus effects.
Microscopy and optical metrology: It ensures sharp imaging of tilted specimens or samples, thereby improving measurement accuracy in 3D microscopy or surface profiling.
Machine vision and industrial inspection: This is critical for imaging slanted objects on conveyor belts, such as semiconductor wafers, printed circuit boards or packaging, where precise edge detection and dimensional accuracy are required.
Aerial mapping and topographic imaging: Maintains focus across oblique landscapes or infrastructure to support accurate geospatial data acquisition.
Medical imaging: Widely used in ophthalmology for Scheimpflug cameras, it enables the acquisition of highly precise cross-sectional images of the cornea and anterior chamber.
The Scheimpflug principle is essentially a fundamental concept in optical engineering wherever non-parallel object planes need to be imaged with maximum sharpness and minimal compromise on resolution or depth of field.
