Archive for the ‘Optical’ Category

Lens Vignetting

In photography, lens vignetting is a reduction of an image’s brightness or saturation at the corners compared to the image center. The word vignette originally referred to a decorative border in a book. Later, the word came to be used for a photographic portrait which is clear in the center, and fades off at the edges. […]

Camera Field of View

The camera field of view is determined by the angle of view from the lens out to the scene and can be measured vertically or horizontally. Because the aspect ratio differs between formats, the more universal camera field of view is calculated along the diagonal of the scene. A shorter focal length (such as a […]

Perspective In Photography

If you photograph a subject with a tele lens and want it to have the same size on the sensor when photographing it with a wide angle lens, you would have to move closer to the subject. Because this would cause the perspective to change, lenses with different focal lengths are said to have a […]


In photographic terms, “macro” means the optical ability to produce a 1:1 or higher magnification of an object on the sensor. For instance if you photograph a aquarium shrimp with an actual size of 21.6 mm so that it fills the 35mm sensor (43.3mm diagonal), the shrimp gets magnified with a ratio of 43.3 to […]


Distortion is a deviation from rectilinear projection, a projection in which straight lines in a scene remain straight in an image. It is a form of optical aberration. Although distortion can be irregular or follow many patterns, the most commonly encountered distortions are radially symmetric, or approximately so, arising from the symmetry of a photographic […]