Sentence examples for a focal length from inspiring English sources

It has a 3.8X optical zoom lens with a focal length of 28 to 105 millimeters.

I eliminated the neck pain associated with prolonged computer use by getting glasses specifically prescribed for the computer, with a focal length greater than the usual reading distance.

For example, if the objective has a focal length of 254 cm (100 inches) and the eyepiece has a focal length of 2.54 cm (1 inch), then the magnification will be 100.

A normal camera lens usually has a focal length approximately equal to the diagonal of the picture format covered.

The long optical lens offers a focal length of 28-300 millimeters, but it is not removable, making this $500 camera a step down from more expensive digital single-lens reflex cameras.

Historically, most major camera makers sold only a single macro lens, usually with a focal length of about 50 millimeters, which provided a more or less normal field of view on a 35-millimeter film camera.

They are magnifying or reducing telescopes without a focal length (hence afocal), yielding a virtual image that the camera lens projects onto the film.

In 1845 Lord Rosse constructed in Ireland a reflector with a 185-cm (73-inch) mirror and a focal length of about 16 metres (52 feet).

The unifocal standard lens has a focal length equivalent to 47mm in the 35mm format.

The collimator has a focal length of 250 mm.

The primary reflector dish has a focal length of 200 mm and is a focal with the secondary inverse reflector which has a focal length of 70 mm.