Lenses

F-Stops

It is important to note that the smaller the iris opening, the more times it can be divided into the focal length. Therefore, as the iris opening becomes smaller, the f-stop number becomes higher. So a lower f-stop number means more light (a larger opening), and a higher f-stop number means less light (a smaller opening)

Malkiewicz, K, Cinematography: The Classic Guide to Filmmaking, Revised and Updated for the 21st Century, P.13

Zoom Lens

All zoom lenses require the same focusing procedure: you open up the aperture fully to reduce depth of field, zoom all the way in on the subject, and closely examine the sharpness

Malkiewicz, K, Cinematography: The Classic Guide to Filmmaking, Revised and Updated for the 21st Century, P.15


Macro Lens

For close-up work macro lenses focus as close as a few centimetres away without the use of special attachments

Malkiewicz, K, Cinematography: The Classic Guide to Filmmaking, Revised and Updated for the 21st Century, P.16

Perspective

From the same distance, three different lenses - wide, normal and telephoto - change the area of view but not the perspective. By using the same three lenses and changing the distances to the subject, we can remain the same field of view but with different perspectives.