Glossary

This page is very much a work in progress. At present, it consists mostly of a few terms, mostly undefined. When complete, it is intended to have definitions for all the technical terms used in the book.

Diopter:     A number that measures the strength lens. This is the number that tells how strong a close-up attachment is, with bigger numbers indicating more strength. Typical values for this purpose range from 1 to 5 or so. Technically, the diopter value is the reciprocal of the lens focal length, measured in meters. So a 2-diopter closeup lens has focal length ½ meter.

Bellows:   

Extension Tube:  A hollow tube that can be placed between the lens and camera body to give the lens more extension (distance from the sensor) and hence a closer focusing ability. The tube has appropriate fittings on front and back to mount to the camera and to the lens.   

Focal Length: Macro Lens:

ISO: A measure of the sensitivity of the sensor to light. Higher numbers indicate more sensitivity.

f/stop

Aperture

Shutter: 

Shutter Speed: The length of time that the shutter is open, allowing light to reach the sensor. Typically expressed as a fraction of a second.

Sensor

Body

Lens