The Camera

-Diaphragm- To reduce the aperture of (a lens, camera, etc.) by means of a diaphragm.
-Parallax- The difference between the view of an object as seen through the picture taking lens of a camera and the view as seen through a seperate viewfinder.
-Pentaprism- A prism that has five faces, a pair of which are at 90° to each other; a ray entering one of the pair emerges from the other at an angle of 90° to its original direction: used esp. in single-lens reflex cameras to reverse images laterally and reflect them to the viewfinder.
-Corfield- The entire range of wavelengths or frequencies of electromagnetic radiation extending from gamma rays to the longest radio waves and including visible light.

-Aperture- A usually adjustable opening in an optical instrument, such as a microscope, a camera, or a telescope, that limits the amount of light passing through a lens or onto a mirror.
-Shutter- A mechanical device for opening and closing the aperture of a camera lens to expose film or the like.
-Exposure- The act of presenting a photosensitive surface to rays of light.
-Depth of field- The range of distances along the axis of an optical instrument, usually a camera lens, through which an object will produce a relatively distinct image.
-F-stop- The setting of an adjustable lens aperture, as indicated by an f number.
-Focal length- The distance from a focal point of a lens or mirror to the corresponding principal plane; the distance between an object lens and its corresponding focal plane in a telescope.