PhotoNotes site navigation. About. Dictionary. Articles. Reviews. LOOKUP | FORUM | DONATIONS

 

The PhotoNotes.org Dictionary of Film and Digital Photography.

-----


T-stop.

Some lenses, mainly those used in motion cinematography and not still photography, have apertures rated in T-stops. T-stops indicate the actual or absolute amount of light being passed through (transmitted) the aperture diaphragm. They differ therefore from f-stops, which indicate the aperture size relative to the focal length. (in a sense, T-stops are absolute and f-stops are relative)

T-stops can be an important concept with certain zoom lenses in particular, since zooms tend to result in some light loss, though this is not a huge issue for most modern multicoated lenses. Lenses with T-stop markings usually have the f-stops marked in white and the T-stops in red.

cf. aperture, f stop, transmittance.

Entry last updated 2002-05-09. Term 1253 of 1487.


Previous term: T*.

Next term: TTL.

 


-----

This document is copyright © 2002-2014 NK Guy, PhotoNotes.org. This information is provided with neither warranties nor claims of accuracy or completeness of any sort. Use this information at your own risk. All trademarks mentioned herein belong to their respective owners.

You may copy and print this document for your own personal use. You may not, however, reprint or republish this work, in whole or in part, without prior permission from me, the author. Such republication includes inclusion of this work in other Web sites, Web pages, FTP archives, books, magazines or other periodicals, CD-ROM and DVD-ROM compilations or any other form of publication or distribution. Please do not frame this site within another.

Please send comments or error reports using the feedback form.

-----