World Library  
Flag as Inappropriate
Email this Article

Hot mirror

Article Id: WHEBN0001925184
Reproduction Date:

Title: Hot mirror  
Author: World Heritage Encyclopedia
Language: English
Subject: Mirror, Photographic filter, Cold mirror, Dielectric mirror, Indium tin oxide
Collection: Mirrors, Optics
Publisher: World Heritage Encyclopedia

Hot mirror

A Tiffen photographic hot mirror filter.

A hot mirror is a specialized dielectric mirror, a dichroic filter, often employed to protect optical systems by reflecting infrared light back into a light source, while allowing visible light to pass. Hot mirrors can be designed to be inserted into the optical system at an incidence angle varying between zero and 45 degrees, and are useful in a variety of applications where heat build-up can damage components or adversely affect spectral characteristics of the illumination source. Wavelengths reflected by an infrared hot mirror range from about 750 to 1250 nanometers. By transmitting visible light wavelengths while reflecting infrared, hot mirrors can also serve as dichromatic beam splitters for specialized applications in fluorescence microscopy or optical eye tracking.

Some early digital cameras designed for visible light capture, such as the Associated Press NC2000 and Nikon Coolpix 950, were unusually sensitive to infrared radiation, and tended to produce colours that were contaminated with infrared. This was particularly problematic with scenes that contained strong sources of infrared, such as fires, although the effect could be moderated by inserting a photographic hot mirror filter into the imaging pathway.[1] Conversely, these cameras could be used for infrared photography by inserting a cold mirror filter into the imaging pathway, most commonly by mounting the filter on the front of the lens.[2]

New incandescent bulbs incorporate hot mirrors, increasing efficiency by redirecting unwanted infrared frequencies back to the filament.[3][4]


  1. ^ "A look back at the NC2000", Eamon Hickey, January 2005
  2. ^ Infrared Photography by Thom Hogan
  3. ^ "Heat Mirror For Incandescent Lamp - Patent 4346324". 
  4. ^ "A cool light bulb". 

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.