1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Night vision

  1. Jan 10, 2010 #1
    isn't the frequency that is reflected back to a night vision device by a source at night correspond to a particular color? Which can then be converted back to its original color?
     
  2. jcsd
  3. Jan 10, 2010 #2

    Danger

    User Avatar
    Gold Member

    Welcome to PF, Rajeshmarndi.
    There are a lot of night vision devices, including several generations each of IR and Starlight. They don't all operate the same way.
    Starlights amplify ambient light, and I don't really know anything else about them.
    IR units operate through infrared emission ('passive') or reflection ('active'), which means that the 'translation' is a B&W signal. That usually comes out as a particular colour gradient which depends upon the interpretation circuitry and visual display characteristics.
     
  4. Jan 10, 2010 #3

    russ_watters

    User Avatar

    Staff: Mentor

    Color photos are generated by using monochrome (black and white) sensors with alternating color filters and having software sort out which pixel is which color. Removing the filters and shooting everything monochrome increases the signal to noise ratio because you aren't blocking any of the signal with a filter.

    So with a "starlight" device, black and white will mean higher sensitivity.

    And just in case the IR part wasn't clear - for an IR device, there is no visual range color being detected so nothing to translate to accurate color.
     
  5. Jan 10, 2010 #4

    rcgldr

    User Avatar
    Homework Helper

  6. Jan 10, 2010 #5
    Low light color cameras do exist as well:

    Using image intensifier ("standard" night vision technology):
    http://www.copst.com/media/filebank/org/F04-001-D01-B%20Lunavision%20Datasheet.pdf [Broken]
    http://www.laseroptronix.se/cam/CCD%20Niviscameras.pdf [Broken]

    Using high gain CCD:
    http://www.toshiba.com/taisisd/indmed/products/pdf/ik1000me.pdf
     
    Last edited by a moderator: May 4, 2017
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook