Vintage Lighting dichroic Invention

ship

Senior Team Emeritus
Premium Member
Joined
Mar 29, 2003
Location
Illinois
Went up to the attic, Found the book but not John Carter's old GE catalogues in need of future looking for I believe 1970's date.

Part 198 - Mechnical and Acoustical Coordination; "Selective Control of Radiant Energy." P. 203 Architectural Lighting Graphics, John E. Flynn Van Nostrand, NY. 1962.

If you can find a copy of this book.... It is in my top ten of all books read.

Concept of "Interference Filters", with other notations on the concept.

- Interference Filters: These filters are sometimes called "Dichrolic" and provide selective transmission of radiant energy. They are generally used to transmit light and reflect the invisible radiation.' Infra-red in the beam is minimized (up to 85% reduction) with no sigificant loss of light. Re-directed radiant energy is diflected to a heat-absorbing collecting surface which must be cooled by more conventional air or water techniques.

A constant joke with Mark from Osram I play, is water cooled halogen lamp invention given some xenon lamps have them. This might be the source of the joke, but also shows that dichroic technology started years before I was born.
 

Attachments

Last edited:

RonHebbard

Well-Known Member
Premium Member
Joined
Jun 12, 2004
Location
Waterdown, ON, CA
Went up to the attic, Found the book but not John Carter's old GE catalogues in need of future looking for I believe 1970's date.

Part 198 - Mechnical and Acoustical Coordination; "Selective Control of Radiant Energy." P. 203 Architectural Lighting Graphics, John E. Flynn Van Nostrand, NY. 1962.

If you can find a copy of this book.... It is in my top ten of all books read.

Concept of "Interference Filters", with other notations on the concept.

- Interference Filters: These filters are sometimes called "Dichrolic" and provide selective transmission of radiant energy. They are generally used to transmit light and reflect the invisible radiation.' Infra-red in the beam is minimized (up to 85% reduction) with no sigificant loss of light. Re-directed radiant energy is diflected to a heat-absorbing collecting surface which must be cooled by more conventional air or water techniques.

A constant joke with Mark from Osram I play, is water cooled halogen lamp invention given some xenon lamps have them. This might be the source of the joke, but also shows that dichroic technology started years before I was born.

@ship Are you suggesting God invented light before you were born??
Toodleoo!
Ron Hebbard
 

JonCarter

Well-Known Member
Joined
Apr 18, 2011
Location
Meridian, Idaho, US
We had a dozen or so dichroic filters--big things, about 10" square--which we used on our Q-I instruments when we needed them for daylight fills on exterior shots. Cameras were filtered (85B) for shooting in daylight. Lotsa heat from those guys--hard on the instruments. I'd rather use the reflectors but couldn't always.
 

ship

Senior Team Emeritus
Premium Member
Joined
Mar 29, 2003
Location
Illinois
god invented light(s) in amazing ways. The study of the Preveir PC, questions about the invention of the Fresnel, the Pat 73 and lots of other questions about the past for me. Less about god, than history. And that by the 60's dichroics as with halogen lamps were invented. Just took to make them into something useful for the stage. Lots of history about how the dual ended halogen lamp became the modern lamp. Dichroics of the same period took longer but have history as posted about earlier in important.l
 

RonaldBeal

Well-Known Member
Joined
Jan 24, 2004
Location
TN
Dichroics were used by NASA for lunar cameras: http://www.hawestv.com/mtv_FAQ/FAQ_moon_5.htm and https://www.hq.nasa.gov/alsj/Niemyer-Paper.pdf
The mission control displays were not video, but electromechanical devices that used dichroics for color: https://hackaday.com/2020/10/29/a-l...at-mission-control-in-the-golden-age-of-nasa/

And the "gold" visor on lunar EVA helmets is part of a dichroic filter that reduces UV and IR so the Astronauts didn't get sunburned. (can't find the reference at the moment)
 
  • Like
Reactions: RonHebbard

coolsvens

Active Member
Joined
May 19, 2012
Location
A, A
For those interested in more Dichroic knowledge High End Systems in Austin, TX developed their own chambers and make Dichorics. More about that process here, it's incredibly fascinating.

 

RonaldBeal

Well-Known Member
Joined
Jan 24, 2004
Location
TN
If I recall correctly, most modern dichroics use layers of chromium oxide and titanium oxide, vacuum deposited as the layers. the 2 metals (hence di-chroic) act as a bandpass filter, where one metal is the low pass filter and the other is the high pass filter. (and I no longer recall which is which.) The density, and number of layers determine the cutoff frequencies and saturation.
Caveat, this is from my recollection of the state of the art in the late 1900's... things may have changed since then!
 
  • Like
Reactions: RonHebbard

Users who are viewing this thread