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Composite spectra of CMH & other lamps
Composite to identify the new CMH lamps. Self descritptive.
Keywords: Lamps

Composite spectra of CMH & other lamps

Composite to identify the new CMH lamps. Self descritptive.

Metal-Halide_2types.jpg MV(DX)_spectra.jpg Metal-Halide_lamps_compared.jpg NewLights_composite(labels).jpg IMG_1071.jpg
File information
Filename:NewLights_composite(labels).jpg
Album name:lights*plus / Lamp Spectra
Keywords:Lamps
Filesize:272 KiB
Date added:Dec 10, 2011
Dimensions:2400 x 1200 pixels
Displayed:135 times
URL:http://www.galleryoflights.org/mb/gallery/displayimage.php?pid=9856
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Comment 1 to 6 of 6
Page: 1

dor123   [Dec 10, 2011 at 07:40 PM]
Most CMH lamps have the following halide (Apart from mercury): Sodium, Thallium, Dysprosium, Holmium and thullium.
In the spectrum of the CMH, the wide green line right to the mercury green line is of thallium, and like the sodium D line, the thallium green line also shows boardening and self absorbing.
Self absorbing of the green thallium line, and also the two blue and violet indium lines (Not included in CMH lamps) can be seen in the european Osram Powerstart HQI-TD and HQI-T compact MH lamps, and in overdosed green and blue MH lamps.
lights*plus   [Dec 10, 2011 at 07:55 PM]
Strong Indium lines are found at 451nm and at 410nm. Most of the stock digital cameras don't pick up the violet area of the spectrum very well, (this includes the 405nm Hg line) so you need to buy a modified camera, modify it yourself, or use a film camera. Film records this area nicely. Black & white film also records the 365nm area (Hg complex)..in the ultraviolet!
dor123   [Dec 10, 2011 at 07:58 PM]
In CMH lamps, there is no indium. The blue line that you see at 410nm, is probably of the rare-earths.
Digital cameras can see UVA light as well as IR light.
My camera can see blacklight fluorescent and UV LEDs much brighter than they are anyway.
Silverliner14B   [Dec 10, 2011 at 08:02 PM]
Very interesting pic, thanks for sharing with us!
lights*plus   [Dec 10, 2011 at 08:12 PM]
@dor123 Yes there's no indium in the spectra above. And, CMOS chips that are inside all digital cameras are sensitive to a wide portion of the spectrum from the violet to the far IR. The stock filter in front of the chip, that which is always found in most off-the-shelf digital cameras, restricts what can be recorded from 420nm to 635nm... For our purposes, this is a bit constrictive.
dor123   [Dec 13, 2011 at 11:12 AM]
A correction for my former comment: The 410nm line is mercury, not rare-earths. the mercury have two blue lines: a blue one and a violet one which is less notable with the unaided eye.

Comment 1 to 6 of 6
Page: 1