[Wet Thumb Forum]-Spectra of fluorescent tubes.

[gsmollin]

I got interested in seeing the spectra of the lighting over my aquarium... I guess I'm just a gearhead. Anyway, I found an inexpensive spectrometer, the Starlab PS-14/Plastic, available here: http://www.starlab.com/psprod.html . With this inexpensive device, I have been able to peruse the spectra of the fluorescent tubes I am using. It's been fun, and I have taken a few pix of the spectra.

A word about the pix- the camera does not respond the same as the human eye. I don't know which is more accurate, although I know the eye is more sensitive, and has a much greater dynamic range. The colors do not look the same, particularly the weak, continuous spectrum behind the three prominant lines.

For reference, here is the spectrum of the sun:



This was taken through a translucent window, which added the horizontal dark lines. The sun is really hard to get well, without the right solar filter. My telescope solar filter was too dark. Maybe the .96 ND filter will work. Anyway, this is pretty representative of a solar spectrum.

The next pic is the old/new tubes I posted about last week:



The one marked "96 W" is new, and the one marked "Panasonic" is 10,000 hours old. It has a definitely stronger red, and weaker green, and a prominent yellow section. Sadly, the camera does not record the yellow spectrum well. Also, these spectra are slightly out-of-focus, as I focused the camera on the scale, and the spectrum appears in front of the scale. There are some fine lines visible that do not show in the pix.

Well, I may fool with this some more, and post a few other lamp spectra, since I have a new toy to play with.

[gsmollin]

I got interested in seeing the spectra of the lighting over my aquarium... I guess I'm just a gearhead. Anyway, I found an inexpensive spectrometer, the Starlab PS-14/Plastic, available here: http://www.starlab.com/psprod.html . With this inexpensive device, I have been able to peruse the spectra of the fluorescent tubes I am using. It's been fun, and I have taken a few pix of the spectra.

A word about the pix- the camera does not respond the same as the human eye. I don't know which is more accurate, although I know the eye is more sensitive, and has a much greater dynamic range. The colors do not look the same, particularly the weak, continuous spectrum behind the three prominant lines.

For reference, here is the spectrum of the sun:



This was taken through a translucent window, which added the horizontal dark lines. The sun is really hard to get well, without the right solar filter. My telescope solar filter was too dark. Maybe the .96 ND filter will work. Anyway, this is pretty representative of a solar spectrum.

The next pic is the old/new tubes I posted about last week:



The one marked "96 W" is new, and the one marked "Panasonic" is 10,000 hours old. It has a definitely stronger red, and weaker green, and a prominent yellow section. Sadly, the camera does not record the yellow spectrum well. Also, these spectra are slightly out-of-focus, as I focused the camera on the scale, and the spectrum appears in front of the scale. There are some fine lines visible that do not show in the pix.

Well, I may fool with this some more, and post a few other lamp spectra, since I have a new toy to play with.

[gsmollin]

A word about the fluorescent spectra:
Mercury lines appear at 405 nm, 436 nm, 546 nm, 577 nm and 579 nm. These lines appear in every fluorescent tube I've looked at. The real differences occur at other colors, especially below 580 nm.