UV transmission of sunglasses
Physikfan, Sat Feb 03 2018, 08:05AMThe spectra are photos of Hg spectra with constant exposure time of 1/60 s, light source is a Hg high-pressure lamp, the entrance slit is imaged with a quartz lens via a reflection grating on a screen, to detect the UV lines, the left part of the screen is coated with an ultraviolet luminous color.
The first picture is the Hg reference spectrum, the lines go deep into the UV.
The second picture shows the Hg spectrum, filtered by cheap sunglasses.
The color of the blue line in the spectrum of the sunglasses also corresponds to the color of the visual impression with unarmed eye.
The color of the violet line in the Hg reflectance spectrum does NOT match the color of the visual impression with unarmed eye, and is an artifact, probably due to overexposure at this point.
To my surprise, the quality of the sunglasses is excellent in terms of UV protection,
I will now use these glasses as goggles for my further UV experiments.
UV experiments with normal glasses are in preparation.
Re: UV transmission of sunglasses
2Spoons, Sat Feb 03 2018, 09:42AM
"The color of the violet line in the Hg reflectance spectrum does NOT match the color of the visual impression with unarmed eye, and is an artifact, probably due to overexposure at this point."
Why would you assume its an artifact, just because a camera sees a different color to your eye? It looks like the 436nm line to me.
I would check again with a longer exposure to make sure everything shorter than 400nm really is gone. It should be, the UV filter is a cheap additive for clear plastics.
http://zeiss-campus.magnet.fsu.edu/articles/lightsources/mercuryarc.html
2Spoons, Sat Feb 03 2018, 09:42AM
"The color of the violet line in the Hg reflectance spectrum does NOT match the color of the visual impression with unarmed eye, and is an artifact, probably due to overexposure at this point."
Why would you assume its an artifact, just because a camera sees a different color to your eye? It looks like the 436nm line to me.
I would check again with a longer exposure to make sure everything shorter than 400nm really is gone. It should be, the UV filter is a cheap additive for clear plastics.
http://zeiss-campus.magnet.fsu.edu/articles/lightsources/mercuryarc.html
Re: UV transmission of sunglasses
Physikfan, Tue Feb 06 2018, 08:37PM
Here are the glasses:
Physikfan, Tue Feb 06 2018, 08:37PM
Here are the glasses:
Re: UV transmission of sunglasses
Physikfan, Tue Feb 06 2018, 08:40PM
Hi 2Spoons
Reference spectrum:
The camera is a Canon 10D, exposure time = 1/10 second, f/13, f = 105 mm, ISO 3200.
Hg spectrum with sunglass absorptance:
The camera is a Canon 10D, exposure time = 1 second, f/13, f = 105 mm, ISO 3200.
Physikfan, Tue Feb 06 2018, 08:40PM
Hi 2Spoons
Reference spectrum:
The camera is a Canon 10D, exposure time = 1/10 second, f/13, f = 105 mm, ISO 3200.
Hg spectrum with sunglass absorptance:
The camera is a Canon 10D, exposure time = 1 second, f/13, f = 105 mm, ISO 3200.
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