Small Gaps
JOHN A. ENDLER. 1993. The Color of Light in Forests and Its Implications. Ecological Monographs 63.1. 1–27.
Spectrum 462: SUN Edit
DeleteMeasurement
| Brand |
other other |
|---|---|
| Lamp Product |
Sun Direct sunlight |
| Lamp ID |
SUN (01/2000) |
| Spectrometer | - |
| Ballast | - no ballast or default/unknown ballast - |
| Reflector | |
| Distance | 0 cm |
| Age | 0 hours |
| Originator (measurement) | Publication |
Database entry created:
Sarina Wunderlich
24/Jan/2012 ; updated:
Sarina Wunderlich
24/Jan/2012
Colorimetry
Colorimetry is the science to describe physically the human color perception. The wavelength range 380 nm - 780 nm is visible to humans and detected by three different photoreceptors. Many Reptiles see the range 350 nm - 800 nm and have an additional UV photoreceptor in their retina.
WARNING: The measurement range (350 - 800 nm) is not sufficient for this evaluation! Data is only available in the range 400 - 700 nm. Results are shown anyway but should be ignored by anyone except experts.
Whereas a spectrometer measures the intensity in every tiny wavelength interval resulting in thousands of individual intensities, the human eye only measures three intensities detected by the three cones. The same is true for the reptile eye with usually three or four photoreceptors. Effectively the detailled spectrum displayed above reduces to a much compacter bar graph displayed below. The photoreceptor sensitivites from these L-Cone, M-Cone, S-Cone, and U-Cone are used, they are chosen as an average of measured reptile photoreceptor sensitivity curves. The bar graph also shows as reference the intensity seen by the three or four photoreceptors for average sunlight (id 1).
From these three numbers the colour coordinate and the correlated colour temperature for humans are calculated using the CIE standard method. I adapted this concept to a "3 cone reptile (M,S,U)" and a "4 cone reptile (L,M,S,U)". I am sure, that this adaption to other colour spaces makes sense mathematically and this is also done in scientific research regarding colour vision of animals, however I have not seen calculation of colour temperatures for other animals in the scientific literature. Even if it is hypothetical, at least this shows, how arbitrary the colour temperature is, and that the colour temperature calculated for humans does not apply to reptiles. The colour spaces also show the colour coordinates of different phases of daylight ((ids 1, 338 – 451, 511 – 513 ), indicated by crosses, coloured in the appriximate colour perceived by a human.
| Human (CIE) | 3 cone reptile | 4 cone reptile | |
|---|---|---|---|
| Cone Excitation | |||
| Colour Coordinate | ( 0.37 ; 0.39 ) | ( 0.59 ; 0.36 ) | ( 0.42 ; 0.34 ; 0.21 ) |
| CCT | 4200 Kelvin | 3100 Kelvin | 3600 Kelvin |
| distance | 0.068 | 0.056 | |
| colour space | 3-D-graph not implemented yet |
Vitamin D3 Analysis
Vitamin D3 is produced by UVB radiation around 300 nm. 7DHC/ProD3 present in the skin is converted to PreD3 when absorbing an UV photon. PreD3 can be converted back to ProD3, to Lumisterol, or to Tachysterol when absorbing another UV photon or can be converted to Vitamin D3 in a warm environment.
This process prevents any overdose of vitamin D3 from UV radiation with a spectrum similar to sunlight. As a comparison the solar spectra at 20°(id:14) and at 85°(id:21) solar angle are shown.
The ratio of the two solarmeters 6.2 (UVB) and 6.5 (UV index) readings has proven a useful and very simply number to acess the spectral shape in the vitamin-d3-active region.
Effective Irradiances
Effective irradiances are calculated for all ranges, actionspectra and radiometers currently present in this database.
The calculation method is a numerical implementation (Simpson's rule) of the formula
To learn more about calculating effective irradiances and radiometers I recommend this excellent report on UVB meters: Characterizing the Performance of Integral Measuring UV-Meters (pdf).
The numbers in the following tables can also be used to estimate certain (effective) irradiances from radiomer readings. Example: If the database lists
- range: UVB (US) = 13.8 µW/cm²
- radiometer: Solarmeter 6.2 = 19.6 µW/cm²
Ranges
total ( 0 nm - 0 nm) 3440 µW/cm² = 34.4 W/m² UVC ( 0 nm - 280 nm) 0 µW/cm² = 0 W/m² non-terrestrial ( 0 nm - 290 nm) 0 µW/cm² = 0 W/m² total2 ( 250 nm - 880 nm) 3440 µW/cm² = 34.4 W/m² UVB (EU) ( 280 nm - 315 nm) 0 µW/cm² = 0 W/m² UVB (US) ( 280 nm - 320 nm) 0 µW/cm² = 0 W/m² UVA+B ( 280 nm - 380 nm) 0 µW/cm² = 0 W/m² Solar UVB ( 290 nm - 315 nm) 0 µW/cm² = 0 W/m² UVA D3 regulating ( 315 nm - 335 nm) 0 µW/cm² = 0 W/m² UVA (EU) ( 315 nm - 380 nm) 0 µW/cm² = 0 W/m² UVA2 (medical definition) ( 320 nm - 340 nm) 0 µW/cm² = 0 W/m² UVA (US) ( 320 nm - 380 nm) 0 µW/cm² = 0 W/m² UVA1 (variant) ( 335 nm - 380 nm) 0 µW/cm² = 0 W/m² UVA1 (medical) ( 340 nm - 400 nm) 0 µW/cm² = 0 W/m² vis. UVA ( 350 nm - 380 nm) 0 µW/cm² = 0 W/m² VIS Rep3 ( 350 nm - 600 nm) 2090 µW/cm² = 20.9 W/m² VIS Rep4 ( 350 nm - 700 nm) 3440 µW/cm² = 34.4 W/m² purple ( 380 nm - 420 nm) 83.3 µW/cm² = 0.833 W/m² VIS ( 380 nm - 780 nm) 3440 µW/cm² = 34.4 W/m² VIS2 ( 400 nm - 680 nm) 3200 µW/cm² = 32 W/m² PAR ( 400 nm - 700 nm) 3440 µW/cm² = 34.4 W/m² tmp ( 400 nm - 1100 nm) 3440 µW/cm² = 34.4 W/m² blue ( 420 nm - 490 nm) 589 µW/cm² = 5.89 W/m² green ( 490 nm - 575 nm) 1070 µW/cm² = 10.7 W/m² yellow ( 575 nm - 585 nm) 146 µW/cm² = 1.46 W/m² orange ( 585 nm - 650 nm) 906 µW/cm² = 9.06 W/m² red ( 650 nm - 780 nm) 643 µW/cm² = 6.43 W/m² IRA ( 700 nm - 1400 nm) 0 µW/cm² = 0 W/m² IR2 ( 720 nm - 1100 nm) 0 µW/cm² = 0 W/m² IRB ( 1400 nm - 3000 nm) 0 µW/cm² = 0 W/m²
Actionspectra
Erythema 0 UV-Index Pyrimidine dimerization of DNA 0 µW/cm² Photoceratitis 0 µW/cm² Photoconjunctivitis 0 µW/cm² DNA Damage 0 Vitamin D3 0 µW/cm² Photosynthesis 2280 µW/cm² Luminosity 10200 lx Human L-Cone 1540 µW/cm² Human M-Cone 1220 µW/cm² Human S-Cone 458 µW/cm² CIE X 1370 µW/cm² CIE Y 1420 µW/cm² CIE Z 879 µW/cm² PAR 16500000 mol photons Extinction preD3 0 e-3*m²/mol Extinction Tachysterol 0 e-3*m²/mol Exctincition PreD3 0 m²/mol Extinction Lumisterol 0 m²/mol Exctincition Tachysterol 0 m²/mol Extinction 7DHC 0 m²/mol L-Cone 1360 µW/cm² M-Cone 1110 µW/cm² S-Cone 688 µW/cm² U-Cone 86.9 µW/cm² UVR - ICNIRP 2004 0 Rel Biol Eff Melatonin Supression 757 µW/cm² Blue Light Hazard 512 µW/cm² (50.4 µW/cm² per 1000 lx) CIE 174:2006 PreVit D3 0 µW/cm² Lumen Reptil 8340 "pseudo-lx" Vitamin D3 Degradation 0 µW/cm² Actinic UV 0 µW/cm² (0 mW/klm) Exctincition Lumisterol 0 m²/mol Exctincition 7DHC 0 m²/mol Exctincition Toxisterols 0 m²/mol
Broadbandmeters
Solarmeter 6.2 (UVB, pre 2010) 0 µW/cm² Solarmeter 6.5 (UV-Index, pre 2010) 0 Leybold UVB 0 µW/cm² Leybold UVA 0 µW/cm² Leybold UVC 0 µW/cm² DeltaOhm UVB 0 µW/cm² DeltaOhm UVC 0 µW/cm² Vernier UVB 0 µW/cm² Vernier UVA 0 µW/cm² Gröbel UVA 0 µW/cm² Gröbel UVB 0 µW/cm² Gröbel UVC 0 µW/cm² Luxmeter 10200 lx Solarmeter 6.4 (D3) 0 IU/min UVX-31 0 µW/cm² IL UVB 0 µW/cm² IL UVA -0.000424 µW/cm² Solarmeter 6.5 (UVI, post 2010) 0 UV-Index Solarmeter 6.2 (UVB, post 2010) 0 µW/cm² (Solarmeter Ratio = NAN) Solarmeter AlGaN 6.5 UVI sensor 0 UV Index GenUV 7.1 UV-Index 0 UV-Index Solarmeter 10.0 (Global Power) (manuf.) 38.7 W/m² Solarmeter 4.0 (UVA) 0.0589 mW/cm² LS122 (manuf.) 0 W/m² ISM400 (first guess) 29.3 W/m² LS122 (assumption) 1.6 W/m² ISM400_new 24.3 W/m² Solarmeter 10.0 (Global Power) (assumption) 38.5 W/m²