Daylight
Smith, Harry. 1982. Light Quality, Photoperception, and Plant Strategy. Annual Review of Plant Physiology 33 481–518.
Spectrum 81: 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
4/Mar/2010 ; updated:
Sarina Wunderlich
9/Oct/2011
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 - 800 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 | ( 0.34 ; 0.35 ) | ( 0.51 ; 0.42 ) | ( 0.34 ; 0.34 ; 0.28 ) |
| CCT | 5300 Kelvin | 3700 Kelvin | 4300 Kelvin |
| distance | 0.094 | 0.076 | |
| 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) 39000 µW/cm² = 390 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) 39000 µW/cm² = 390 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) 21300 µW/cm² = 213 W/m² VIS Rep4 ( 350 nm - 700 nm) 31500 µW/cm² = 315 W/m² purple ( 380 nm - 420 nm) 1500 µW/cm² = 15 W/m² VIS ( 380 nm - 780 nm) 37500 µW/cm² = 375 W/m² VIS2 ( 400 nm - 680 nm) 29700 µW/cm² = 297 W/m² PAR ( 400 nm - 700 nm) 31500 µW/cm² = 315 W/m² tmp ( 400 nm - 1100 nm) 39000 µW/cm² = 390 W/m² blue ( 420 nm - 490 nm) 7120 µW/cm² = 71.2 W/m² green ( 490 nm - 575 nm) 9830 µW/cm² = 98.3 W/m² yellow ( 575 nm - 585 nm) 1140 µW/cm² = 11.4 W/m² orange ( 585 nm - 650 nm) 7090 µW/cm² = 70.9 W/m² red ( 650 nm - 780 nm) 10900 µW/cm² = 109 W/m² IRA ( 700 nm - 1400 nm) 7540 µW/cm² = 75.4 W/m² IR2 ( 720 nm - 1100 nm) 5810 µW/cm² = 58.1 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 22100 µW/cm² Luminosity 87700 lx Human L-Cone 13100 µW/cm² Human M-Cone 10900 µW/cm² Human S-Cone 5750 µW/cm² CIE X 11700 µW/cm² CIE Y 12200 µW/cm² CIE Z 10700 µW/cm² PAR 149000000 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 11300 µW/cm² M-Cone 11300 µW/cm² S-Cone 9160 µW/cm² U-Cone 1560 µW/cm² UVR - ICNIRP 2004 0 Rel Biol Eff Melatonin Supression 8960 µW/cm² Blue Light Hazard 6540 µW/cm² (74.6 µW/cm² per 1000 lx) CIE 174:2006 PreVit D3 0 µW/cm² Lumen Reptil 82100 "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 88700 lx Solarmeter 6.4 (D3) 0 IU/min UVX-31 0 µW/cm² IL UVB 0 µW/cm² IL UVA 0 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.) 455 W/m² Solarmeter 4.0 (UVA) 1.13 mW/cm² LS122 (manuf.) 0 W/m² ISM400 (first guess) 382 W/m² LS122 (assumption) 17.7 W/m² ISM400_new 342 W/m² Solarmeter 10.0 (Global Power) (assumption) 451 W/m²