key word | short description | paragraph + hyperlink |
sb |
Stilb, seldom used unit for Luminance L; = 1 cd/cm^2 |
table 8.2.1 in 8. Comparison Tables |
scanning process | shifts the measurement aperture in matrix form | 4.2.4 Radiance L |
scanning spectroradiometer | spectroradiometer that measures one band after another | 4.4.2 Instruments (for spectral. resolv. meas.) |
scared (of light measurement) | uncomfortable task | 1. Goals of this Essay |
scatter | irregular and stochastic reflection | 7.2 Coherence (of Laser Radiation) |
sensitivity | here: factor between meter reading and optical power | 7.3 Power Range (of Laser Radiation) |
sensitivity calibration | same as amplitude calibration | 4.4.2 Instruments (for spectral. resolv. meas.) |
sensor | transducer for light signal --> electrical signal | 4.1.1 Radiant Flux (Phi) |
skew | see "tilt" | 4.3.3 Cosine Correction |
slit function | response of monochromator tuned across single line spectrum | 4.4.2 Instruments (for spectral. resolv. meas.) |
solid angle (Omega) | stereoscopic analogy to plane angles | 4.2.2 Solid Angle (Omega) |
solid angle (Omega) | stereoscopic analogy to plane angles | 4.2.3 Radiant Intensity I |
source size limit | allowable maximim size for treating like point source | 6.1 Point Source and Distance |
source's structure | local variations of light emitting properties | 5.2.3 Luminance L |
spatial distribution | how some property is locally structured | 5.2.3 Luminance L |
spatial flux density | (luminous flux per receiving area:) | 5.3.1 Illuminance E |
spatial flux density | flux per area of bundle cross-section | 4.3.1 Irradiance E |
spatially resolved | showing how a value is depending upon angle, displacement,... | 4.2.1 Radiant Exitance M |
speckles | stochastic interference pattern | 7.2 Coherence (of Laser Radiation) |
spectral luminous efficiency | relative human eye spectral sensitivity characteristics V[(lambda)] |
4.4.3-Example 5.0 Photometry, general |
spectral resolution |
here: replacing one broad-band measurement by many narrow-band ones |
4.4.1 Why use Spectral Resolution? |
spectroradiometer | measuring radiometric units on a by-wavelength basis | 4.4.2 Instruments (for spectral. resolv. meas.) |
spectrum information |
vector of successive wavelenghts, associated with a vector of spectral values |
4.4.3 Applying Spectral Resolution |
spike and notch | discontinuities in e.g. spectral characteristics | 4.4.3 Applying Spectral Resolution |
sr | steradian, pseudo-unit for solid angle (Omega) | 4.2.2 Solid Angle (Omega) |
standard candle | precursor of SI-unit 'candela' | 5.0 Photometry, General |
standard meter | object for calibrating all meter rules | 2. Introduction |
steradian | pseudo-unit for solid angle (Omega) | 4.2.2 Solid Angle (Omega) |
Stilb |
seldom used unit for Luminance L = 1 cd/cm^2 |
table 8.2.1 in 8. Comparison Tables |
stray light (monochromator) | performance parameter of monochromator | 4.4.2 Instruments (for spectral. resolv. meas.) |
structured light source | source with lighter and darker portions | 4.2.1 Radiant Exitance M |
structured light source | source with lighter and darker portions | 4.2.4 Radiance L |
substitute instrumentation | instrument that is usable though not specialized for the task | 4.3.1 Irradiance E |
substitute instrumentation | instrument that is usable though not specialized for the task | 4.3.2 Radiant Exposure H |
substitute instrumentation | instrument that is usable though not specialized for the task | 5.3.2 Exposure H |
table of spectral values | table form of spectral characteristics curve | 4.4.3-Example |
Talbot | seldom used unit for Exposure H | 5.3.2 Exposure H |
tilt | a plane's deviation from position normal to light ray | 4.3.3 Cosine Correction |
topics of the essay | the facts it describes and the results it strives for | 1. Goals of this Essay |
transform radio-/photometry | by weighting and integrating spectral characteristics | 5.0 Photometry, General |
transient light | light that varies fast, but only once | 5.1.2 Luminous Energy Q |
transient radiation | radiation that varies fast, but only once | 4.1.2 Radiant Energy Q |
tubular incandescent lamp | lamp with filament in cylindrical tube | 6.2 Line Source and Distance |
ulbricht sphere | = integrating sphere | 4.2.1 Radiant Exitance M |
underfilled aperture | bundle cross-sectional figure smaller than detector aperture | 4.1.1 Radiant Flux (Phi) |
underfilled aperture | bundle cross-sectional figure smaller than detector aperture | 5.1.1 Luminous Flux (Phi) |
unit | quantities consist of numeric value times unit name | 8. Comparison Tables |
usual error | error of normal radiometers | 4.2.4 Radiance L |
V(lambda) | = spectral luminous efficiency (eye spectral sensitivity) |
4.4.3-Example 5.0 Photometry, general |
V(lambda)-corrected detector | detector that spectrally emulates the human eye | 7.1 Monochromatism (of Laser Radiation) |
W | Watt, SI unit for radiant flux | 2. Introduction |
W | Watt, SI unit for radiant flux | 4.1.1 Radiant Flux (Phi) |
W | Watt, SI unit for radiant flux |
table 8.1 in 8. Comparison Tables |
W/sr | = Watt per Steradian, SI unit of radiant intensity | 4.2.3 Radiant Intensity I |
Watt | SI unit for radiant flux | 2. Introduction |
Watt | SI unit for radiant flux | 4.1.1 Radiant Flux (Phi) |
Watt | SI unit for radiant flux |
table 8.1 in 8. Comparison Tables |
Watt per square-meter | SI unit for radiant exitance and for irradiance | 4.2.1 Radiant Exitance M |
Watt per square-meter | SI unit for radiant exitance and for irradiance | 4.3.1 Irradiance E |
Watt per Steradian | SI unit for radiant intensity I | 4.2.3 Radiant Intensity I |
Watt-Second | SI unit for radiant energy | 4.1.2 Radiant Energy Q |
wavelength | distance between points of equal phase in a wave | 3. What is Light |
wavelength calibration | comparing spectroradiometer to wavelength standards | 4.4.2 Instruments (for spectral. resolv. meas.) |
wavelength limit | spectral limit of measurement | 4.0 Radiometry/General |
wavelength limits | spectral limits of measurement | 4.4.1 Why use Spectral Resolution? |
wavelength resolution | discerning small wavelength differences | 4.4.2 Instruments (for spectral. resolv. meas.) |
waving figure | stereoscopically formed by a line which is pinned down to one point | 4.2.2 Solid Angle (Omega) |
weighting | multiply e.g. spectr. characteristics of source with those of filter | 4.4.3 Applying Spectral Resolution |
weighting | multiply e.g. spectr. characteristics of source with those of filter | 4.4.3-Example |
white frame | entire frame signal, collected in uniform illumination | 4.2.4 Radiance L |
wide solid angle | here: light incident from a wide range of angles | 4.3.3 Cosine Correction |
wide-spread use (of illuminance meters) | enhancing availability of illuminance meters | 5.3.1 Illuminance E |