ISO 5-1:2009 写真とグラフィック技術—密度測定—パート1：幾何学と関数表記 | ページ 6

3.1

absolute reference reflected flux

Φ_rA

radiant flux that would be reflected by a perfect reflecting diffuser

3.2

absolute reference transmitted flux

Φ_ta

radiant flux that would be transmitted by a perfect transmitting diffuser

3.3

anormal angle

θ

angle between the normal of the reference plane and a direction

Note 1 to entry: Adapted from ASTM E1767.

3.4

azimuthal angle

η

angle between the x-axis of the reference plane and the projection of a direction onto the reference plane

Note 1 to entry: Adapted from ASTM E284.

3.5

cone half-angle

κ

angle between the central axis and the edge of the pupil with the apex at the centre of the sampling aperture

3.6

efflux

radiant flux collected by the receiver from the reference plane

Note 1 to entry: Adapted from ASTM E1767.

3.7

illuminator axis

central axis of the illuminator, usually the optical axis

3.8

illuminator region

intersection of the illuminator beam with the reference plane

3.9

incident flux

Φ_i

radiant flux incident upon the sampling aperture

3.10

influx

radiant flux projected by the illuminator onto the reference plane

Note 1 to entry: Adapted from ASTM E1767.

3.11

influx spectrum

S

spectral distribution of the radiometric quantity, such as radiance, irradiance or radiant flux, incident upon the sampling aperture

Note 1 to entry: This is a function of the source and optics used for the illumination.

3.12

ISO 5 standard density

density value obtained using an instrument conforming to one of the geometries specified in ISO 5-2 or ISO 5-4, and one of the spectral definitions in ISO 5-3

3.13

receiver axis

central axis of the receiver, usually the optical axis

3.14

receiver region

intersection of the receiver beam with the reference plane

3.15

reflectance

ρ

ratio of the reflected flux to the incident flux under specified geometrical and spectral conditions of measurement

Note 1 to entry: Adapted from ASTM E284.

3.16

reflectance density

D_ρ

negative logarithm to the base 10 of the reflectance

3.17

reflectance factor

R

ratio of the reflected flux to the absolute reference reflected flux under the same geometrical and spectral conditions of measurement

3.18

reflected flux

Φ_r

radiant flux that emerges from the specimen surface on which the incident flux falls

3.19

reflection density

D_R

negative logarithm to the base 10 of the reflectance factor

Note 1 to entry: The International Commission on Illumination (CIE) designates the measurement referred to as “reflection density” in ISO 5 as “reflectance factor density”. (See IEC 60050-845:1987|CIE 17.4:1987.)

3.20

spectral responsivity

s

output signal of a receiver per unit input of radiant flux as a function of wavelength

Note 1 to entry: Adapted from ASTM E284.

3.21

transmission density

D_T

negative logarithm to the base 10 of the transmittance factor

3.22

transmittance

τ

ratio of the transmitted flux to the incident flux under specified geometrical and spectral conditions of measurement

Note 1 to entry: In practical instruments for transmittance measurements, the incident flux is defined by the combination of all of the components that are placed before the reference plane (influx), so the incident flux is provided by the surface of the opal diffuser for diffuse transmittance and by the film gate for projection density.

Note 2 to entry: Adapted from ASTM E284.

3.23

transmittance density

D_τ

negative logarithm to the base 10 of the transmittance

Note 1 to entry: The subscript is the lower case Greek letter tau.

3.24

transmittance factor

T

ratio of the transmitted flux to the absolute reference transmitted flux under the same geometrical and spectral conditions of measurement

Note 1 to entry: Adapted from ASTM E284.

3.25

transmitted flux

Φ_t

radiant flux that passes through the specimen and emerges from a surface other than that on which the incident flux falls