Abstract: A lighting device is provided with an illumination unit including two or less LED light sources. The illumination unit uses the two or less LED light sources to emit light of a short wavelength band and light of a long wavelength band. An output varying unit functions to vary an output of at least the long wavelength band light. When the output varying unit receives a varying signal, the output varying unit functions to decrease the output of at least the long wavelength band light.

Abstract: A lighting device includes a first light source having a first S/P ratio, a second light source having a second S/P ratio that is higher than the first S/P ratio, and a controller configured to performing dimming control of light output from the first and second light sources. The controller performs the dimming control separately on the first and second light sources at least under a snow covered condition.

Abstract: A lighting device includes first and second light emission units. The first light emission unit emits light having a relatively low color temperature and a high feeling of contrast index. The second light emission unit emits light having a relatively high S/P ratio, which is the ratio of scotopic luminance to photopic luminance. The first light emission unit illuminates a region located at a vertical upper side of a region illuminated by the second light emission unit.

Abstract: A lighting device is provided with an illumination unit including two or less LED light sources. The illumination unit uses the two or less LED light sources to emit light of a short wavelength band and light of a long wavelength band. An output varying unit functions to vary an output of at least the long wavelength band light. When the output varying unit receives a varying signal, the output varying unit functions to decrease the output of at least the long wavelength band light.

Abstract: A lighting device includes a first light source having a first S/P ratio, a second light source having a second S/P ratio that is higher than the first S/P ratio, and a controller configured to performing dimming control of light output from the first and second light sources. The controller performs the dimming control separately on the first and second light sources at least under a snow covered condition.

Abstract: A lighting device includes first and second light emission units. The first light emission unit emits light having a relatively low color temperature and a high feeling of contrast index. The second light emission unit emits light having a relatively high S/P ratio, which is the ratio of scotopic luminance to photopic luminance. The first light emission unit illuminates a region located at a vertical upper side of a region illuminated by the second light emission unit.

Abstract: In a photometry device, photopic vision luminance Lp is measured by a first luminance measuring unit including a first light filter 4 and a first photoelectric converter 5, and scotopic vision luminance Ls is measured by a second luminance measuring unit including a second light filter 6 and a second photoelectric converter 7. A calculation part 8 calculates mesopic vision luminance Lmes based on a measurement value (photopic vision luminance Lp) of the first luminance measuring unit and a ratio of a measurement value (scotopic vision luminance Ls) of the second luminance measuring unit to the measurement value (photopic vision luminance Lp) of the first luminance measuring unit. Consequently, the photometry device can improve measurement accuracy of the brightness (mesopic vision luminance) in mesopic vision.

Abstract: In a photometry device, photopic vision luminance Lp is measured by a first luminance measuring unit including a first light filter 4 and a first photoelectric converter 5, and scotopic vision luminance Ls is measured by a second luminance measuring unit including a second light filter 6 and a second photoelectric converter 7. A calculation part 8 calculates mesopic vision luminance Lmes based on a measurement value (photopic vision luminance Lp) of the first luminance measuring unit and a ratio of a measurement value (scotopic vision luminance Ls) of the second luminance measuring unit to the measurement value (photopic vision luminance Lp) of the first luminance measuring unit. Consequently, the photometry device can improve measurement accuracy of the brightness (mesopic vision luminance) in mesopic vision.