What is Luminance Contrast
Luminance contrast is the difference in the amount of light reflected from one surface or component compared to another surface or component. It is a measure of the visual distinction between the object and its background. Luminance contrast is not the difference in color or color contrast, but rather the difference in the light reflective properties of each color.
The calculation of luminance contrast can be expressed as a ratio or fraction, typically using the luminance values of the object and background. The formula for calculating luminance contrast is (L1 – L2)/L1 or (L2 – L1)/L1 = | Δ L/L1 |, where L1 and L2 represent the luminances of the background and the object, respectively. This equation specifies the form of the luminance contrast calculation.
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The ratio Δ L/L1 in the equation is known as Weber’s fraction, which describes the smallest detectable difference in luminance. This helps determine the perceptual sensitivity to changes in brightness. In some cases, when only reflecting surfaces are involved, luminance contrast can be expressed in terms of reflectance. Reflectance refers to the ratio of light reflected by a surface to the incident light falling on it. The contrast formula using reflectance is (ρ1 – ρ2)/ρ1 or (ρ2 – ρ1)/ρ1, where ρ1 and ρ2 represent the reflectances of the background and the object, respectively. The method of computing contrast using reflectance holds true only for perfectly diffusing surfaces. For other surfaces, additional factors such as angles of incidence and view need to be taken into consideration.
Mungkin Anda Tertarik Dengan
- Sensor keterhunian PIR pemasangan di langit-langit dengan output relai kontak kering
- Suplai tegangan rendah 12/24VDC atau 12/24VAC
- Kontak relai terisolasi COM, NO, dan NC untuk input EMS, HVAC, dan kontrol bangunan
- Sakelar sensor gerak gelombang mikro pemasangan tanam di langit-langit bertegangan rendah DC
- Input 12 VDC / 24 VDC dengan rentang 10-30 VDC
- Arus kerja maksimum 10A dengan penundaan waktu, ambang batas Lux, dan sensitivitas yang dapat disesuaikan
- Sakelar sensor gerak gelombang mikro pemasangan tanam di langit-langit untuk beban lebih tinggi
- Input tegangan saluran 100-265 VAC, model 10A
- Deteksi gelombang mikro 5,8 GHz dengan penundaan waktu, ambang batas Lux, dan sensitivitas yang dapat disesuaikan
- Sakelar sensor gerak gelombang mikro terpasang rata (recessed) pada langit-langit
- Input tegangan saluran 100-265 VAC, model 5A
- Deteksi gelombang mikro 5,8 GHz dengan penundaan waktu, ambang batas Lux, dan sensitivitas yang dapat disesuaikan
- Dimmer sensor keberadaan PIR RZ037 pasang langit-langit untuk daya 220V
- Arus kerja maksimum 3A dengan beban terukur 660W
- Tombol LUX mengontrol ON/OFF sensor cahaya dan kecerahan redup yang diatur pengguna
- Dimmer sensor keberadaan PIR RZ037 pasang langit-langit untuk daya 110V
- Arus kerja maksimum 3A dengan beban terukur 330W
- Tombol LUX mengontrol ON/OFF sensor cahaya dan kecerahan redup yang diatur pengguna
- Sakelar sensor gerak gelombang mikro pasang langit-langit DC tegangan rendah
- Input 12 VDC / 24 VDC dengan rentang 10-30 VDC
- Arus kerja maksimum 10A dengan penundaan waktu, ambang batas Lux, dan sensitivitas yang dapat disesuaikan
- Sakelar sensor gerak gelombang mikro pasang langit-langit untuk beban lebih tinggi
- Input tegangan saluran 100-265 VAC, model 10A
- Deteksi gelombang mikro 5,8 GHz dengan penundaan waktu, ambang batas Lux, dan sensitivitas yang dapat disesuaikan
- Sakelar sensor gerak gelombang mikro pasang langit-langit
- Input tegangan saluran 100-265 VAC, model 5A
- Deteksi gelombang mikro 5,8 GHz dengan penundaan waktu, ambang batas Lux, dan sensitivitas yang dapat disesuaikan
- Sakelar sensor gerak PIR terpasang rata (recessed) pada langit-langit DC tegangan rendah
- Input 12 VDC / 24 VDC dengan rentang 10-30 VDC
- Arus kerja maks 10A dengan penundaan waktu, ambang batas Lux, dan sensitivitas yang dapat disesuaikan
- Sakelar sensor gerak PIR pemasangan plafon tanam beban lebih tinggi
- Input tegangan saluran 100-265 VAC, model 10A
- Deteksi 360 derajat dengan penundaan waktu, ambang batas Lux, dan sensitivitas yang dapat disesuaikan
- Sakelar sensor gerak PIR pemasangan plafon tanam
- Input tegangan saluran 100-265 VAC, model 5A
- Deteksi 360 derajat dengan penundaan waktu, ambang batas Lux, dan sensitivitas yang dapat disesuaikan
- Kit sakelar dan penerima nirkabel untuk kontrol pencahayaan ON/OFF dalam ruangan
- Penerima 100-230VAC, 50/60Hz dengan arus pengenal 5A
- Sakelar nirkabel berdaya baterai CR2032 dengan komunikasi 2,4GHz
- Okupansi (Auto-ON/Auto-OFF)
- 12–24V DC (10–30VDC), hingga 10A
- Cakupan 360°, diameter 8–12 m
- Penundaan waktu 15 dtk–30 mnt
- Sensor cahaya Mati/15/25/35 Lux
- Sensitivitas Tinggi/Rendah
- Mode okupansi Auto-ON/Auto-OFF
- 100–265V AC, 10A (memerlukan netral)
- Cakupan 360°; diameter deteksi 8–12 m
- Penundaan waktu 15 dtk–30 mnt; Lux NONAKTIF/15/25/35; Sensitivitas Tinggi/Rendah
- Mode okupansi Auto-ON/Auto-OFF
- 100–265V AC, 5A (memerlukan netral)
- Cakupan 360°; diameter deteksi 8–12 m
- Penundaan waktu 15 dtk–30 mnt; Lux NONAKTIF/15/25/35; Sensitivitas Tinggi/Rendah
- 100V-230VAC
- Jarak Transmisi: hingga 20 m
- Sensor gerak nirkabel
- Kontrol kabel (hardwired)
Pertanyaan yang Sering Diajukan
Does Luminance Mean Brightness of Colors
Luminance refers to a measurement that describes the perceived brightness of a color. It indicates how bright a color appears when reflected from a surface. Additionally, relative luminance is defined as the relative brightness of a specific point within a colorspace, with black normalized to 0% and white normalized to 100%.
What Is a Good Luminance
The recommended luminance ratio between the working area and the walls is less than 5:1. However, recent studies indicate that the luminance ratio between the working area and the normal field of vision (ambient area = wall/ceiling surfaces) should be 2:1, with an illuminance of 500 lux in the working area.
What Color Has the Highest Luminosity
Blue stars are typically the most luminous, while red stars are the least luminous. However, seasoned observers may come across red stars during nighttime that are brighter than white or blue stars.
What Is Normal Luminance
Earlier, normal luminance for normal activities typically ranged from 100 to 300 lux. However, nowadays, the light level commonly falls within the range of 500 to 1000 lux, depending on the specific activity. In cases that require precision and detailed work, the light level may even reach as high as 1500 to 2000 lux.
What Should the Maximum Luminance Be
SDR formats are capable of displaying a maximum luminance level of approximately 100 nits. However, in the case of HDR, this value significantly increases to a range of 1,000 to 10,000 nits. HDR technology allows for deeper black levels and more vibrant and saturated colors.
Does Luminance Change With Distance
With regards to point luminance, there was an observed variation of approximately 3% for every 1m increase in distance from the measured point. However, the influence of distance on surface luminance was comparatively less significant than that of point luminance. These findings from the study suggest that luminance values do indeed fluctuate depending on the distance at which they are measured.
