Reflected light is that which is reflected off objects and people in the field
of view.
Light strikes an object and bounces off it. The light then passes through
the lens, strikes the image sensor, and creates an image. Different materials
reflect light at different rates. The table below lists several common
areas or objects and their reflectance values, or the percentage of light reflected
off them.
| Scene |
Reflectance Factor |
| Empty asphalt parking lot |
5% |
| Parkland, trees, grass |
20% |
| Red brick building |
35% |
| Unpainted concrete building |
40% |
| Parking lot with cars |
40% |
| Aluminum building |
65% |
| Glass windows and walls |
75% |
| Snow |
85% |
The amount of illumination available, in conjunction with the camera's sensitivity,
is crucial information when selecting a camera for your application. Illumination
and sensitivity have an inverse relationship: more light requires less sensitivity,
and with less light, higher sensitivity is required.
