SNR1s staat voor Signal-to-Noise Ratio 1 in Security applications
Sony introduceert een nieuw referentiegetal om de beeldkwaliteit bij weinig licht te beoordelen.
SNR1s is een kencijfer voorbehouden aan CMOS beeldchips gebruikt in CCTV camera's.
| IMX327LQR | IMX307LQR | ||
| Type | 1/2.8" | 1/2.8" | |
| Resolution | 1080p | 1080p | |
| PixelSize | 2x2 µm | 2x2 µm | |
| SNR1s | 0,18 | 0,24 | |
Hoe lager het SNR1s getal hoe beter de beeldkwaliteit bij weinig licht
| SNR1s [lx] Prescribed Conditions | |
|---|---|
| Application | Security Camera |
| Light Source | 3200 [K] |
| Target Object | 18% Grey |
| F number | 1.4 |
| Exposure time | 1/60 [s] |
| Linear Matrix | without |
| Signal | G [e-] (Sensor Raw Output) |
| Noise | √Shot Noise[e-] 2 + Dark Noise[e-] 2 |
| Signal : Noise | 1 : 1 |
Meetmethode SNR1s
Two 3200 [K] light sources illuminate an 18% gray chart from different directions, and dimming is performed to 100 [lx].
A camera is placed so that the distance from the gray chart to the imaging surface of the image sensor is 1 m,
the sensitivity [e-] and dark noise [e-] are measured, and SNR1s [lx] is calculated using the relational equation (1).
The luminance when equation (1) equals 1 is SNR1s [lx].
