What should you do for dark outdoor scenes? Thermal cameras are getting a lot less expensive. Conventional cameras are getting better in low light. We decided to test these two categories - thermal and day/night - head to head to better understand what's better to use.
We tested in a large outdoor level field, overviewed below:
Three cameras were used:
- A DRS WatchMaster IP Elite, 320x240 imager, with a 40-degree field of view. Other cameras were matched to this field of view.
- Axis Q1602 with Computar F1.0 lens.
- Bosch NBN-932V with Fujinon F1.2 lens.
The DRS was selected because it is the least expensive thermal IP camera on the market while the Axis and Bosch were chosen do to their strong performances in previous low light shootouts (see the Q1602 test and the MP low light shootout).
The following scenarios were tested:
- Daytime, between ~4500-5000 lx (a partly cloudy day).
- ~0.1 lux with both visible cameras defaulted, 1/30s shutter speed, day/night set to auto.
- ~0.1 lux with the Q1602 set to 1/30s shutter speed, in black and white.
- ~0.1 lux with the Q1602 set to 1/2s shutter speed, in color.
- All tests were performed at ranges between 150-550', the specified limit of human detection range of the DRS camera.
With this approach, we could determine not only what was 'best' in low light but what tradeoffs existed during the rest of the day.
This is the first in a series of low light shootouts. Stay tuned for Thermal vs IR Illuminators and a Thermal camera shootout (featuring Axis, Bosch, DRS, FLIR, Pelco and Sightlogix).