Focal Length - Bosch AVIOTEC IP starlight 8000 Operation And Commissioning Manual

AVIOTEC IP starlight 8000
Illumination is an important influencing factor for sensible optical systems. Natural light shows
the huge range of illumination values from direct sunlight (~100.000 lx) to full moon on a clear
night (~1.0 lx). A luxmeter can be used to measure the light levels.
The following table provides an overview of typical illumination values in different application
areas:
Application Area
Storage facility
Process plants
Sales room
Office space
In general a uniformly illuminated monitoring area is advantageous for the video-based fire
detection. Backlight should be avoided.
Dynamic range
The dynamic range is the ratio between the darkest spot compared to the lightest spot in the
application. Use a luxmeter to determine the brightness in your application. The dynamic
range in the camera image / the detection area must be equal or less than factor 5.
2.4.2

Focal length

The focal length of an optical system defines the distance between a light refracting lens and
the focal point. Field of view, maximum distance and field angle are dependant as shown in
the graphic below.
The maximum width of the field of view may be realized by the minimum focal length. This
adversely affects the maximum distance to a detectable fire (red).
Bosch Sicherheitssysteme GmbH Operation and Commissioning Manual
Illumination (in lx)
50
200
300
500
Introduction | en 9
2020.08 | 01 | F.01U.391.015