Commission illumination as part of the camera system

Bottom line: a lux value at one convenient point cannot accept a camera scene. Useful illumination must reach the subject with the right distribution and spectrum while avoiding glare, deep shadow, overexposure, and motion blur.

Source fact: quantity, quality, and distribution all affect video

Axis’s Lighting for network video explains that camera performance depends on the quantity, quality, and distribution of light. It says an illuminator beam should match the camera field of view, discusses the rapid reduction in illumination with distance, and distinguishes visible and infrared illumination. It also notes that surfaces reflect light differently and that accurate color requires suitable visible light.

The camera and lighting design therefore share one acceptance task. A bright foreground can force exposure down while the required face or vehicle remains dark farther away.

Source boundary and applicability

The paper provides Axis guidance, not a universal lux threshold or photometric design for a site. Camera sensitivity claims, lux measurements, spectral response, lens, exposure, weather, dirt, subject reflectivity, ambient competition, and mounting geometry affect results. Lighting work must also follow applicable electrical, glare, accessibility, environmental, and neighborhood requirements.

Applicability questions

• What subject and detail must be captured at each position in the task zone?
• Is usable color required, or is monochrome infrared acceptable?
• Do the camera field of view and illuminator beam remain aligned at all required distances?
• Which signs, plates, clothing, walls, moisture, snow, or vegetation can create reflection or shadow?
• What happens when adjacent lights fail, dim, cycle, or are controlled by another system?

DSE recommendation: accept light and recorded image together

The following steps are DSE recommendations based on the cited source.

Create a plan showing camera views, target planes, illuminator locations, beam coverage, ambient sources, and required image task. Take documented measurements at representative target planes using appropriate instruments, but make the retrieved recorded video the final operational test. Walk realistic subjects through near, middle, far, edge, shadow, and reflective areas under the darkest expected condition.

Inspect exposure time and motion detail, not only brightness. Adjust beam, placement, output, camera exposure, or supplemental light through coordinated change control. Confirm the design after a light failure and after the site switches between operating modes.

Record who owns lamp replacement, cleaning, aiming, seasonal inspection, and notification when an external lighting system changes state.

Verification and evidence

Retain the lighting and camera plan, equipment models, measurement method and readings, weather and ambient conditions, camera settings, native clips from every test position, motion-detail assessment, failure-mode result, and acceptance sign-off. Re-test after landscaping, signage, surface, lamp, camera, lens, or exposure changes.

Official references

• Lighting for network video – Axis Communications