Member Discussion

Planning Out IR For Monitoring Carparks?


I am considering a project where it is necessary to monitor fenced carparks at multiple locations in near total darkness because visible illumination is not desired for long periods when the premises are vacated.

After looking at your review of Axis VMD2.1, I feel we could have an option without the cost and disruption of installing traditional active quad IR beams to secure all boundaries. Advanced VMD in conjunction with Axton AT-7T Tactical IR Illuminators or similar seems like it could be a reliable combination and the monochromatic night-time images potentially much clearer.

My questions are:

1. Apart from the general increased cost both in equipment and installation, is there any disadvantage in using discrete IR illuminators when the cameras will adjust to the light level themselves?

2. Will I get a more even IR coverage when placing an array of IR floodlights (according to their specified beam angle) on the poles below the existing HP mercury/sodium vapour floodlights which are only used a few hours a week? An interesting consideration, from an environmental and economic perspective, is that each of the multiple existing gas discharge floodlights at each site consumes 250W or 400W. General lighting is not needed from dusk to dawn so sufficient IR illuminators of 7 - 30 Watts each should provide ample light for B & W surveillance after hours, reduce noise from AGC and lower the storage costs.

3. Finally, to capture good intruder images, would it be best to have the low light cameras mounted at an optimal height, but have the IR illuminators a little above on the same poles?

1. Integrated IR, from higher end offerings, including Axis', can automatically adjust IR power based on what is detected in the scene. Add on IRs cannot.

2. Are you considering turning off the visble lights? The problem with adding IR 'floodlights' is that any area close to the light source is likely to be overexposed. You could likely position the fixtures to minimize the problem but I am not sure why you want to add so broad of IR coverage when what is most important is directing the light at the areas directly in front of the cameras.

3. In terms of mounting IR illuminators higher or lower, we have not tested such positioning so I cannot offer an opinion.

Video analytics could be a useful tool to consider as well. I've seen it work in near darkness