Wireless

I have to light a walkway along the side of an office building. The building is three stories high and the walkway is 190'. There are two cameras monitoring the walkway their height is ~16'(above the drop ceiling of the first floor). What is the best way to fully light the area? Wallpacks at the first floor drop ceiling height or from the roof? Less fixtures higher wattage on roof or more fixtures lower wattage lower down?

goose134

I think as long as the fixtures don't block the camera view or blind them with glare, either solution sounds good.

brian john

By no means am I a lighting expert, in fact I have tried to avoid any thing to do with lighting other than to provide power for lighting. But from photography, I have learned big lights result is less shadows, light situated further from the subject (within reason) gives more equal lighting and avoids shadows. Cross beam lighting and a whiter light.

Lastly do a web search and check with security firms asking what they prefer, this is a big market and I am sure there are some standards

simmo

I actually have some experience in this,
Firstly - as with all CCTV Camera installations, lighting is one of the hardest things to get right. As you are in the position to provide an illuminated area for people to move safely down a walkway, and it's monitored by the cameras, you will need to provide a balanced light suitable for both.
In saying that, it's easy to provide light to cater for one or the other, and this can be a problem, as CCTV images can become a white out with excessive light in the wrong places. Without knowing the type of lens the cameras are using ie: manual or auto iris, with or without back light compensation switching. For a distance of 190' the lens will need to be a 40mm if a 1/3" image sensor is used, or a 16mm lens if the camera has a 1/4" image sensor. you will have a hard task ahead of you to get this right.
Are the camera's setup with infrared illumination for night viewing?
If they are, then any forced lighting from the surrounding area will need to come from a location behind the camera's, otherwise the images from the camera's will be a wash out of white light. The other thing to remember is the lens in the camera should never recieve direct light into it's lens, so if you have to illuminate an area at each end of the walkway, the light should never be directly in the path of the camera lens at the other end.
A check of the Lux light intensity reading in the night without any forced lighting, will provide some valuable information for you (if the camera's are giving good images in daylight.) You should be looking for a reading of 1.0 minimum Lux in low light (Night time)
Additional lighting provided from forced lighting will bring the level down to around 0.05 which is ideal for the camera's to give brilliant images and should provide good illumination for people access.
Incidently, Black and White cameras will give a far greater quality image in low light areas than Colour camera's will provide, this is due to the image sensor used in Black and White camera's.
Try using a Flood type light 500 watts each, mounted behind the cameras, and at least 10' above them. This should be o.k over the distance you need to cover.
Good luck with it.