Camera Responsivity Question

I like to use a mono camera with 4.8V/lux-sec responsivity to take a picture. This will be a short duration, low exposure picture. I need to illuminate the subject, I am trying to find out what type of irradiance I should target at the sensor to get a decent picture.

Are there any guidelines for this?

I assume you mean ....... I am trying to find out what type of irradiance I should target at the subject to get a decent picture.

Have you tried Infrared, it would be the norm for low ligh situations ?. OF course that would depend of what your subject is ?

cheers
Dave