I have a scenario that requires manually setting the aperture and focus on a lens attached to a machine vision camera on an outdoor scene (mirrorless camera with global shutter). I need to manually set the aperture and focus to best handle the outdoor scene during very low light conditions (i.e. just after sunset). However, because of security concerns I do not have access to the camera during these low light time periods, making it impossible to set the aperture and focus during the lowest lit conditions.
One theory I had was to use the relationship between LUX and EV to simulate the low light conditions during the day. Basically I would purposefully be under exposing daytime images at a level that simulates my twilight lighting conditions and then use those settings to set the aperture and focus during the time I have access to the camera. I am able to get LUX measurements of the scene for my night time lighting conditions.
Would this work? If so, how?
Any other suggestions for how to overcome this issue?