I am working on a computer vision project that requires repeated measurements of the amount of light a specific building emits at night. I want to set up a webcam and a Rasperry Pi, and set it to take an image every 30 Minutes every night for a few months. From these pictures, I will extract the shape of the building, and calculate the difference in illumination between the building and the background. These measurements do not need to be super precise, and since I will use averages over time.
I have a Rasperry Pi 3, and am looking to purchase a fitting webcam. There are two common camera modules available, one with, one without IR filter. For night time photography, the IR-Version is usually recommended, but if I understand it correctly, those require IR illumination. Since we are talking about a building, illumination is off the table. Since the amount of light is my entire focus, I do not need the images be good, or even sharp. Just consistent.
Now I have the following questions:
Does a Non-IR-Filter-Camera make sense for this project, or should I rather stick with the normal camera module?
The maximum shutter speed for the raspberry pi camera module seems to be 6 seconds. I have not found any hardware documents for this, so can anyone confirm this?
Is this even a viable setup, or am I missing anything fundamental?
Thank you for your input!