how much battery does a device consume in sleep mode?

I use my device mostly as a camera and a flashlight when I work night shift. I only need the device 4 times during those 8 hours, 2 minutes each time the most (8 minutes total)

Would it make sense to turn the device off after using it or is the amount of battery I'm gonna save negligible?

Another question would be: Would it make sense to turn the device off when I leave the workplace? 16 hours of savings, or would this also be negligible?