Does anyone on here know why a camera's accuracy would drop when you reduce the delay time after the pulses?
You are essentially reducing exposure time, which will make the picture darker.

Some cameras can increase the voltage in the sensor to compensate (which will lead to higher noise), but adjusting the exposure time is the best way to change the sensitivity of the camera (typically, you'd determine the brightest pixel, and adjust the exposure time to keep it within a sensible range (e.g. 90% to 95%).