I remember reading that the controllers had to reprogram the flight control software before the encounter with Neptune to allow for longer time exposures. There just wasn't enough light for imaging at Neptune without long time exposures. The camera was designed for the light levels at Jupiter and Saturn. The light levels were much lower at Neptune and are much lower where Voyager is now. Damned shame, it'd be interesting to see if they could image something out there.

I remember reading in Scientific American magazine back in the 1980s about some of the things JPL had to do to image Uranus and Neptune. The JPL wizards did things like having the flight control computer automatically command small thruster pulses to correct for the torque effects of starting and stopping the data cassette recorder. Those folks are very good.