I was testing 4 things with this shot.1) Battery Life
2) Artifacts & Pixel Errors3) Noise Levels and Noise Reduction
4) The BULB feature
I have to say that the camera outperformed my wildest expectation on all four point... but it was notable that the NR feature - in camera - was VERY slow. It took 10 minutes after I ended the exposure for the camera to process through the noise reduction. But to the camera's credit, this is one super-clean final image. Very little - almost no noise or grain from the long exposure. It's as good as any 35mm shot I've ever done of star spin - and I was honestly just playing around - not sure if I'd get anything at all.
Nikon F5 - 35mm film
24mm Nikon Lens (AF-D f/2.8) 20 minute exposure on Ektachrome T320 reversal stock Aperture was set at f/8 Focus set to infinity.