Wonderful shots, and equally wonderful story of how you got them. Here, in the northern hemisphier, we are waiting until March 11 to begin seeing Panstarrs, and hoping for clear skies. Any tips on exposure length and settings? Thanks, and good luck to all capturing images.
Most of my widefields are shot at 16mm f2.8 ISO 800 and 30 seconds or under. Occasionally I will bump up the ISO and shorten the exposure time and sometime's I'll go for a 400mm lens with a shorter exposure and higher ISO.
Comets are a bit more challenging especially when there is still sunlight in the sky, plus they move in a different motion to the stars, are faint and require a long exposure to capture, making motion blur more apparent. Trial and error I'm afraid.