My 5″ astrograph is fitted with a multi-pass, narrowband filter. This filter is ideal for imaging emission nebulae and stellar nurseries. It isn’t the right kind of filter for galaxies, clusters or comets. Nonetheless, I tried to photograph this comet last night. It would have been much better to replace the narrowband filter with a light pollution suppression (LPS) filter but doing that would have been a pain in the butt. I really need to get a filter changer to make this chore simpler. I’m going to look for one online this evening.
The image below, sorry as it may be, is the composite of 11, 6-minute sub-images. The head of the comet is the fuzzy ball to the right of center. This comet has a visible tail, but it is not captured in this picture.
C/2017 K2 Pan-STARRS is located in the constellation Ophiuchus right now, and it is probably visible in medium-power binoculars and small telescopes. The ephemeris for the comet is available online.