Not much detail for periodic comet 24P/Schaumasse, which was low to the horizon over a stronger LP dome when I started taking the sub-images for this shot. I thought it might have a discernible tail that my camera might pick up since Cartes du Ceil showed it with one. LoL! Unfortunately, no software (or humans) can predict exactly what comets will do, which is why they make such good astrophotography targets. 😉
Here is a quickie of 62P/Tsuchinshan. Only 8 sub-images, but it went deep enough to pick up a few faint fuzzies. The comet was predicted to be dim, so I was not expecting much from it. My main target this night was another comet just a few degrees away, which is why I did not spend much time on this guy. But, it looks promising and I might try for it again soon.
There is something weird about this stack, though. Some sort of artifact, maybe? It looks like two tails, but I can’t be sure. Its more apparent in a negative view of the star-streaks image:
I also have a full-field, star-freeze view at 100% resolution. It is more “pristine” than the other images with only minimal processing :
On this night, I drove out of the city to a semi-dark spot about 30 minutes away. It was forecast to be very transparent, according to ClearkDarkSky.com. Moonset was near 1:00 AM on Sunday morning, Oct 29, 2017, so I setup and took advantage of the dark time that was left and managed to shoot 3 comets before sunrise.
The first one was Comet Asassn. I processed it and created an initial star-streaks version, since it is the easiest to do. I still had a set of ISO 3200 sub-images to add in, but it looked fine to me with just the ISO 1600 data, so I left it as is. Plus, the two data sets did not mesh well with so many stars and the differing exposure times.
For the star-freeze version, I did add in the ISO 3200 data, which was 36×180 sec. Check it out:
Here is the full-field version of the above with a slightly different color balance and saturation level:
This is one of those early morning comets that are low to the horizon at dawn and very dim. Consequently, 2 minute sub-images at ISO 200 barely picked it up from the Bortle Red Zone glow I was shooting in.
I could easily see two 11th magnitude galaxies nearby in the sub-images, but this guy was barely visible. I think it is supposed to get brighter before too long. I will try again for it if and when it does.
The moon was low and setting in the west when I took this shot. Earth-shine was very pretty and I tried to capture how it looked, but the bright part always gets over-exposed. But, you get the idea. 🙂
Here is a one exposure image taken in the middle of a Bortle Red Zone with 2 light pollution filters in place to help with all the LP. I managed to get quite a bit of nebulosity with 5 minute sub-images at F/2.8 and ISO 200 on my older, modified Canon XS camera.
What helped was the sky conditions, which were very transparent and clear. I am glad I did not waste one of the few great nights of the year.
The above image is just a tease, btw. I have a number of these subs just waiting to get calibrated, stacked and processed. I will probably just tack the finished product onto this thread when I am done.
There you go. Tacked on as promised. lol I accumulated almost 2 hours worth of data and considering the location, it did not come out too bad.
I tried for Comet Asassn and even with 60 subs, I did not get much. The Canon 200mm F/2.8 lens was just too small of an image scale to do it justice. Bortle Red Zone conditions did not help. Plus, the parking lot lights from the nearby theater were still on for most of the imaging session. When they go off at 2:30 am, I can see about a mag to a mag and a half dimmer stars in the sky. I can do 5 minutes exposure instead of just 3 with them off and it makes a difference in the final outcome.