Sunday, February 19, 2017

#76 - Sunday, February 19, 2017 - The Big Leagues

Another clear night!  And it was a little darker than Friday night.  It looked like some clouds were going to roll in around 10 PM, but that didn’t happen, thankfully.  Although I did get some ground fog around midnight – however, the telescope didn’t seem to care and saw right through it.  I did have a battle royale with dew though, which killed my external battery before I plugged the dew heater in instead. 

I started out with the Rosette Nebula, a new target for me.  It’s too big to do with my 11-inch, although I might try a mosaic sometime if I can get that process down.  I could just barely make out some differences in contrast in the subframes, but HOLY COW did this come out awesome!  It came out all right from DSS, but a little Photoshop really made it pop.  Since my camera isn’t very sensitive to red, I have to massage the colors a bit to make it more realistic.  This one is probably my new favorite.
Rosette Nebula, Nikon D5300, Vixen NA140ssf, Astronomik CLS filter
Guiding: QHY5 on Celestron 102mm
23x300s, ISO-1600
[Note: This is now an award-winning image!  I won second place in the 2017 OPT/Astronomical League astrophotography contest in the Deep Sky category!]

The detail is amazing, and I even picked up some of the blue from the cluster in the center.  Oh, also, an AstroBin user commented on one of my images and mentioned a piece of freeware called Noiseware (well, there’s a paid version too, but they have a free version) that really does a wonder with noise.  I tried Photoshop’s noise filter, and it doesn’t even come close.  Unfortunately, it only saves out small jpeg files (a couple of MB), so not good enough to print.  I’ll have to see if I can either get Photoshop’s to work better, or see if the paid version does TIFFs.  
I think I will use this one for my upcoming astrophotography talk to my club, since the subs have a lot of skyglow and you can barely make out the nebula:

After 2 hours on Rosette, I switched over to the Pleiades before they set, and I did have to re-sync the mount, even though they are nearby.  Luckily, its guess was okay for the sync star, and I didn’t have to go that far.  I was planning two hours on it too, but it dropped below 20° altitude before then, and the pictures started coming out crappy.
M45 Pleiades Cluster, Nikon D5300, Vixen NA140ssf, Astronomik CLS filter
Guiding: QHY5 on Celestron 102mm
15x300s, ISO-1600

Since this one is all blue, color balance was simple, since the filter lets through blue light the most already.  I think it captures the nebulosity pretty well, although I’ve seen better.  I might re-process to make the blue a little bluer and a little less green – I’ll have to go look at some pictures to get a good idea of what shade the blue should be.
It was just about midnight, but I wanted to get one more target in, since Monday was a holiday anyway, so I flipped around to the north to do the Leo Triplet.  I got it synced to nearby Denebola, but then my guidescope started acting up.  The new darks library I took (I didn’t realize yet that I could import it from my CGE profile in PHD) for some reason added a high background, and then sometimes the whole field was just gray with no stars.  I checked focus, shined light in it to make sure it was still reading, and finally got it working again by unplugging and replugging it, and restarting my computer.  Then I also imported the old darks library.  That seemed to get it mostly going.  That and taking test images took 45 minutes.  So I did an hour and a half on the Leo Triplet, and called it a night.  Again, I left at 2:30.  The fog was quite thick on the drive home, but luckily it still didn’t take much longer.  Galaxies are very hard to white balance with a light pollution filter, and the CLS is no exception.  My attempts in Photoshop just introduced a bunch of noise. So I gave up and kept them more or less blue.  Also, they must have turned off the lights at the nearby dairy farm because I was able to do 5-minute exposures at ISO-3200 without too much background.
Leo Triplet (M65, M66, NGC 3628), Nikon D5300, Vixen NA140ssf, Astronomik CLS filter
Guiding: QHY5 on Celestron 102mm
16x300s, ISO-3200

So yeah, a great night!  I am very pleased with the Rosette Nebula!  The memorial scope is fun to image through because of its faster focal ratio and large FOV, and also how I can get everything set up in like in 20 minutes, but the large FOV also really limits what is worthwhile to image because a lot of interesting things would just have too few pixels on target, such as M51 and the dearth of other galaxies up during the wintertime.  And for those dimmer galaxies, only 5.5 inches of aperture doesn’t do much for you.  But the flat field and pinpoint stars sure are nice.  I need to look into off-axis guiding or something for my 11-inch so that I don’t get flexure issues from the mirror moving around.   Once I get that mount fixed.  I might just send it off to Clay Sherrod to deal with.

Friday, February 17, 2017

#75 - Friday, February 17, 2017

I did go ahead and get that CLS filter, from Astronomik.  Color balancing is easy on nebulae, but hard still on galaxies.  I will have to work on that one.
The evening started off rough – Jim did some adjustment on the polar alignment, which appears to have made it worse.  I couldn’t even do 45 seconds unguided without streaking.  I tried again with my QHY5 guide camera, but I didn’t quite have enough backfocus on the guide scope.  So I took a bunch of short exposures on the Flame and Horsehead Nebulae, but then Jim on Facebook suggested I use a star diagonal for the extra length.  It worked!  Soon I was up and guiding.  This was after some guests I brought had left – so I was running in and out of the dome before, trying to show them stuff.  Luckily, the three other club members were there, who were happy to share their views in the big Dob owned by the club.  My guests, a father-son duo, I met by club member Phil, who arranged an interview from the son to me about differences between refractors and reflectors for his middle school science fair project. 

Once I got guiding going, things went great from there!  I imaged the Flame and Horsehead Nebulae, and then M81 and M82.  They came out great!

Flame & Horsehead Nebulae, Nikon D5300, Vixen NA140ssf, Astronomik CLS filter
Guiding: QHY5, Celestron 102mm
25x180s, ISO-1600

M81 & M82, Nikon D5300, Vixen NA140ssf, Astronomik CLS filter
Guiding; QHY5, Celestron 102mm
21x180s, ISO-3200

I still can’t quite get the memorial scope to do a proper alignment, so I just sync on a nearby star and then guide.  That seems to work great.  I haven’t tested how long it will guide for yet.  At least 5 minutes with still very nice stars.  I was out until 2:30 AM!  So glad to finally have some clear weather.

Thursday, February 2, 2017

#74 - Thursday, February 2, 2017 - Refractor imaging

[I will make a separate post detailing what exactly happened to my CGE mount.  I didn't include all of those details in my original log entries.]

It was clear last night, but I didn’t believe the forecasts, so I made other plans!  Luckily, the sky cleared up for a little while tonight too.  The drive over to the observatory was cloudy, and while I was getting set up it was cloudy, but then things finally cleared up after I took some “consolation prize” video of the moon and Venus. 

I still can’t get the memorial scope to align properly.  Well, firstly, I wound up having to use the Telrad that Jim recently attached because the finderscope is way not in alignment and I can’t figure out how to align it.  I followed the instructions more carefully this time.  My first attempt, I used Betelgeuse as the sync star, and then something else I can’t remember as another alignment star, and then something in the west I can’t remember, but when I slewed to the moon, it was way off.  Venus too.  Then I had to slew to another star for another alignment, but it was super off.  So I shutdown the mount and restarted, and its initial guesses were good for Betelgeuse and Pollux, but it wouldn’t let me add it.  I checked that I was doing things in the right order.  I tried another star farther away, but still no luck.  So I slewed over to the moon manually and took some video, and then some for Venus.  They were both pretty rock solid in not moving, so I figured it must be well-enough polar aligned that alignment doesn’t particularly matter.  I didn’t have goto, but the moon was too bright for the dim stuff anyway.  After the videos, I manually slewed over to M42 (of course), recognized its dim greenish form and two stars of the trapezium in the viewfinder, and started imaging.  The moon was too bright to do very long exposures, especially at that scope’s focal length – f/5.7 – so I did 60s at ISO-1600.  It’s still too bright, but we’ll see how it turns out.  I took 20, and then I decided to try my luck with the Flame Nebula and Horsehead Nebula, since they’re super easy to find right there next to Altinak.  I could just make out the Flame Nebula in the frames where the background wasn’t blindingly bright, but Altinak is so bright too.  We’ll see what stacking and processing can do. 
[There were some thin high clouds that made some interesting halos around the brighter stars, but overall not bad!]
M42 Orion Nebula, Nikon D5300, Vixen NA140ssf
21x60s, ISO-1600

After getting 40x90s images on Flame/Horsehead, the clouds began to reappear, so I packed up around 10:30 PM.  Not a bad night!  I meant to also test how long the tracking is good for on the memorial scope so I’ll know if I need to even guide or not, but I forgot at the end, and it was getting a little cloudy anyway to be able to make out exactly how round the stars would be.  But Jim said he plugged the Malincam into it back in November and had nice round stars at 3 minute’s exposure.  So I’m curious to see whether I’ll even need to guide with it.
Flame & Hosehead Nebulae, Nikon D5300, Vixen NA140ssf
18x90s, ISO-1600

I’ll see if I have time to process the images in the morning; I don’t expect much, but why not.  Can’t wait for a darker night!  And probably a CLS filter.