wimvb

Yes, it's called Stargazers Lounge. Good polar alignment is important, but if it's longer exposures you want, guiding is the way to go. With that comes the need for a computer. And with that comes the possibility to use software for polar alignment. For example phd, sharpcap, or ekos/kstars.

Yes, I found the same. What Meade calls polar alignment, is go to alignment for skywatcher. You can do as you write, but you need to know polar error direction. Is your setup permanent or mobile/grab & go? If mobile, you should consider just using the polar scope. Other methods take time. Unless you throw money at the problem, of course (qhy polemaster).

Yes, it's probably named "polar alignment" or "all star polar alignment". Any polar alignment procedure will require you to center a star using the azimuth and altitude knobs on your mount, not the keys on your hand controller.

Throw away data or not, I think you have a very nice image there with lovely detail. I'm not sure Sii adds anything to the image. Have you tried processing the data as a bi-colour?

To get colour, you'll obviously need colour filters. If you don't have too much light pollution, go for 4 filters: L, R, G, B. If you do have light pollution, just R, G, B may give you better results than L. Or you can use a lp filter instead of L. Be aware that to capture dark dust and ifn, you will need long integration times.

I believe so.

Very nice image! Which eq mount do you have? If it is a goto mount, it's very much possible that it has a polar alignment function. This will be much faster than drift alignment.

32 bit floating point, afaIk.

I don't think there's any area with background. It's all nebulosity. If you use DBE, you try to put just a few markers on any poisition where you want to have the same value after correction. Then you use "normalize" in the correction tab of DBE. This will keep the "average" colour and won't do a neutralisation. Many people don't use this feature and let DBE neutralise the background. This is improper use, imo. It makes more sense to me to let the correct process (background neutralization) do that. Arcsinh stretch keeps the colours intact, even at high values. Histogram transform will brighten all high values to white, while masked stretch works the same, but protects highlights in each iteration. The masking suppresses or delays this whitening effect, but only arcsinh stretch actually keeps colours as they were in the linear image.

Until then, it's a cyclops.

Here are my attempts at NB processing. Used PixInsight Basic process: linear fit (histogram alignment) with O3 as reference channel combination cropped edges DBE to remove gradients background neutralization (using the dark nebula in the center as a reference) reduced the green a bit (scnr at 50%) removal of purple halos (invert, scnr, invert) arcsinh stretch contrast enhancement with curves stretch colour saturation star reduction removed more of the green with scnr at 50 % resample For the second image, I did the last scnr at 100%

You need to connect to a computer. Most camera manufacturers offer their own software. Other options are ASCOM based (windows) or INDI based (linux) solutions. Your workflow will depend on the software used.

As I reported yesterday, first light of the obsy was a mixed success. DEC guiding was all over the place, but RA was pretty good. Rather than spending the entire cloud free spell trouble shooting, I decided to go for short exposure AP. So, here's my first ever Orion nebula/Trapezium. (I haven't imaged this nebula before, because it was always obscured by trees or to low over a neighbour's house.) Ok, not my usual standard. But this is only a very Quick & Dirty processing of 4 minutes (!) worth of data before clouds spoiled the fun. R: 25 x 3 seconds (75 s) G: 25 x 3 seconds (75 s) B: 30 x 3 seconds (90 s) I haven't taken any calibration files yet, so this is just stacked, and stretched of the raw image files.

Two pairs of socks and a styrofoam block to rest your feet on. If you can keep your feet warm, it's a lot easier being out in the cold. "Up here" it may get a lot colder, but fortunately humidity is also a lot lower, so it doesn't feel that cold.

Yesterday I collected abt 880 frames. Thank heavens my camera is only 2.3 MP, file size 4.6 MB. But that's still 4 GB for one night. Unfortunately I had to throw the majority out due to clouds and the target disappearing behind the obsy wall. I must install my cloud detector.

... and setting up in Ubuntu is easy. Just connect to the ppa and sudo apt install.

@fozzybear: I believe the correct fl is 180 mm. At least that's what I found when googling the subject. @Gina: I use both the internal guider and phd2 for guiding with a ASI120MM-S and oag. Either works, but I find phd2 more transparent. It's easier to see what's going on, and there are more guide algorithms to choose from. I particularly like ppec (predictive pec). It also has more analysis functionality, should guiding go wrong. The built in guider is based on lin_guider, very basic and more push here dummy than phd.

The first imaging night from the obsy has come to its end. Just before midnight clouds rolled in again. I started imaging ngc 925, a small but very nice galaxy in Triangulum. Focusing the guide camera wasn't any trouble. I focused the imaging camera with a Bahtinov mask on Capella, then moved the scope until I could see that star in the guide scope fov. Moved the guide head until the Bahtinov pattern indicated focus. Easy. I had some problems with devices not connecting, and I had to add a usb hub to get stable connections. I lost connection between the obsy network and my computer indoors a few times. Solved that by moving downstairs and connecting with an ethernet cable. Finally I found out that the mount had been in summer storage too long. Guiding showed severe backlash/stiction in DEC, which I will deal with tomorrow. Guiding RMS was 0.55" in RA, and a whopping 1.5" in DEC with a devastating saw tooth pattern. I will also need to check if the scope is balanced properly. I turned off guiding and went for bright targets with short exposures instead: Taygeta in the Pleiades and M43. This worked good enough untill the clouds put a stop to the fun. Tomorrow I'll take calibration frames (saw some dust bunnies on the light frames), and start tinkering with DEC. All in all I'm pleased to be back in business again. Next session I will test guiding and automated flips.

Mine is wrapped in wire. Although not silver. Titanium is more likely.

Like the Death Star, my observatory is operational but not yet finished. Here it's waiting for some action tonight. To the East, the other roof half is an obstruction when closed. I will see how it goes, otherwise I can always open that half too. But there will always be the fixed beam. A good thing is that the roof can be closed with the telescope in any position. In case of an emergency, I don't have to park first. With the opened roof in the position it is, I have a free view of the forrest on the other side of the field. If it turns out that the scope is positioned too low, I can always extend the pier adapter a few inches. Better a pier that is too low than one that is too high. It's future proof. "It's not a bug, it's a feature."

My dew heater is just a resistor ladder with some 10 or so resistors in parallell. Soldered to two, stripped, multi strand copper wires and sandwiched between layers of duct tape. Short pieces of sticky velcro at each end to hold it in place. I've used this to warm a 135 mm lens and later around the stalk of the secondary of my 150pds. I have used it with a pwm LED controller, but also on full whack with just a 12 V battery. "K-I-S-S"

I think so. 👍

Ha ha, @niallk. They probably thought you were peeping. 😋 Nice though that you got a clear night.

Very nice. You still have very dark corners. Did the flats do their job properly?

Very nice first results. M31 and M42 are bright, so 1 sub already shows a lot. But the weaker targets demand more signal (= stacking). Have you figured out why dss didn't give you better results? How many subs were actually used in the dss stacked image?