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Here's your image, processed in PixInsight. Gradient removal; as @vlaiv noted, there is vignetting in your image. extracted luminance rgb: colour calibration chroma noise reduction arcsinh stretch histogram adjustments desaturated the background l: noise reduction histogram stretch in multiple steps hdr compression curves transformation lrgb combination I kept the background intentionally a bit dark in order to suppress the walking noise. With a dslr, dithering is your best friend. Btw, since your gradient is uneven across the field, you may want to move the secondary mirror so that it is centred in the focus tube. If you like tinkering, that is. This is the background of your image, as extracted by PixInsight, stretched

Do you have a coma corrector with that scope? With a DSLR you really need one. If you already use it, you might want to check its distance from the chip, there is severe coma in the corners of your image.

I just downloaded your image and opened it in PixInsight. What scope did you use? How large is your scope aperture compared to the screen? Make sure that the light source covers the whole aperture with room to spare. Also avoid too short exposure times. You may need to fold that cloth several times to get an exposure time that is long enough. With a mechanical shutter, you want an exposure time that keeps the whole shutter open long enough that the screen refreshes a few times. Alternatives to a computer screen is an LED panel. Your image has running noise (or walking noise) in the background. While this can be held back during processing, it's better to avoid it all together by dithering during capture. http://wimvberlo.blogspot.com/2016/07/dithering-in-hardware_7.html http://wimvberlo.blogspot.com/2016/07/the-effect-of-dithering_21.html

In case you're interested in INDI/Kstars, the StellarMate is probably more plug & play than a clean raspberry pi. AsiAir is limited to zwo cameras + dslr only. An alternative is a minipc or compustick near the mount connected to the warm room laptop with an ethernet cable. That way you can continue using ASCOM based software.

I posted my ngc 2683 on the Swedish astroforum, and got some interesting feedback regarding the objects near PGC3452022 in the upper right corner of my image. It turns out that this is in fact a galaxy cluster that extends beyond the fuzzy area indicated by the ellipse my image. The cluster name is ZwCl 0848.5+3341 and it has a redshift of 0.38 (NED says 0.37), which puts it at a distance of a whopping 5600 Mly, if I do the calculations right. The galaxies are also giants; the one indicated by the number "8" has a magnitude of 20.8 and a size of 450 000 ly. In comparison, our own Milky Way is "only" 100 000 ly in diameter, and ngc 2683 a mere 78 000 ly. Cool stuff!! I haven't checked these facts (magnitude and size), so I rely on the feedback I got. According to SIMBAD, there are 98 galaxies in this cluster. Btw, the cluster may extend to the small galaxies indicated by 1 and 5, between the main cluster and ngc 2683. But when I enter their data in Vizier/NED, I get much smaller redshifts. These galaxies should be much nearer.

For darks to work, their temperature needs to match the temperature of the light frames. Since you can't control that temperature, darks may not work. Some astrophotographers get good results using darks. Others, including me when I used a dslr, don't see any benefit with darks, and don't use them. There's only one way to find out: experiment. Integrate a stack with, and the same stack without darks. Then compare the result. If the image is the same or better without darks, you don't need them and you can leave them out of your workflow. Since flat darks have a shorter exposure time than ordinary darks, usually you don't need them. You can then just replace them with bias. The frame types you need are then: lights, bias and flats. Correct I always use manual settings for AP. That way I know the settings will be the same. In any case, make sure that iso is the same.

It seems to me that you got guiding under control. Nice round and tight stars.

Couldn't disagree more. 😉 The image looks great.

I must be older. To me, these are the only true floppy disks https://www.renderhub.com/firdz3d/floppy-disk-5-25 They also came as 8 inch disks. I've also stored computer programs on audio tepes. Anyway, back from memory lane, I keep the original raw files and discard all calibrated/registered files. I don't store intermediate images. PI will store a complete history in a project file.

Both cameras use the same sensor, as far as I know, sensitivity should be the same. But a usb 3 camera should be faster in sending images, hence a higher frame rate. You should also check which software supports either camera.

With a dslr: Bias frames with the lens covered (a plastic lens cap is not enough), same iso as lights. Shortest exposure time possible. The more the merrier, but at least 50. Darks with the lens covered (a plastic lens cap is not enough), same iso and exposure time as lights, and as close to the same temperature as possible. As many as possible, at least 20. Flats, at the same aperture as the lights, if you use a lens. Preferably also the same iso, but not necessarily. Note the iso and exposure time. Flat darks, at the same settings as flat frames (iso, time) with the optics covered. Bias and dark frames correct electronics in the camera, so they need the same electronics settings: exposure time, iso and temperature, as the light frames. Flats correct optical issues (shadows from edges and dust), so they need to be taken at the same optical settings as the light frames, same aperture, camera orientation, etc. Flat darks correct the electronical issues of flat frames, so need the same camera settings as flats, iso, temperature, exposure time. If you use darks and flat darks at the very same settings as lights and flats, you don't need bias frames. Otoh, darks don't always work with non-cooled dslrs, and you replace them with bias frames. You can also replace flat darks with bias frames.

Great image, Gina. It seems your building projects are a success. I can never get this to work. I always have to go over to the rig and put a B-mask on my scope to get focus. What settings do you use in the focus module?

Colourful. There's a lot going on in this image, but the bubble is the centerpiece. I think that with this much glowing gas, nobody even thought of naming that dark streak. Maybe it's up to you?

It's always interesting to find out how deep we can actually go with modest equipment (in this case a SW MN190 telescope on a AZ-EQ6 mount, and a ZWO ASI174MM-Cool camera). Yesterday I posted my image of galaxy ngc 2683 in Lynx. Since it's clouded over now, I decided to investigate some of the background galaxies in this image. I started with the image solver in PixInsight to list the most common (PGC) galaxies But this left some unanswered questions. The obvious one that image solver missed is the small galaxy right next and below of ngc2683. Then there are several other faint fuzzies that the image solver missed. I did an on line search and found an image on a Germain website that gave more information. http://www.astro-photos.net/CCD/NGC2683_cctv.html Among others, it showed a very weak dwarf galaxy that should be in my fov. A further reference to this dwarf galaxy is in a paper on arxiv.org https://arxiv.org/abs/1511.00955v1 To see if I captured this object, I superstretched the luminance data. I moved in the black point and white point so far that the main galaxy is completely burnt out, and anything faint in the background will show up. Next I inverted the image, so that it will be easier to see dim objects. I then annotated some of the objects. One of two dwarf galaxies from the German site and the cited paper is indeed visible in the lower left part of my image. What is also interesting is the cluster of objects in the upper right corner around PGC3452022. This will need some further investigation. (click on the image to enlarge it) Edit (27 jan): New information further down this thread.

Thanks, Dave. As it turns out, I have now imaged this galaxy on three different occasions; once with my 150PDS, once with the MN190 from a roll off shed, and now from my obsy. The latest version shows that gathering a lot of data is the way to go. It allows for better processing. And my new obsy makes this possible. I would never have been able to collect almost 12 hours of data on just two nights without it. Version 1 https://www.astrobin.com/385700/C/?nc=user Version 2 https://www.astrobin.com/391240/B/?nc=user Version 3 https://www.astrobin.com/jd2hjn/?nc=user

The recovery goes well, thank you. There are now at least three of these that I know of 😁; two single pier observatories by Göran, and a dual pier version by me. I think that Göran could have made a traditional ror if he'd wanted. In his original design, he let the roof slide down to the ground on two removable beams. He later added the raised supports. The sloping roof design has several advantages, one of which is that it's simple while easy to clear from snow. Another is that it allows for a lower south facing wall. The disadvantage is that if it runs as smooth as it should, the roof will open by itself, and you have to lift it to close. So you do need a winch. Since I'm on a south slope, a traditional horizontal running roof to the north would be very impractical unless I'd raise the whole obsy. There's simply not enough clearance to the north. East/West sliding roofs would result in a very long and heavy construction, at least 8 m overall. Plus obstructions to both East and West. As it is, the observatory fits very nicely with the surrounding landscape.

I had something similar in mind. Or a bit of aluminium tape around the bolt near the head. I probably drilled a 13 mm hole to accept a 12 mm bolt for easy assembly. But at the time I didn't consider that this would affect polar alignment. Ah well, I'm an electrical egineer not a mechanical, by trade. There's always the possibility of a V 1.2.

Proper first light, 2 nights spent with ngc 2683. Using the obsy, some things become apparent. Guiding has to be improved. The guide graph shows what is either backlash (DEC) or stiction. I tried to wiggle the saddle, but it seems stable enough, so I will poke around with allen keys to see if the DEC axis is actually a bit too tight. The roofs are not sliding smoothly enough. Especially the roof half over my scope is difficult to open and close. It will have to do this season, but during summer recess I will install a proper V-rail with metal wheels. I have ordered an anemometer to complement my weather station (which is not installed yet). I will probably redo the housing for the weather station also. After that, integration with Ekos, so that at least I will get warnings when clouds roll in or the wind gets too strong. The East pier has to be made higher. I will adjust the adapter height about 2 - 4 inches. Apparently the EQ6 is a bit smaller than the AZ-EQ6. The hole that I made in the pier adapter for the central bolt underneath the mount, is slightly too large. This makes it more difficult to do AZ adjustments during polar alignment. I'll fix that by inserting a piece of metal or plastic around the central bolt. As it is, the bolt & mount can move sideways when you tighten it after polar alignment. I hadn't really thought of this when I designed the pier adapter.

Ngc 2683 is a type SAb galaxy in the constellation Lynx (RA: 8h 52m, DEC: 33 deg 25 min). It is at a distance of about 25 - 30 Mly from the Milky Way, and has an apparent magnitude of 10.6. Its diameter is approximately 87000 lightyears, making it smaller than our own Milky Way. From earth, its size is 9.3' x 2.2'. It is uncertain wether this galaxy has a central bar. We see the galaxy almost edge on (78 degrees inclination), and the dust lanes give the center of the galaxy it's yellowish colour. Ngc 2683 contains a large number of globular clusters. Image details: data collected 22 & 24 January from my home observatory. L: 172 x 2 min (5.75 hrs) R, G: 30 x 4 min (each) B: 26 x 4 min Total integration time 11.5 hours Telescope: SW MN190 DS on a AZEQ6 GT Camera: ZWOASI174MM-Cool with ZWO LRGB filters, gain 20, temperature -20 C Guiding: OAG with ASI120MM-S, PHD2 Stacked and processed in PixInsight (click on the image to see a larger version)

There's really only one way to make sure: test the flats with your images. I think you will get more repeatable results if you point your scope at a (white) wall with indoor lights. LED lights if possible. Incandescent lights can give a too warm colour. Otoh, if you get good results with your flats, stick with your method.

Yes. The level looks good. 2 things to add: 1. Use a neutral object to point your camera at when you take flats. That is, as neutral as is possible. This makes subsequent processing a bit easier. 2. (And more important) make sure that object is evenly illuminated. The only variation in your flats should be due to vignetting and noise in the imaging train. Otherwise you're in trouble. Sky flats may not always work.

Actually, this came up on google when I entered James search phrase. Close but no Cigar. https://www.google.com/amp/s/www.popsugar.com/food/How-Measure-Spaghetti-41730124/amp

Ok, and with your lens I can imagine it will affect sky measurement. With my lens and lens holder, the sensor is shielded from the led on the esp board.

So, you have a cloud detector as well? I got mine as part of a separate weather station.

Depending on your focal length, and how critical you are, I'd say about 60 s. When I started out in this hobby, I managed 3 min subs with my 150pds (750 mm fl) on an eq3 goto mount, which I was very pleased with. Now I see that stars were elongated, and I wouldn't be happy with such a result. It depends very much on the mount (quality variance), load & balance, alignment quality, and probably sheer luck. Guiding has a threshold, but once you're over that you wonder why you waited so long.