ONIKKINEN

Probably, yeah. I try to image only at darksites and my 2 most common spots are SQM 21-ish and SQM 21.3 ish and gradient removal is still something that has to be done on each image. It will take a true darksite and a target at the zenith to not have any gradient, so almost all imagers will have to deal with that. By the way, you can doublecheck your actual sky conditions with ASTAP. Calibrate a sub, feed it to ASTAP, platesolve it, and then run the SQM tool on the image. It will tell you the actual sky conditions for that particular image you have taken, so if you are wondering whether or not your SQM-L is accurate or not given your neighbors new lights, you could check with ASTAP whether the data agrees with the other measurements.

Probably glow from Alnitak, or an internal reflection between 2 or more of the lenses in your flattener(?). Could also just be gradient from the sky, difficult to tell. But its easily removed with a good background extraction tool, i ran this JPEG through the background extraction tool in Siril and its definitely removable: Didnt pay much attention to the sampler placements, so some actual nebula signal was most likely also lost but run it on the linear file and you will get rid of it easily.

ASTAP has an SQM measurement tool that is quite accurate. Calibrate a sub, feed it to ASTAP, platesolve it and then run the tool. It will tell you the quality of your skies as measured from the data.

Microsoft took down the download link long ago but various third party downloads (like the one above) still work and ICE works like it always did. Astro pixel processor is another choice, but its not free. There is a 30 day trial for it though, so you could try it out first with some datasets that you have lying around. You can rent it for 60 USD (i think it was USD) + VAT for a year, or buy it. PIxInsight is also an option, but that costs an arm and a leg. APP is very slow with processing and will take quite a long time to process datasets with hundreds of subs, so not sure i would recommend it for general use if you take lots of short subs but the mosaicing does do a decent job when you figure out which options need to be ticked for each step of the way. Recently i took a 4 panel mosaic of M31 and it took lots and lots of attempts but in the end it was able to stich all the panels together with very little to no visible seams anywhere so it does work quite well for mosaicing.

I recall reading that Shapcap pro polar alignment somehow takes cone error into account in its calculations, cant point to any writing about that though. I do have significant cone error in my AZ-EQ6 with its axis of RA rotation being nowhere near 90° to DEC and also in my newtonian with its rings/plate/mangled tube. I guess i have at least a degree, probably more. I always aim for 2 arcmin PA or better and in the end PHD2 agrees with that number pretty closely. Usually the measured drift is between 0-8 arcmin at the end of a session so sharpcap does a pretty good job of it.

Great M33! Do agree with the magenta thing though, but that could also be just the chromatic aberration that makes the image appear more magenta than it really is when the stars grab ones attention, but probably a little bit too magenta still overall. How did you colour calibrate the image? I recommend photometric color calibration in Siril (and an SCNR green if necessary) or the manual color calibration with a chosen white area. You would have to know which star is roughly white to do that accurately though, sometimes calibrating on the core of a galaxy gets ok results also.

Cant offer advice on the VX12 specifically, however i do have a VX8 and assuming they are built the same way (looks very much like it from images) maybe some of my experiences apply. For imaging, short answer: dont. The tube is made of very thin rolled and crimped aluminium sheet that will guarantee there will be collimation issues because the tube itself is buckling under the weight of everything attached to it, and this is with the 8 inch, i would assume its no better (probably worse) for the bigger model. You can reinforce the 8'' model with some AC tube clamps bought cheaply at hardware stores, but the 12'' is much bigger and there may not be such sizes easily available although would be shocked if it cant be found on amazon. Another and a better option would be to ditch the cheap rings and plate the scope comes with and install a longer losmandy plate on rings that are spaced out much further away from each other than the stock ones (the stock ones are very narrow so offer little in the way of stability for the length of the tube) although not sure how this would work with a dob, so maybe not an option. The focuser is only ok, serviceable for simple use and light loads, but add a heavy coma corrector, camera gear, or just bulky eyepieces and i think you will run into trouble. The secondary spider is also very thin and i found mine to be inadequate to hold collimation even within sessions. The weak spider issue gets worse of course when the tube holding the spider is buckling under load (my tube was never fully round!). For visual, if you have a heavy eyepiece train containing big eyepieces and a coma corrector, i think you will also notice a loss in sharpness with demanding work like planetary/lunar where tilt issues are most apparent. The VX series from my perspective feels like a good optical package put into the bare minimum telescope, so know what you are getting into when buying one. Its kind of obvious when you look at the prices of just the mirrors, they are like 90% of the price of the rest of the scope so it cant be amazing. Currently i have fixed all the problems in my VX8 by replacing the not so great kit with better parts (also a helmerichs carbon tube whenever i have time to install it). At this point the price tag is actually more than the CT8 would have cost so think of that what you will, perhaps the CT12 would be a better option, although it is quite pricy.

Yep, the 678 eats harddrive space real fast. With lunar i fill my 240gb SSD and a complimentary 128gb USB stick in no time at all and most of my nights out with the 678 are hard capped to available space, not the weather.

Maybe a delay would help, but that could just delay the timing issues a bit longer. Didnt try that with mine. The screen will turn off during exposures so will affect battery life only a little bit. There might have been a timer ticking on the screen, cant recall if that was the case now. The dummy battery 12v DC adapter would be the best option for that though.

70mm scope, DSLR, eyepiece projection? These are EXCELLENT for the kit.

Pretty sure its that extra second or so that the mirror takes when flipping up or down at the beginning and ends of an exposure that ruins the timings. NINA will think the exposures go back to back without delay and after a few exposures your actual exposure schedule and what NINA thinks is happening dont match and you get timeout errors. In live view the mirror is kept out of the way so the timings match.

Similar timing issues with my 550D, try this: Put the camera in manual mode with the exposure set to bulb. Turn live view on, and only then connect to NINA. Make sure that all delay shooting modes/mirror lock things are turned off from the settings too so that these dont ruin NINAs frame timings. When swapping batteries you need to disconnect the camera, shut down, and then replace and reconnect.

Will this laptop be left in the observatory as the "scope side" computer? If that is the case, i would recommend a mini-pc instead of a laptop. Less bulk, easier to power, no unnecessary display/keyboard/trim (that costs money and add nothing to the setup). You then control that mini-pc via remote desktop over internet with your home pc or a tablet if you want to be at the scopeside doing something.

If it really is geostationary, it will not be directly above the UK as the UK is nowhere near the equator and the equator is the only place you can have a geostationary orbit. It would be stationary somewhere to the south pretty low in the sky where the most useful imaging and observing areas are not. It could be geosynchronous in a way with a little bit of inclination but an orbital period of 24h. That way it would go up and down in the sky, occasionally dipping below the horizon (not good) and occasionally appearing near the zenith (great). I think that is overall less efficient so the best bet would have it be fully stationary.

Above zero in celsius is still pretty warm, even for the low thermal signal new models (533, 571, 585, maybe others). The camera will run at least 10c warmer than ambient so youre looking at a pretty warm sensor that will be difficult to calibrate. In places that actually get winter (at least -10c) you could get away with not cooling one of the newer models but still calibration will be tricky.

Assuming you have a tracking mount (if not, that is step #1) you should look into autoguiding as the next step. Tracking mounts dont really track all that accurately over long exposures, even good ones, due to periodic error in the worm gears. The ones that do have encoders built in and now you are looking at 2k at minimum investment. Autoguiding however is not so expensive and a simple finder scope and ASI 120MM combo will run whatever mount much better. You will need a computer to run the software, but if you have an old laptop lying around that issue is also solved. After accurate tracking is in play the next step would be a cooled dedicated astronomy camera to couple with your existing lens. These are pricey though, so your budget will determine if its worth looking for right now. Expect to spend at least 500 (€/£/$) for a used one, maybe double or triple that for a new one with a large sensor.

For the name: The longbow nebula. The little bits to the left of the main body look like a broken string and the main body of the nebula look like a bow with a bit of recurve on both ends. Recurve bow nebula sounds worse, so longbow nebula is my suggestion.

Looks like a shell of sorts to the right of HD209919, is this the PN? Hard to tell since it is so weak and diffuse, but a roughly circular cloud with a darker center as most PNs appear to have.

Is the primary dewing up when the scope is in use? Never had that happen on my 8 inch when using it, but it dews up when bringing the scope inside which is more or less unavoidable. For the front end you can get any flexible dew shield and cut it with scissors to fit your scope. Like this one: https://www.firstlightoptics.com/dew-prevention/astro-essentials-flexible-dew-shield-for-8-telescopes.html Just cut gaps for your focuser/secondary spider mounting screws to fit your tube. Its unnecessarily long otherwise so plenty of material to cut from.

@Phillyo I went through some failed frames of the last few sessions to see what was wrong with them (all but this is some mount hiccup) and found this: Looks familiar, a bit like yours from a while ago. Weird banding all around, blotches of colours here and there and a weird red to white gradient across the image. There was no external flash of light or anything at the time, the scope was very much doing its own thing in darkness not being disturbed. No clue what happened or why and have definitely not seen anything like this with my camera, the sub before this and after this are perfectly normal with none of this. My mini-pc too is a bit busted as it has been rained on and has crashed a couple of times after that. Also a USB hub in between the camera and PC, so many possible points of failure. But could of course be something in the camera at fault too. Will look out more carefully if this happens again, usually i just sort my subs based on their statistics and i never really inspect obviously failed subs like this one but just not include them in the calibration run i do after a night.

Colour calibration for this one was whatever APP made of it with, just saturated a little bit afterwards. Pleased with the result myself too, but it is a little bit blueshifted from what might be considered "real colour", whatever that means.

Are these narrowband, or broadband captures? Pretty sure its broadband, since the background levels are quite high in both. The mode1 shot looks a little bit too saturated to my eyes, plenty of areas in the actual nebula itself are clipped to white, which is obviously not great. But the mode0 shot also has these areas, just less of them. Both could use a little less exposure time so that you dont saturate the target in question. Stars will saturate to some degree always, so no point in peeping those pixels. There is a formula you could use (if you want to) to figure out an exposure time that i sufficiently long to bury read noise by a certain factor, for example 5x which is already very good. You multiply your read noise in electrons by the desired swamp factor, and square that result to get the target number of electrons per pixel of background. So for the mode1 image with 2.07e of read noise and a desired swamp factor of x5 you get: 2.07x5 = 10.35. 10.35^2 = 107e of background signal. Im not sure how much offset you have in these images, but i am guessing it is 250ADU with 25 offset, you will find better technical advice in the QHY268 specific thread for sure but that is my guess. Subtracting that from an area of the image with no nebulosity i get 655ADU, which with an e-/ADU conversion rate of somewhere around 0.5 (judging from the graphs, its not clear exactly what the number is) gets you 327e- of background signal so you could expose for a third of the time you currently do and still swamp read noise x5. Shortening the subs will help or remove the saturation issue but not have any real downsides, apart from having to take loads more of the subs since they are shorter. Storage is cheap these days and most stacking software are fast so not a big deal in my opinion.

Your Mars images keep getting better as opposition draws closer, excited to see just how good it can get when already there is so much to see! Your setup looks really funny with the giant tube on the modest mount. Kind of amazed the EQ5 handles the beast.

My opinion too of starless galaxy images are also something like this usually. I tried keeping the stars in M31 in there to give the eye some kind of pop to hold on to so that its not just a flat image, almost like a painting in many cases with starless galaxies. What would give the image more pop would be H-alpha, however my wallet disagrees at the moment. This will make a fine reference frame for future mosaicing if i do end up shooting Ha at one point though. Also, the framing is a little bit claustrophobic, could use some extra panels around the corners as the signal does go all the way to the corners in a diagnostic heavy stretched version.

Thank you all, opinion seems to be divisive between the 2 versions which is why i posted both. I tried processing so that i would have the best of both worlds, but no cigar on that yet. Either the milky way starfield suffers too much, or the galaxy is overstretched or requires intense HDR workflow to make the image work which i am not so good at to make a presentable image. This was the attempt. Not so much a starless image, but rather a "foreground removed" image with the view of Andromeda as it would be just slightly outside the milky way.