ONIKKINEN

Before jumping to conclusions on sensor tilt you should attempt to eliminate all other sources of tilt. This could be focuser tilt or collimation (really these 2 are kind of the same thing). Its not a stacking problem, Siril has some fancy algorithm that will twist and turn every sub to match the reference frame, so all problems in a stack are things that are due to some issue with the scope/kit. That said, adjusting that tilt away can be tricky so up to you whether you can live with that or not. BlurXterminator would certainly fix that, but it kind of costs an arm and a leg since you also need Pixinsight so probably not the solution you were looking for. For your guiding its hard to say where the issue is without seeing the guide log. If you want to you could share the guide log for us to look at (just drag and drop it to the attachments, same way you do with images). * Based on the image i would not actually bother tweaking anything, looks good. You can easily make things worse with tilt adjustments.

I'd say this is a possibility. My issues persisted even without the hand controller plugged in, so there is a chance the alignment model is stored somewhere on the mount head itself.

What does the raw recording look like? Check whether it has this banding or not to rule out capture and camera issues. If you captured as .SER you can download SER player to look at the recorded video. Whether you have banding or not, check these settings: If you do have actual horizontal banding, try enabling the Row Noise Correction option, and of course try to fix the issue for the next time as your camera really shouldn't have any issues with banding at all. If you dont have banding in the raw recording make sure this option is off, as it can actually create the bands if you have it enabled when there is no banding. @Elpsuggested the alignment points, which is also something you need to see to. Its not apparent from your screenshots whether you had them or not, but you do need them.

Sorry, dont know anything about EKOS/Indi, but something like this has happened to my EQM-35 and AZ-EQ6 when using NINA. So there is a chance this is a Skywatcher thing and not a software thing. For me the weird wrong way slewing happened randomly and wouldn't go away within the night it happened. I ruled out different things and was left with only one option, the mount itself being confused by sync commands from NINA creating a bogus pointing model of some sort. At the time i used the USB port on the hand controller as a way to connect the mount to the PC, and a temporary fix was to factory reset the mount through the handset. Most likely not helpful for your case, different mount and control setup and all but thought to mention that a very similar thing happened with my mounts.

Im getting a different number for the factor, here is how i calculated mine: For our scopes we get a multiplier of 1.47 times already, your Esprit 150 has an aperture area of 17671 square mm, my 200mm aperture newtonian with an obstruction of 70mm and mirror coatings of 97% (OOUK Hilux coatings) is an effective aperture area of 25937. I went ahead and checked 3 subs from all my nights, 1 from the beginning one from the middle and the end and got an average SQM of 20.73 for the UV/IR nights and 20.43 for all the nights. I think the UV/IR data is doing most of the work based on the weighting calculations from Siril's plot drawing fucntion so lets call it something like SQM 20.6 as the average. So with an SQM difference of 0.77 multiplied by the 2.5x per magnitude factor we get a 1.925x increase in required integration time. In the end we get my baseline of 25h * 1.47 * 1.925 = 70,74h. So you would have to image for 70,74 hours with your kit and sky to reach the SNR of my 25h image, in theory of course. Not sure how well practice would follow this theory but safe to say your conditions would require significantly more integration time than with mine. If you got some pristine moonless data i think it would not require nearly as much time since a 70% Moon probably adds somewhere between 0.5-1 magnitude to the sky if not more. Doable, since you get twice the data with 2 scopes at the same time.

An absurd number of galaxies, great image!

If you see only white and no detail you need to lower your exposure time. The Moon is very bright so youll use something like 5ms for capture.

This actually looks pretty good. If someone is picking up the hobby from scratch, then this thing covers your imaging camera, guiding, and control all in one and that price tag is not that bad either. That is if it really is 2000 USD (probably at least 3000€ here, yay taxes).

Yours is quite nice too, those fainter spiral arms are a pain to pull out of the noise and here they are readily available. I think we could calculate an "equivalent time" between our scope/sky combos to see how big a difference there should be in SNR. Purely in aperture my 200mm is around 50% larger in area (roughly considering the obstruction and reflection losses from mirrors) but our imaging scales are almost the same (mine is 0.76''). The skies mine was taken from were probably around SQM 20.7 on average for the 7 nights i spent, some nights better than 21 and a few closer to 20, and integration time needed to reach some chosen SNR increases by roughly 2.5x per magnitude of sky brightness increase. So if you want to crunch the numbers you'd only have to figure out your sky brightness using ASTAP's sky quality measurement tool and then plot in the numbers to see how many hours would you need to reach what i got in 25h.

Isn't there a downloadable plugin for solar system objects in new versions of NINA? Check the plugins tab, it will be there if it exists. Cant check for that myself as im using an older version of NINA, but i am 90% sure i saw a plugin like that when i last checked what was available.

Looks like a shadow, or shell of some kind within the PN. Bits blown off the star prior to becoming a PN maybe?

I think my magnitude record is in the 22 region, in my last year's 35h M81 image. Skies in the location i use are between 20.7 and 21.3 depending on whether we have snow or not so going much further than that might not be too realistic.

You can also take flats indoors by pointing the scope at an evenly lit wall or a tv showing a white screen (and a t-shirt). I did the latter a few years back and it worked ok.

Thank you! There is always this thought at the back of my mind "what if it were better/deeper still". So i have no trouble justifying the hours to try and chase that. I do think there is room for improvement, particularly in Ha because the Triband + OSC combo is very inefficient at capturing it (wide 30 ish nm pass and only 1/4th of the sensor). I reckon just a few hours of proper mono Ha will beat the current triband data. The luminance aspect i am not so sure about. Part of me is excited to see if new faint background galaxies emerge from the noise, or if more stellar detail can be resolved in the galaxy. If the image doesnt improve much, well thats a problem for future me.

Sure is a humbling hobby. There are countless objects in the image that are not in any catalogue, and this is a very popular imaging target so its strange to find so many of them. Many of those faint fuzzy spots are older than the Earth, all in just a single degree of field of view.