ONIKKINEN

+1 vote for flocking. This stuff is much darker at an angle than Black 2.0: https://www.firstlightoptics.com/telescope-flocking-material/black-velour-telescope-flocking-material.html Cheap and easy to apply, highly recommended. The adhesive is strong once you rub it in place and let it be for a while, but you can peel it off and reapply it if you make a mess or leave bubbles and want to reapply. It also sticks to itself so you can eyeball the cut and have it overlap.

You pay for convenience in the form of a better focusing system and maybe included adjustable rings. In the end a simple 50mm finderscope turned into a guider will do the trick just fine. I had one of those but found focusing it to be very annoying, especially in very cold weather. Most will probably live with that. Next step up is something like this: https://www.firstlightoptics.com/guide-scopes/astro-essentials-50mm-guidescope-finderscope.html I have one that looks like this but is a 60mm one. The focuser is nice and the scope is sturdy, not much else to say and will definitely do the trick. But this one wont actually guide any better than the finderguider. The best option IMO would be an OAG. Guaranteed to have the best possible guiding when it comes to guiding setups. Not that expensive either really. If youre worried about the setup being a hassle, it really isnt that difficult. You set the backfocus correctly once and thats that, it stays focused. If youre still worried its going to be trouble you could get one that has a mini focuser for the guidecam (like the Askar one).

M31/M33 if i get an early night, if not will have to continue next autumn as they are setting soon. Orion if i get the chance to travel somewhere with decent skies down to 20 degrees elevation but this one is very weather dependent as its just too low M81/82 otherwise, will need a couple of nights to get IFN and maybe one night of narrowband. Might dump some hours into M101 too if im out very late. Depending on the weather this list applies to next years January too of course. 😬

The travel router is the source of the hotspot. You definitely dont need a sim or an actual internet connection with this method.

AFAIK you need windows 10 pro to use remote desktop features, may be wrong but thats what i understood when building mine. My mini-pc has the setup you are describing, a travel router that creates a dummy offline wifi networl when the PC powers on and i just remote desktop to that with the android app on my tablet. No actual internet connection required and also the only time i have had it hooked to a monitor was the initial setup. So looks like your home edition of W10 is the issue. Weird that it was sold like that since the point of most mini-PCs is to work headless.

My unit of the AZ-EQ6 is not a particularly good one, but its by no means a bad mount. The RA worm has a very steep part twice every period where guiding needs to be either predictive or very quick in exposures to not have a bad sub (several arcseconds over about 20s). The predictive PEC algorithm in PHD2 and 3 or 4 second guide exposures with an OAG seems to work all right with maybe a little hiccup every now and then. Total RMS error has been below 0.5" on nights of good seeing, but usually i see it hover around 0.6-0.8. All with an 8" newtonian not shielded from wind so i guess its ok, but many have better performance so im guessing i lost the mount lottery with mine. Would recommend, but beware that it is not a premium mount.

The difference is subtle, but the reprocess is better in many parts to my eyes. Particularly the parts on the trailing edge of M51 (opposite side to the companion galaxy) and between the trailing arm and the main body have propped themselves up. Dustlanes around the cores of both galaxies and bright blue star forming regions are better observed in the reprocess. Both are images to be very proud of in my book anyway!

Have a look at this site: https://www.teleskooppi.fi/ Looks familiar? I believe its the same company but with a different name, operating from Lativa (one linked marketed for Finnish customers). I have ordered from this place and got what i ordered, eventually. Items were marked as "in stock" and delivery should have been in a few days, but it took several weeks in the end which was annoying as i would have never ordered if i knew it would take so long. I was only notified of the lengthened delivery times when i asked them whats the holdup with the stuff i paid for. So it looks like a legit shop, but not one i would ever deal with again (or recommend others to).

Looks like amp glow creeping in from the top, i dont think it should be there with the Poseidon-C as the camera (this model and all IMX571 models) are advertised as amp-glow free. There can be a little bit of a glow with some models of IMX571 (like RisingCam) but yours looks much stronger than i have ever seen. This might be a case where you need to contact the seller/manufacturer and ask them whats up with that. If you take a darkframe, is it also visible? Should be, but there really shouldn't be any kind of visible pattern in any corner of the image with the 571 chips even in the longest possible exposures of 3600s.

If you're planning to take flats with your 533, you really dont have to worry about nonlinearity or sufficiently long flats exposures as the camera is very linear from 0 to max value. If your panel gives you 0.8s flats, then great use those. If it gives you 10s flats then maybe try to brighten it a bit, you will spend unnecessarily long taking those and there is no real reason to. With very narrow bandpass filters there may not be a choice, but generally no need for so long exposures with flats. With my 571 OSC camera i take 50 flats that are either 0.2s with a UV/IR filter or 1.1s with a narrow(ish) band triband filter. Neither have ever had any issues with calibration, even if the histogram is all over the place with reds being around 1/4th - 1/3rd of the way, greens bit behind middle and blues at slightly over half to 3/4ths of the histogram. As long as none of the channels are clipped to black or white, the flat will definitely work. Not sure what you mean with a lighter shade of black, but if you mean that the edges are brighter than the center (overcorrection), then you have not applied darks or darkflats properly (or at all). With your 533 you can use bias frames as darkflats if youre lazy.

Odd looking galaxy, reminds me of M110 with the dusty core. Nice picture and interesting to see the comparison to the older attempt.

Carbon fiber parts cost an arm and a leg so not that strange of a price. 0.5mm thickness is a little bit too risky imo even if its carbon fiber. Better than the stock one by a mile still i would imagine. The metal spider i linked comes in a 286mm variant, you could shorten the vanes yourself to make it fit. They are held to the center simply with 3 screws so you could remove them, shorten each by 35mm and refit them.

I just eyeballed it, will try with spirit levels next. I will orient the tube so that its perfectly level and adjust the focuser until the spirit level agrees that both the focuser drawtube and tube are even. I have a Baader diamond steeltrack which is adjustable in both pitch and yaw so it shouldnt be too difficult. By the way, try this spider if the replacement is also unworkable: https://www.teleskop-express.de/shop/product_info.php/info/p9317_TS-Optics-massive-Metal-Spider-for-8--Newtonian-Telescopes-D-223mm.html I installed that on my VX8 and it is a lot better. It only barely fits inside the tube so it kept the tube from collapsing, unlike the thin and flimsy spider originally. Pretty sure the VX8 and CT8 share the same spider so might be a decent fix for yours too.

Thank you very much! I have cropped a little bit off the edges where double diffraction spikes start to appear. Jury is still out on whether its backfocus, collimation, or tilt induced collimation relataed since it was the second time out with the scope after i swapped the aluminium tube to a carbon one, so the focuser could be a little skewed against the tube still. Sharpness in the middle was for around 2.2-2.5'' fwhm stars.

This article mentions the collision : https://earthsky.org/space/earths-night-sky-milky-way-andromeda-merge/ Whether its true or not is another thing as its based on the assumption that our galactic halo is similar in size to Andromedas halo. May not be the case, and difficult to tell our halo size from within it.

The RisingCam camera body is only 80mm in diameter, so shouldn't be any more extreme than your average F4 newtonian obstruction. T2 inline focuser and should work nicely, will need some DIY hardcore steel spider though.

Also could try to lower the Amount, 0.9 is the most i have needed. The problem with the invert-SCNR-invert workflow is that it removes actual magenta from the image which exists in galaxies (hydrogen regions). For this target not an issue, but worth keeping in mind that some images dont benefit from that.

Most beginners would do backflips from joy if they got this as one of the first attempts, so you are right i thought a couple steps too far ahead. Pretty sure i have seen this image before, if i recall correctly you had a wratten #8 and an aperture mask? And binning of course, to counter the loss in aperture. These dust spots and edge artifacts would actually be not that difficult to remove in Photoshop with some clone stamp tool, content aware fill, healing brush etc, especially if the image is turned starless with starnet++ first. Not sure if GIMP has similar tools but would imagine it does. Probably not something a complete beginner would know or figure out how to do but not that difficult either so perfect flats more of a luxury at that point (and if the sensor were bigger).

Since you mentioned M81 here i might mention that it was one of the first targets i tried with a 200mm newtonian on an EQM35 unguided. Didnt produce a great image but not because of the lack in guiding. This high in declination the sky moves so slowly that the beginner might forego guiding completely. The mosaicing thing could be trouble, i think you need to have more or less perfect flats to give yourself a chance of getting a seamless mosaic and the budget mak might not be up to that with its movable mirror and maybe not as sturdy a visual back as it should be (not sure about that but would imagine its not rock solid).

I think you have a terrific image here with a wealth of dusty stuff around this difficult target, but a number of things could be done to make the best out of it. First, an easy fix to the background that looks magenta: Invert the image and run SCNR green on it and invert again. Inverting an image turns magenta into green so SCNR green will work, inverting back restores the colours to where they should be. I think in this case you should not have done SCNR green since the result is too magenta (too much green lost). For what little i have tried SPCC on it doesn't nearly as often require an SCNR green afterwards compared to the older tools, so test that out too with the linear files. Second issue is with the sampling. Looks like you have drizzled the image x2? What you should have done is gone the other way, binned x2. That will provide a very good sampling rate for your kit, 2x higher SNR (4x compared to drizzled) but still produce a healthy 3000x2000px image with your camera. The higher SNR will also allow you to sharpen much further and control noise in noisy parts of the image. In short, sampling went the wrong way x2, try without drizzle and integer resample x2 after stacking. Other than these 2 points i think you have done a really good job with the processing, these dusty dark nebulae are very tricky to process. Your attached file was not linear so a limited amount of stuff can be done with it but i tried anyway, also i was able to sharpen the image more since i binned it x4 but doing it from the linear phase would yield much better results:

Now this is a challenge! Never even considered maksutovs but actually why not? Exposure times will be inconvenient but a beginner has 10 other things to worry about so they probably dont care.

Does this scope exist? Seems too good to be true. Long focus achromat maybe but the 2kg is suspect?

I think i would rather have coma that can be fixed later by saving money for a coma corrector than have an achromat that will always have CA. Fringe killer/wratten#8 will hide it, but there is no way to get rid of it fully without a compromise. We are also comparing a tiny 62mm aperture to 130mm aperture so i think the choice is quite clear. My vote for the ultimate budget DSO telescope setup would be an EQ5, with DIY onstep motors if necessary, and a 130PDS. If the imager chooses a dedicated astro cam instead of a second hand DSLR the sensor size will be quite small in budget models so coma will be less of a nuisance than with a large sensor. Second hand DSLRs are often the cheapest so probably not the case. Something that is easy to overlook when figuring out a budget build is that you really cant afford to buy cheap/what you dont want as in the long run the intermediate choices cost you money instead of saved it. You should budget the kit so that there are the least amount of compromises or things you have to completely replace in a few years or however long it takes for you to save money for it. If you buy the achromat but you want to replace it later because of the CA and the small aperture you are now in the negative budget wise for however much the scope cost. Maybe you can sell it and get 70% back, but that is still a loss and no guarantee you can get rid of it in a timely manner. So my advice is to look ahead for something you want rather than something you think you could get away with in a pinch. Of course it doesnt mean that you must save up for a Planewave CDK, but you get the idea - think 2 steps ahead when budgeting.

Big aperture (for the target), dark and exceptionally transparent skies, 1e- read noise makes the magic happen. Presentation resolution is also a forgiving 2'' per pixel so SNR of the stack is very good. But yeah, very surprised too that it turned out so clean so quickly.

55x60s per panel for a total of 1h50min with an 8'' newtonian: Took this before the M81-M82 image i also just posted, so i had a very productive night between the 24th and 25th. Almost makes up for the fact that the last 2 months were nonstop cloud. Mosaiced in APP which did a fantastic job requiring no fiddling with the seams. Linear processing in PI with SPCC, BlurXT, NoiseXT and a small resample downscale to fit my 1440p monitor better at 100% zoom. Partially stretched and then moved on to PS for the starless nonlinear stuff which included sharpening and denoising with various methods including NoiseXT of course and some local contrast adjustments. Very happy with it for such a short image that i previously didn't dare image because i was worried mosaicing is difficult for some reason.