ONIKKINEN

The Asiair definitely wont use 5A on its own, at least not all the time, neither will the EFW, EAF or the camera cooler use that much unless you are constantly changing filters, focusing and deliberately cooling to as low as the camera will go and its very hot outside. Pretty sure you can safely at least half the expected load you calculated there.

Reduction, or rather not stretching them too far in the first place by separating the stars and nebulosity partway through processing, is a good thing IMO. Most types of images benefit from this, but not all. As an example i would give an image of M33 where it makes no sense to try and reduce stars by any significant amount since all the interesting detail is in the form of stars within M33 itself. (here i think even BlurXT fails to improve and rather makes it worse). I have a principle that bright stars should remain obviously the brightest points in an image, kind of like focal points for the observer seeing the image going "hey that thing has giant diffraction spikes and is big and bright, must be a big star". Generally an A is brighter than B in real life, so A has to be obviously brighter than B in the image kind of mentality should be kept in mind. An image has failed in my opinion when all the stars look roughly the same soulless blobs without any real colour (or the ability to differentiate the colour because of lacking saturation) to them and at that point star reduction has done no favours. There is also an argument that smaller stars are more real since they are actually point sources from our perspective, its just that blur added by the atmosphere, and the setup used smears them out to several pixels. Too much reduction is much worse than no reduction IMO. I disagree with this statement by quite a bit, the basis for all astrophotography processing that is not specifically stated to be art should be realism and its not too difficult to stay within the lines. Stacking is no different than addition of signal over time the same way a longer single exposure is, its just a necessary step since we cant take 10 hour exposures easily from Earth. Stretching is also a necessity, since there exists no display that allows you to display display the brightness differences found in space (or human eyes, which are incapable of seeing those anyway). I think there is a general range of acceptable adjustments you can make for cosmetic reasons and its obvious when you step too far into fantasy from a realistic looking image (complete star murder one of them), but who gets to decide where the line is? And we go back into square one, since everyone has their own ideas of an acceptably touched up image so in an argument with 10 people there might be 11 different opinions. So also kind of agree actually, but not because of why you think so.

Love to see a vibrant starfield with nice tight stars and sharp diffraction spikes with this target.

It is free. I have had better success with Siril background extraction than DBE in PI, but i am a beginner with PI so wouldnt have had time to learn DBE properly.

Try Siril? The background extraction tool in Siril can work with difficult gradients. Yours doesnt look too difficult, just have to mind the sampler placements so that the tool doesnt sample actual signal like the faint dusty parts.

How much exactly are you willing to spend? There is no single setup that can be used as an example without a specific sum of money in mind. Are we talking 2000£/€/whatever after the mount or are we talking less? Are we talking 5k for the scope and stuff? No upper limit, but there is a reasonable lower limit for everything you want to do and likely you will have to take some compromises on the list of stuff you want to do. Also how much do you want to do planetary and how much you want to do DSO? Scopes that excel at both are either very expensive, difficult to use, fantasy, or a mix of all 3.

Did you take flats and did you take them directly after the session (or is your setup permanent so that you dont have to fiddle with gear every time you set up)? And if you did, did you calibrate those flats with matching darkflats while also calibrating your lights with matching darks. Another option would be some kind of local light source reflecting/leaking into somewhere. This kind of darkness surrounding M45 and then a sudden increase is definitely not natural and is some kind of aberration from your setup or your location.

In bortle 5 i wouldn't use a light pollution filter for broadband targets, and probably not in B6 either. Depends on the target, and the filter i would say. For broadband targets: Galaxies, reflection nebulae, dark nebulae i would not use a generic wide band light pollution filter because there is hardly a point (these targets radiate on the same spectrum as light pollution so blocking LP blocks the target = no point). For emission nebulae, you will see a significant improvement, but here i would rather use an emission line filter rather than a generic light pollution filter like a CLS type filter or an L-Pro. Coupling a UV/IR filter with another type of broadband or narrowband filter is not necessary as those filters also block UV and IR wavelengths, unless stated otherwise (few filters need both). Options for an easier to begin with narrowband filter would be something like the Optolong L-enhance or Antlia Triband RGB ultra which pass a fair bit around Ha and OIII (and the Triband RGB passes additional blue) and so dont require uber long exposures to make use of. If you want a more restrictive filter that ultimately results in more emission signal trough and less anything else you have options like L-extreme, L-ultimate and many others from Idas, Antlia, Askar etc (every manufacturer has their version). These more restrictive filters pass less light trough, so exposure times will need to be much longer. However there is a problem, the factory UV/IR filter in DSLRs blocks most of H-alpha so you will need to expose for really long and still not get much signal in the red channel. So for a stock DSLR i would not suggest using a very restrictive filter as the Ha layer will undoubtedly be very noisy even in long exposures. Oxygen III emissions in the green/blue colour will pass very nicely through a stock DSLR though so its not all lost. I would say dont worry about the CA too much, get a more restrictive UV/IR filter like the Astronomik L3 and forget about the CA as not much else to be done about it. Only very bright and blue stars will be significant trouble, and you can try to reduce that glow in processing later for instance by selectively desaturating the specific type of purple found around those stars or using masks and/or starless processing to not stretch those bright blue stars as much as the rest of the image (or simply the color fringe tool in Camera raw in Photoshop if you have it). Apart from the Pleiades there wont be many stars so bright and blue that you have to worry about. And even with the Pleiades you can work around them in postprocessing so knowing the limitations and that some processing tricks are needed you can definitely get a pretty image out of it.

The dark pillars and filaments are particularly stunning and sharp here, very nice image. Regarding PI and different image scales, so far have not been able to do that either with 800mm and 1020mm focal length mixed datasets that register just fine in Siril or APP. Maybe its some on purpose design decision in PI?

Affordable small doublets are often the first scopes new astrophotographers buy, so there is a lot of rose tinted review kind of thing going on where it looks good to most beginning users but those who expect true photographic apochromatic performance will be disappointed (for visual use these are more or less true apochromats). Realistically a fast doublet will always have CA even with premium glass. Even longer focal ratio doublets will have some CA too unless we get into very long and cumbersome f-ratios, you really do need a triplet if the goal is true colour free imaging with a colour camera that captures all of the visible spectrum at once. That being said, more restrictive filters are a good choice as the worst performance is at the far end of the blue and red spectrum (which the L3 cuts mostly). You can use a filter with your unmodded camera and i would recommend that for this case. Unmodded DSLRs still let trough a little bit of the purple/near UV wavelengths that the Astronomik L3 would cut off. The red side is not nearly as affected as the stock IR cut filter in DSLRs is quite aggressive already. The M31 looks just about what one would expect, i think the scope is doing a pretty good job with more normal temperature stars.

Its a fast doublet, so some colour is to be expected, but not sure if this much. You are imaging a group of extremely bright and exceptionally blue stars here, so perhaps the worst case scenario and its possible the scope is working as expected. You might want to add an Astronomik L3 filter to cull out some purple and blue with a colour camera, that one has a tighter UV/IR cut range than most other UV/IR cut filters.

Took another go at processing this to try and bring out the IFN: Looks dirty and noisy, but it is there. Still with the same 4h of data as have not had a chance to image since capture, surprised that there is so much in just 4h. Had to work for it though, as i used all the tricks i could think of: binning x4 as opposed to x2 of the original, processing only luminance from that to the point where the IFN is the least worst in terms of noise and stretch, resampled back to 200% or the original size in order to overlay that on a galaxy stretched image still at 1.51''/pixel. Some masking and eraser in Photoshop to selectively apply the luminance layer on just the IFN and the fainter parts of the image so that the galaxies dont saturate (would saturate with the IFN stretch). Stars added in last. Judging from this result with just 4h it should become a very nice IFN image if i manage to add a couple of nights more, but weather will be deciding that in the end.

I used to observe with my 8'' on an EQM-35, a very fiddly and weak mount that always lost alignment if i tried to spin the rings so i figured out some ways to make it (a bit) easier. I would figure out which part of the sky im going to observe in and roughly what orientation the tube would be in, then i would rotate the rings so that its the least inconvenient in all of the sky that i plan on observing at. Of course that means that the eyepiece is at an observable position only in about a third of the sky, but usually that was more than enough to have a look at different targets. Then i would return the axis manually to home position and do the go-to alignment from there. Now the eyepiece is probably in some almost unusable orientation but i only have to look through it a little bit to get the go-to alignment working. Finderscope was my friend here and sometimes i just used that for the alignment (if it was perfectly aligned, otherwise waste of time). I think its better to struggle looking through the eyepiece during alignment rather than during observation so this is the least worst option IMO. Or you can try doing what you're already doing, rotating the scope in the rings but as you know its very easy to knock either axis off and its game over. I did both but often had to re do the go-to circus because rotating the scope in the rings is sure to shift something in the mount.

Great tool, so far have not found a gradient it could not deal with. IMO better than DBE in PixInsight too, but that is most likely user error as have not had time to learn DBE as well as possible.

I had a USB powered dewstrap when i used a guidescope and it was way too hot, not that it mattered since it still wasnt very power hungry but a larger one might be. That one did not have a switch of any kind so full power all the time, you might find that the minimum setting is enough with yours as it only needs to heat the glass by one degree or so.

+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.