ONIKKINEN

Noticed that you had included the stacked file in the post so i dont have to guess if SiriL or ASTAP gradient tools work on the file but can test them. Both of the files processed the same, in 4 simple steps. First BIN2x2 in ASTAP, then gradient removal in either ASTAP or SiriL, photometric colour calibration in SiriL, then SiriL autostretch with 1% blacks clipped. Both tools removed the gradient well, but i think the SiriL version worked better and without leaving the emptier half of the image green. ASTAP: SiriL: If you're looking to improve, i would recommend trying to learn a dedicated astronomy processing software for the early part of processing which for me consists of: Background extraction (gradients), colour calibration and a stretch. These are easy to do with SiriL, a free app that is somewhat easy to use for an astronomy software. Especially the photometric colour calibration and stretching in SiriL is really painless. For stretching these images i just clicked the autostretch button and pushed the blackpoint a little bit further afterwards, so 2 clicks whereas with Photoshop manual stretching its a bit more involved. The photometric colour calibration tool checks which stars are in your image using platesolving and then tries to match your captured colours to the measured colours of the stars in some photometric star catalogue to produce the best (realest) possible colour balance in the image. After these steps you have the groundwork of the image laid out, and can then adjust every little thing how you like in photoshop. I find that i do this early processing in a few minutes with SiriL and then spend who knows how long tweaking things with masks in Photoshop.

Gradients like this will be in every shot not taken in perfect darkness. I dont know if some pristine bortle 1 location is different since have not imaged from one, but at least from bortle 4 upwards its not something you can really avoid. There are a number of tools available for the job, some free some not. In SiriL: https://siril.org/ There is a background extraction tool that is meant to fix gradients, although for images like yours that have signal from corner to corner it is sometimes tricky to get working. Another option would be the linear gradient removal tool in ASTAP: https://www.hnsky.org/astap.htm that i find is sometimes easier to use than the SiriL background extractor. GradientXterminator i have found to be almost foolproof. It can remove pretty much any gradient (with some practice), but costs 60 USD so a bit pricey for a plugin with a single use. Astro pixel processor and Pixinsight have gradient removal tools too, but both are quite expensive.

I have found this to be almost unusable in cold weather = almost all the time for me. The action freezes/gets sticky easily and it gets difficult to operate. If i try to use it with one hand it just loosens itself from its threaded connection to my coma corrector. I have to grab the body with my left hand and then unlock the clicklock lever with my right to use it. I just went back to a simple 1 screw compression ring adapter from TS. Not recommended for folks who live in winter countries (-5 or colder maybe). Works well when warm though.

Thats a very good price for what looks like a quality piece of kit. My summer break from astro is 4 months anyway so might as well order one at the end of the season.

Is it the helmerichs carbon tube? Looks very nice. How long was the wait for it? i read somewhere that the pandemic has impacted the production times for these somewhat.

Hows the focuser then, any wiggleroom or unwanted movement if you try to grab the camera while its attached? Focus position is less important, as long as its close it shouldn't matter this much.

You get a ring like this when you move the camera between taking your lights and flats whether intentional or not. Solutions to that problem: dont touch the camera before taking flats or fix the mechanical issue causing the movement. The mechanical issue i would assume to be in the focuser. I am not familiar with your scope but just looking at it online i see that the focuser looks pretty good so maybe not. Could also be some other adapter/thread or mechanical issue somewhere else in the scope. Basically your flats will only work if the entire optical train is exactly the same in your lights and flats, and if not you get these artifacts.

Showercap, DIY a cap from cardboard, dustcap that fits your tube etc. My VX8 came with caps to both the front and back end of the tube. Doesnt have to be fancy, nobody will notice it in the dark.

Insane. I thought this was one of the least offensive hobbies out there and cant really think of any reason why someone would act like this... Some anti-science folks perhaps? Or just good old traditional crazy.

Well, the easiest solution would be to take calibration frames. Especially flats are very important, and its really not something that's optional in the long run if you want to get all the data out of your images. For some targets omitting flats is not a big deal, like when the target is small enough to only be in the center of the image but for most targets not taking flats means you will have serious trouble getting a presentable image in the end. If you dont want to take calibration frames for some reason you can just stack without the script. Its a bit more involved but nothing you cant learn in an afternoon of playing around with it, check this tutorial out: https://siril.org/tutorials/tuto-manual/ If you follow this tutorial but dont have calibration frames, you need to skip all the parts that have anything to do with them. Without flats you will also need to skip the background extraction process, as it requires your image to be reasonably flat to have a chance of working. Basically just: 1) convert the CR2 files to fits using the conversion tab. Click the + icon and select the images you want to include for stacking. Click "Debayer" on and give the sequence some name and press convert. 2) Register the frames (align them) in the Registration tab. Registration method can be left to Global Star Alignment (deep-sky) and Registration layer is best put to Green, as that has the highest signal to noise ratio in a colour camera. Just click Go register and Siril does its thing. 3) OPTIONAL: Use the Plot tab to inspect the frames and remove the worst ones. I would recommend doing this but its not strictly necessary. I dont have a strict rule on what quality must a frame be to include in stacking but i would just remove the clear outliers. 4) Stacking: You can leave most settings as they are and use Average stacking with rejection, Normalisation as Additive with scaling and Rejection as Winsorized Sigma Clipping with values 3 and 3. Doing the above will stack your frames without calibration of any kind if you must do that for some reason, but i would recommend you take calibration frames as part of the normal workflow as soon as possible.

Its worth it to try to get Siril to work for you and it doesn't really take that much getting used to. The easiest way is to use the premade OSC preprocessing script found in Siril. Just create a folder on a drive that has plenty of free space on it (and make this the "home folder" for Siril), create 4 subfolders named lights, darks, biases and flats and then put all the raw frames on these folders and click the script. Siril converts your CR2 files to .fits files and then calibrates them and stacks them. It really is that simple. Check this tutorial if it still doesn't make sense: https://siril.org/tutorials/first-steps/ If you want to have a drag and drop kind of experience like with DSS you can use Sirilic, which uses Siril to do the stacking but with a simple to use graphical interface. Check it out here: https://siril.org/docs/sirilic/#the-first-steps-with-sirilic With Sirilic you can do lots of things you cant really do with DSS, like removing background gradients per subframe (subsky) before stacking which helps a lot if you had an unusually strong gradient for some reason.

I would love to see it, whether its trouble for astronomy or not. Also, since i live at 60 degrees north, betelgeuse is always low in the sky or not visible at all, so i would mostly dodge the worst negative effects. Since its so far away i doubt it would have any observable detail other than a very bright star for years and years. During my lifetime? Dont know. Someone more knowledgeable on the supernova remnant expansion rate could probably answer that.

2x2 panel mosaic with an additional center panel for stitching the panels together. 60x30s per panel, except for the center which was 10x30s so in total 2h5min of integration. Shot with a RisingCam IMX571 OSC camera in a VX8 riding on an EQM35. Captured last august and the image had some star shape issues due to guiding, focuser slop and a poor quality baader M48 extension that did not thread properly so i had to reduce the size quite a bit. Stacked at 0.5 scale in APP and then further binned 2x2 as an attempt to hide the issues. Further processed in Siril and Photoshop utilizing Starnet++V2 for some minor separate star layer, background and galaxy layer tweaks.

I think you can drop the settle timeout and min settle time to much lower, like maybe 10 and 10 seconds. Your guiding looks pretty good and stable so i dont think you benefit from having the times be so long. I am not sure however how to change the settling limits setting. I would assume that its the 1.5 pixels you have set in NINA but the guide logs say otherwise. Never had this issue myself so not quite sure how to fix it, but this doesn't really make the dithering fail and just prolongs the settle time unnecessarily so not the main issue here. If dithering failed for some reason and its not apparent in the logs you can see it if you blink the frames in Pixinsight before registering them. Just blink a bunch of the frames and you should see a very obvious sudden jerk when dithering happens and if it does not happen well then dithering did not happen for some reason.

To me it looks like the dithers do happen on schedule and like they should. The log says your settling has failed, but i dont think that has to do with dithering success but is just the result of your settings. You have here the dither spike as it should in the directions ordered. The "settling failed" notification is there i think because you have a high settling time of 120 and strict settling limits. Not sure why your settling limits in the log appear to be less than 1'' but they are set as 1.5 pixels in NINA which would obviously be a lot more than that 🧐. I dont think this has anything to do with your issue, but this does waste 55 seconds after a dither. Im pretty sure NINA starts the next exposure only after PHD2 informs NINA that settling has completed, and since it fails for you every time it has to wait the 55s you have set it to in the settle timeout setting.

.html file format? Something went wrong, its supposed to be a .txt file

I cant see the problem in the raw subs. Also cant open the .xisf files so cant check the masters, but from the looks of your screenshot it does look like walking noise. It could also be the result of some funny sigma clipping issue where a bad sub is chosen as the reference by the stacker and so a lot of good data that deviates from the bad sub gets rejected in the end. I had this happen with deep sky stacker once, but not sure if its all that common of a problem. Your dithering schedule looks good, i dont think i would bother dithering more often. I dither every 10 subs when i shoot 30s ones, so every 5 minutes as well. I also dither in RA only and it still works well like this so not sure whats the problem. Can you check your PHD2 logs and see if the dithering actually took place? And if it did, how many pixels was the dithering set to. If your dithers are very small, like maybe 1 or 2 pixels i think they might not work that well with OSC cameras.

Hmm, for some reason i did not notice that the original post had a link to the stacked file... Well, anyway ran it through Siril and some photoshop fiddling afterwards: Background extraction as a first step to the linear file worked very well and the image is perfectly salvageable. I stretched it a bit too far here, but this is a quick edit that shows you can work with the data without flats in this case, if necessary.

Take new flats with the same focus position and stack with those. Set the lens at the same focal length and get it to infinity focus either by using stars or something far away in daylight and then shoot the flats. You can take a few different sets of flats with slightly different focus and focal length positions and check if one of them works. I would say its almost certain you can take flats that are much better than nothing and you can salvage the data. In the future try to shoot flats before the battery runs out, they are almost as important as the light frames themselves and you really do need them. If you dont want to do that for some reason, or cant get them to work properly you can try the background extraction tool in Siril (free). It doesn't always work like i want to but it will definitely help with your vignetting here. I ran your pic through it: The quality is not great because i just used your cropped screenshot JPEG, but it still worked a bit. Would expect it to work much better with the linear 32bit file straight off the stacker. If you try it out, i would recommend trying out Siril for other processing too, its much better than manual slider fiddling with GIMP/photoshop.

Hmm. Not going to hold my breath on this estimate, if the schedule of JWST has taught me anything. Maybe RST(?) will become as famous as JWST if it gets delayed for half a decade too?

Tennis is a hobby that can be as expensive as you want it to be, so i think the comparison to astronomy is quite good. Just renting a court and playing with a friend is not really that expensive, even if you do it a couple times a week. Equipment doesn't have to be top tier, really any decent racket and balls will do. But the thing that is expensive is the lessons you will probably want to take, if you have never played tennis, and this is quite expensive and not something i would want to pay out of pocket. I used to play tennis and i got the feeling that there were the casual normal players and then the super enthusiast i-must-get-better types of players and the teaching was mostly focused on pushing everyone to the latter category. There was also a bit of pressure to take more lessons and make tennis my only hobby, which it wasn't at the time so i just quit in the end. I do get the feeling that tennis is a bit of an elite sport if you take it far enough, but if you just play with friends casually then not. Actually come to think of it the logic applies to most sports hobbies i can think of.

Hmm, for new scopes there isn't much to choose from at this price point. Looking at SCTs you could get a 6'' SCT but honestly i would think the RC6 is a better performer if it held collimation. You could get a 200PDS with money left over for a good coma corrector and some other bits and that would make a pretty fast galaxy scope, but since its a newtonian you would still have to deal with keeping the thing collimated and possibly remedy some other newtonian issues. For used scopes, well anything goes since prices are not set in stone. If you do have a deal on a C9.25 that you could get for a price you like, you can use it with the 0.63x reducer with your current camera, provided that you bin or sample accordingly with other means, like super pixel debayering. So if you dont want to upgrade your camera for other reasons, know that you dont really have to. With the 0.63x you would still fit M33 comfortably on the 269, and everything other than M31 will be smaller than this so i would say its good to go.

What sort of budget are we looking at here? What mount will the scope be put on, and where (observatory/traveler/backyard etc)? Not sure how to advice without knowing these first.

Have a look at Siril: https://siril.org/ Its free and easy to use (for an astronomy software that is...). You can use it to preprocess and stack your images, but also do some post processing. Stretching and colour balancing especially in this software is just a couple of clicks, and will definitely be easier to do than manual fiddling with sliders in GIMP/Photoshop/some other non-astro software.

Love it 👍. Rich backgtound too. Holberg IX actually has some nice detail and there seems to be a faint background galaxy everywhere i look in the image.