AstroDab3k

Ok, so I tried different software to stack and process it. The best results were coming from Pixinsight stacking and some basic processing, like ABE and MLT (I just started using this software ...and I'm loving it ) then Starnet2 and PS. In the final version I combined sessions with (where banding occured) and w/o filter (no banding, but still bad noise) with flats and darks, but I did not add bias frames (as suggested before). It seems that the bias frames were causing the banding issue. I'm yet to try the lights and flats only stacking to see if maybe there will be less noise also as suggested here. Here are the results so far. Can't decide which one I hate less

Thank you, I will try that too. In the meantime I decided to buy dedicated astro, but I'm thinking I will keep this camera and prime lens with low FL for some milkyway or extra wide field AP

Thank you for the steps. Yeah I failed miserably with the second session and this light leak, but I'm glad to see that this banding is removable.

I'm lost again I tried Siril (even PixInsight) and on stacked (or even raw fits) it doesn't do much unfortunately. Some very minor improvement. Below is the stacked image without calibration frames. Same result I have also attached the raw data, if someone wants to give it a play. https://drive.google.com/drive/folders/1gEaTDUTd687oGtpiHEd_auysU8_WqxPT?usp=sharing

😮I literally had to pick up my jaw from the floor... I tried it even on my first version with 2h data and it already improved by a lot. I never used this software but I think I will start from now on...are you using it for stacking too? or something else?

Ok I see your point. Assuming that I'm checking in correct place, the avg ADU for filter frames is 8978 (Session 2) 8533 (Session 1) and for no filter 12540. So basically filter is doing the good job, it's just bringing the 600d banding to the point that it kills the picture? I've done 4h+ of data and it's just increasing the problem rather removing :/. I didn't use the PixInsight yet, I'll see if this will help somehow

1. Stable DC supply 2. Well I tried both and results are the same 3. There is memory card in the camera (should I remove it if I shoot with Asiair?) 3. Yes and turned off (however with second session I forgot about it 🤪) 4. No dithering. I'm using Asiair App to shoot and I thought it's only possible with guiding (which I'm yet to upgrade) 5. Well, I'm using APP or DSS, no idea how to do this. I tried software ImagesPlus (found someone recommending this for horizontal banding in DSLRs) but couldn't improve anything, just introducing even more banding... 6. In DSS I'm using Kappa-Sigma clipping, but in APP I follow the standard ones

I've done 4+ hours in total with the filter and results was even worse (i.e. the horizontal banding was more prominent). I tried stacking in different software and also even without using any calibration frames (just lights). Same results. However I have done a comparison with shooting with and without filter (although I managed to shoot only 2 frames w/o filter). I took single frames and stretched them only to show the banding problem (see below). The no filter frames have normal noise patern which would be removed with more integration, but the fitler ones have regular horizontal lines pattern Session 1 Filter (single frame) Session 2 Filter (single frame) - dont mind the glow from the left, I forgot to turn of the LCD screen Session 2 NoFilter (single frame)

In my case, I'm 90% sure it's the wrong EOS M48 ring (I'm mean it's not even M48 ring, I had somethign at home that I modified, but I measured wrongly the thickness) no not really, I'm planning to do next session(s) without it. I have accumulated 4+ hours with the filter and all frames suffer from horrible horizontal banding, or maybe it's not even that. I can see that already before stacking when I stretch single exposure. First session had better seeing and it wasn't that bad but with second session and worse seeing, after stacking all looks like crap. I will upload images later today when I get back home to show what I mean. I tried two frames without the filter on the same object the same night, and after quick stretch in Asiair app I noticed that this banding issue is gone. I will need to dig into that a bit more. Maybe I have a "bad batch" filter and will have to return it. I'm a bit angry as I'm not sure if I will be able to recover anythign from this data, so 4+ hours of imaging gone

Thanks, that's a very good point. I see that there are a lot of conflicting opinions on many topics, but the best way is often to check by myself (as long as it's not related to spend money, then I prefer to do the thorough review ;-))

Thank you, will give it a try!

Thank all for very helpful insights! Allow me to reply in one post, but before that I captured some more data yesterday and I noticed that pattern already on single subs. At the end of the session I removed the filter and did 2 test shots. I haven't stretched them in the PC software yet (just used the ASIAIR mobile app) but I already noticed that the strange horizontal pattern is not there anymore, so I suspect that the filter is cause of troubles. Thank you Simon, I read about DSLR pattern as well and found that there's a free software called ImagesPlus that apparently removes similar issue with good effects, before stacking. I always crop after stacking but I saw that in APP there's an option to crop before, so I have to try this. Thanks! I used Flats, Darks and Bias. So far I read that they are always needed (especially darks), since the Canon sensor can get quite hot. What do you mean by subtracting this value?. Is there such option in usual stacking software? In terms of filter, it seems after yesterday session that it may be an cause of the problem. I read that it's recommended regardless of sky quality on emission nebulas as it brings the details significantly...but if this will cause this strange pattern, I will get rid of it (assuming that it's not a faulty batch) And for OAG, I'm still struggling with my decision. I read a lot about issues with differential flexure when using scope and a lot of recommendation for OAG even for lower focal lenghts. I found the OAG (also recomended in post below) from TS-Optics that would be part of the M48 ring that goes to camera and I could achieve the 55m backfocus. Pricewise the set-up would cost me similarly to the guide scope and camera (vs OAG + camera), at least where I live, but the downside would be that if I decide to upgrade to dedicated camera I will have not use for this OAG most probably. Thank you. I agree I didn't pay attention to turn off the screen camera and I noticed that there's some leakage/amp glow on the darks. Thank you! Yes, this is the same OAG I'm thinking about. As for the filters, I'm struggling a bit now whether I even need them for my sky quality. Thanks, I didn't think about simply cropping the image to remove the elongated stars, but on the other hand looking at my imageI would loose a lot of frame? Are there any downsides to flatteners (i.e. less light coming through?). In terms of scope, do you mean to point a star in the software or physically turn the scope slightly off? but then all this talk about differential flexure and suggestions to use the scope with rings instead of finder to keep it ideally with the scope. I'm confused now ;D, so much to learn 🙂 That's a great advise about using different stacks, I got fixated with APP after first use as it removed a lot of issues with removing vigneting, background calibration and initial stretching that I've had previosly using DSS and PS only, but I need to try other options, world belongs to the brave ones 😉 Thanks again to all of you for very helpful information, so many new ways to solve the problem and try which works best for my situation!

Hi everyone. I'm very new to the hobby and had only few images with DSLR + Lens and Star Tracker. I managed recently to purchase a nice new scope on a fairly good price from company TS-Optics. I've seen many good reviews about their refractors and apparently this is a rebranded Sharpstar with some minor changes. Anyway I wonder whether I set this up correctly. It came originally as in below picture However to put flattener in place I had to remove the two elements above (which is a pity as I liked the red accent). There was no manual with the scope so I hope I fitted out out correctly. Then I struggled to find place where to put 2" filter, and I had to disassemble flattener and put it in front of the glass. It was the only place, but I heard that it's always recommended to put it closer to the sensor, which in my case was not possible. Then I had some old T2 ring adapter to canon DSLR which I used with my dobsonian reflector. It didn't fit straight away, but I noticed it has some small screws which were holding the inner ring. I removed it and et voilá it fits now the end of flattener. I tested it yesterday and I found number of issues. 1. Flattener needs 55mm back focus, camera has 44mm and I thought that modified ring has 11mm (if I measure the thread/ entry to camera), but it seems I measured wrong as you can see on below picture, the stars are elongated from borders to center. If what I suspect is the case, I need to buy proper adapter. 2. Star colors. I know that L-eNhance does some strange things with color, but I thought it's only gradient which I tried to remove with flats in APP. However stars are still green/blue and I had difficulties removing the color. Is it normal with this filter or something wrong with camera? Should I take also exposures without filter? 3. The horrible noise on the right side of the image or actually accros the whole image, it looks like a smudge from left to right (I've seen the walking noise previously but it wasn't that prominent). Not sure if this is something wrong with my rig, or I just need more integration time and this is just nebulosity with not enough data. Any suggestions? 4. If I would like to add the OAG, how could I achieve the focus then? ZWO OAG has 16.5mm thickness and has m48 adapter to fit camera, but then I'll have more than 55mm? 5. Is filter in front of flattener creating some issues with data or not? Or should it always be between flattener and sensor, if yes what are the ways to attach it? I've been shooting with below set-up at ISO800, 180s subs. Bortle 4. Total integration time 2h48m. I used calbration frames too. My Rig: TS-Optics PhotoLine 60 mm f/6 FPL53, 1.0x Flattener, Optolong 2" L-eNhance, Canon 600D (modded), AsiAir Mini It was a very quick APP and PS processing, so maybe there's more into this data that could improve the image, but so far I see that there are some fundamental issues with data itself. Sorry for long intro and post and thanks for all the answers.