Gumminess8083

I do use multiple stacked subs, usually I take 50 calibration frames per type (you can find a folder with the stacked masters at the same link). I only shared one per type since I am running out of space on my GDrive... As for the flat frames duration, I was taking sky subs and had a hard time taking them, as the sky was too bright. I did try retaking them today indoors using a tablet, but the patterns were still present (and the light was too dim, so I had a hard time getting any flat frame with an exposure time below 30 seconds at 200 gain). Since I've tried everything, I might as well redo the whole procedure using a new set of flats with a longer exposure time. I have moved the optical train, so they won't account for any tilt or dust bunny, but they'll at least fix the artifacts, hopefully... I'll also try stacking some uncalibrated light subs, just to see what comes of it. Update: I tried stacking some uncalibrated lights, and the patterns seems to be showing there as well, so the problem may really lie with my underexposed flats... I'll try taking some more and run some tests

Thanks for your reply and for sharing your experinece! Unfortunately, it seems like this doesn't hold true for my flats... Here you can see that the integrated and calibrated images seem to present the same pattern as the flat frames, almost as if it was introduced by the flats themselves (keep in mind these images have been locally normalized, hence the gradient going from right to left—I used an O frame as the reference—but the problem is still present, even when I skip that phase). If it's not asking for too much, I have uploaded some of my images to the following link: https://drive.google.com/drive/folders/1veeZFJm2dMvpqpiGXjTFDKqWJePYP2CA?usp=sharing Is there any chance you could have a look to see if anything strikes you as different from your data? Just in case it changes something, I've been working following this tutorial/workflow for narrowband data: https://www.chaoticnebula.com/workflows/

Hello Adam, sorry to resurrect this old thread! I finally got around to imaging some targets and I am indeed suffering from some of the problems you mentioned regarding the flat frames (similar to those mentioned in the linked thread). I tried taking them under various conditions (sky flats, phone screen, laptop screen, tablet, ...) with various gain and offset settings, but they alway come out looking weird (not all filters present the same patterns. For example the OIII filter seems to be perfectly even without any artifacts). I tried changing the settings around and following some suggestions I saw online, but the results always comes out looking like this... I'd be grateful if you had any recommendations of things I can try out!

Stuart did in fact message me yesterday with a link to his video, so I'll have to give it a later today! Just in case, I did notice that my redcat had these screws: Since in the imaging train these come after the filter wheel and just before the connection to the scope itself, could I possibly use these to try and fix the tilt (provided it's actually caused by the camera and not the cope itself)? Unfortunately this would prevent me from using Stuart's method, as the tilt adjuster is connected directly to the scope and it cannot be removed, as far as I know

This is my imaging train, as per what was written in the ASI camera's manual (excuse my unorthodox autofocus mounting mechanism 🤣) You are correct in assuming that the camera is threaded directly into the filter wheel!

@malc-c@StevieDvd Thanks for your help! Not sure which of the two things you recommended was the correct one, but now everything works!

Still windows 10, unfortunately, so no luck there. I'll post some pictures after lunch, just to show the error I get (connection timeout, aka, the mount is recognized but times out when I try to connect to it)

Unfortunately this picture was taken with a completely different camera (my old and now defunct Sony a6000), so it was only meant to verify whether the problem lied with the scope or the new camera (ASI294MM PRO)/optical train. I'll try to run some new tests as soon as I get a clear night

I did install it a few months ago, since my EQMOD cable required the same driver to even be recognized

So, I am upgrading my rig to use shorter cables, and, since my mount supports direct connection to my pc via usb (bypassing the hand controller), I decided to try using that. I used to connect my mount via a specific EQMOD cable, but, since the one I own is too long (1.5 m), and since getting a new usb cable rather than an EQMOD one is way cheaper, I decided to go with that. Even though my mount was able to connect to my pc without problems with the dedicated cable, now that I'm using an usb one, I seem unable to get it to work... Device manager recognizes the comm port as prolific COM3, but whenever I try to connect to it via the EQASCOM toolbox, I get a timeout error. I even tried changing the baud rate to no avail. Comm statistics gives me the same timeout error, despite at least recognizing the port. Could someone help me sorting this out?

Thanks for the suggestion! As soon as I have a clear night, I'll try taking everything apart and putting it back together to see if it makes a difference

https://drive.google.com/drive/folders/1SasrJO-5gHq4gyVQnYGWShdAhXL5uB4d I have uploaded here another picture I took with the same scope but different camera and shorter image train (no filter wheel). This does seem to have some tilt as well, but not in the same way (?)

The only moving parts are the spacers, camera and filter wheel. The redcat does have a built in tilt plate, but using that would force me to keep the camera in the same orientation at all times. I would love to run more tests, but the forecast tells me that it's going to rain for the next 2 weeks

Thanks for your replies, everyone! I'll keep shooting them at the end of the session without fussing too much about th edetails then

Thanks for confirming my doubts and for letting me know how to do that! In your opinion, would I be better off trying to fix the problem myself, or should I contact ZWO support and ask for a replacement? (I bought this from a third party reseller)

Ok, so, I recently took these images of the heart nebula and, while processing, I realized that some stars were oval-shaped, but only in the bottom left corner of the image. Top image is the bottom left corner, bottom image is the right corner. I am shooting from a Redcat 51 through a ZWO ASI294MM PRO and a ZWO filterwheel with Astronomik filters. If it matters, I'm also focusing through an autofocus motor. In this specific case, I was shooting narrowband, but I have also included an image I took with my green filter (to add RGB stars to the final image), and the problem seems to be present there as well. Sample images; all of them have this same problem. https://drive.google.com/drive/folders/1m8M4SOKaKj0EK6-BjCPDDdFMCPIhYcfy Could someone help me figure out if this is caused by sensor tilt or some other factor? Thanks in advance!

Hello everyone, how should I deal with flat frames when using an autofocus motor? I usually take my flat frames using NINA's flat wizard, but, since I frequently run autofocus sessions during my imaging sessions, I don't exactly know what my focus was during each specific image. Should I keep track of all focus values throughout the night and take separate flat frames for each of them, or can I just eyeball it and take some flat frames at whatever focus value the scope is at the end of the session?

Huh, I'm not too savvy on this sort of stuff, but this is kinda puzzling, now that you mention it... Maybe I will open a separate thread on this subject later today, although I don't even really know how I would phrase the question xD

Thanks for your reply and explanation! As far as I was told, the minimum value should be above 0 when you integrate all your darks using a minimum function instead of average. This is my result when I stack the same files as before but with a minimum function: Does this look correct, or should the minimum value still be above 0 even when integrating the darks with an average function? For context, I'm shooting at 200 gain and 2 offset- PS, thanks for the heads up about the FITS header. I didn't know it included such things! edit: these were the settings I used to stack my darks this time around:

So, I was just starting out with my dark library for my new camera (ZWO ASI294MM PRO) and noticed that some of the frames had these effects at the edges. Upon doing some reading, this appears to be amp glow, which is totally normal. My problem is the following: What you are seeing is an integration of multiple dark frames (around 40, average without any normalization). In a single frame, the only thing you can see is that "sunburst effect" on the right, while the one on the left is only present in the final integration. Furthermore, in the integration, you can also see some kind of light "glow" at the bottom of the image. Is this some form of light leak? I have uploaded one of my dakrs and the integration here: https://drive.google.com/drive/folders/1u74qVQrwNeKHUZ4R-xrFOFRhbHjOmHZC Thanks in advance for your help!

Just got my camera and ran some tests! Apparently, with gain at 200, as Adam suggested, it looks like offset can be kept pretty low. This is what a stack of 13 bias frames with 0 offset look like, so I could probably get away with just bumping my offset up to 1 or 2 As for the chip itself, might I bother you, @Adam J , for another question? You mention some paatterns being evident in the flats when taken at lower gain values, so I was wondering what these would look like, so I could try and run some tests to see if I can, by any chance, lower this value without running into any trouble!

If I'm understanding your post correctly, since I am actually using a 250mm redcat, I should probably consider going with bin1 rather than higher values, correct?

Thanks for your reply! I bought everything from a third party reseller, since import fees would have been too high otherwise... I got the standalone camera + filter wheel separately, and then the lrgb filters directly from Astronomik's website, so I'm not sure if they come with masks, or if I'll even need them, since they are 1.25" pre-mounted

Thanks for the detailed explanation! Even though I'm still a novice and not very familiar with all the intricacies of how cameras work, I think I get the gist of what you're saying and will stick with gain 200 for the forst few sequences. In the future, I may test to see if I can go lower without encountering any problems, but I don't think I'm yet experienced enough to notice those probles, even if I do come across them...

Thanks for your reply! 1- Gotcha about the offset. I'll try using that method with Pixinsight and see what I can achieve. As for bias, I'll be following Adam's suggestions 2- Good to know that I can bin in post and not care about it too much while shooting. I'm still learning about it, so I feel safer knowing that I can just shoot withou risking messing it up. 3- Temps here range from 0-10 in the winter to 30-40 in the summer, so I'll see what I can do to keep the temperature the same between shots and aim as low as I can go! 4- I'll hold off and try not to worry too much about this for the moment, then. 5- Thanks for explaining in detail how this all works! I'll keep this in mind when I get to shoot my first sequence.