Stuf1978

Thanks, yeah I've read all the threads on cloudy nights hence aiming for flats greater than 3 seconds. I haven't tried flats with the sky yet but it is definitely something I will try. It's been a while since I read all the cloudy nights info so it's probably worth revisiting it. Double layer of a white t-shirt, I haven't tried a single layer yet but that's an interesting theory so it's probably worth trying it out. I'll probably get more time at the weekend to shoot various flats and see how it works out. I haven't scrutinised all the new flats yet but when I do I'll post up on here if I discover any issues. The other issue with shorter flats was more pronounced vignetting so they weren't correcting properly so I still haven't got a way forward for definite. However, it's early days with the camera and you always get teething problems to iron out with new kit. I haven't had a chance to stack with Siril as of yet but will at some point and yeah I checked every light frame and nothing was apparent. Isn't astrophotography wonderful

Edit, the issue was definitely flats related..... I think 😂 Managed another couple of hours on the triplet last night and shot several variations of flats. The ones without using a white t-shirt and using the flat aid with a target of 25000 ADU got rid of the banding but there were other issues. I think it will just be a case of experimentation until I find out what works with the camera. As an aside the data is much nicer to process than that from my old 450D

Beautiful image of a target that I've never seen before, great work

That's a lovely result, great work

Yeah I tried doing manual flats as Vlaiv suggested but still get the same result. I have been playing about with the original stack and the band can be almost eliminated with careful stretching. Part of me thinks it could just be gradient related as it's less than 2 hours of OSC data from a bortle 8 zone in which I imaged between 2 streetlights. Maybe more data and less aggressive stretching will sort it out?

no, it's unchecked

It's the first time I've stacked data from a dedicated astro camera so it could be all or none of the above All frames were taken at -10 degrees and at the same gain and offset value and the images were captured in APT. I will have a go at stacking the images in Siril and see if I get the same results and I'll try and share the files on here for others to have a play.

It's annoying as you can't see it in the individual subs, only the stack. I guess I'll just have to gather more data and stretch it less aggressively in order to get something from the image and hopefully try and minimise it in post processing.

Here is a stretched dark, nothing but amp glow. I've also tried just stacking the lights frames and it's also apparent in these so could be something that's happened during capture.

Nope. Although I said the issue isn't the flats I'm guessing it could still be a flat issue in that they should be calibrating this out.

Edit to my post above..... the issue isn't the flats. I've stacked just the light and dark frames and the band is still there 🤷‍♂️ The flats appear to be doing their job in the original stack as without them there is much more pronounced vignetting etc.

Thanks, yeah T shirt was stretched tight and held in place by an elastic band. I just wasn't sure whether this was flat related with it just being that dark band across the top of the image with the rest of image looking fine. I'll hopefully be gathering more data on this tonight so I'll try shooting various combinations of flats and see what happens. That's good to know you can get away with shorter flat exposures 👍

Thread hijak I've also just bought a 294MC Pro and last night was the first chance I have had to use it and I'm also having issues with calibration. I had read this thread prior to using it (some great advice here) and took a lot of it into consideration. So I shot the Leo Triplet and I gathered 39 x 180 second light frames, 20 x 180 second dark frames, 20 flats x 7 seconds and 20 dark flats x 7 seconds. All were shot at 120 (unity) gain and with an offset of 30, the flats were taken using APT flat aid with a target ADU of 25000 with a double layer white t-shirt and white screen from an ipad. The ipad screen brightness was turned down pretty low to ensure that the flat exposures were greater than 3-4 seconds as is recommended for this camera. I stacked/debayered everything in DSS and processed in photoshop. On first impressions it all looked good, however once I started to stretch the image there is a dark band along the top of the image attached (aggressively stretched to highlight). I also tried manual flats but the result was exactly the same. Does this look like a flats issue or something else? The equipment was as follows: ZWO ASI 294MC Pro > Spacers for required 55mm back focus > OVL Field Flattener with 2" UV/IR cut filter > Evostar 72ED Thanks, Stu

Looks great mate 👍

I wouldn't bother with the duo band filter either as like others have said I don't like the look they give on this target and they kill the more reflective parts of the nebula. I haven't really imaged M42 in anger this year but I did manage to get this unfiltered, from a bortle 8 zone 18x150 second subs (45 minutes) wth a stock dslr. I processed the stack twice, once for the core and once for the rest of it and then blended the two together

Good going, my old standard HEQ5 Pro typically sits around 0.3 total RMS error too 👍

Outstanding

I've also been looking for a tutorial on how to do this exclusively in photoshop but as you mentioned everything seems to be geared toward PixInsight and APP and the couple of tutorials out there aren't that great. If you have figured out how to do it I'd love to know

Lol isn't that the truth. Nice image non the less 😄

Looks lovely to me, great work

Great M42 👍

131 Hours 😲, I don't think I've managed a combined 131 hours on every target I've imaged over the last year. It has definitely paid off though, great image 👍

That's a great result considering the conditions. I'll be moving to an L-extreme when I eventually get my OSC camera later in the year (from dslr and L-enhance) so it's good to see what it can do FWIW I'm convinced that M42 isn't the best of targets for these dual band filters as they seem to kill a lot of the detail, especially the more reflective parts of it.

Awesome

Great work