Nigel G

Unfortunately another couple of hours data will make the stack around 400 to 500 frames and on my pc that's about 6 hours or more stacking on DSS 237 frames took over 4 hours ☺ I'm going to try around 1.5 hours at a dark site next available weather window. Stack them as a new image and maybe add older frames for an experiment. Nige.

Nice , like it.

this is one I found showing the nebula and one of the galaxys ,

Ken, you found more emissions than I did although it highlights more noise, maybe a mask around the nebula might help ☺ this is a very faint dso, so I'm happy with what's being extracted. Ian, the blue star in the centre is the centre of the dso with a galaxy up and slightly right and another faint and fuzzy near the bottom and left of my image. Thanks for having a go at processing guys. It's a tough one ☺

After cropping and developing at about 92% and .90 gamma, I wiped using vignetting which made the image look really horrid but a re develop brings the image back nicely ready for next stage.

I have uploaded the 2h 20 min exposure image, I think all that is needed is around 70 - 100 frames of the longest exp time you can manage with the kit one has using alt-az mount. Maybe even less, more experimenting to do ☺ I will try an experiment with one of my stacks of an easier target, using half the data for one and full data for the second, tonight's entertainment. In the second image I did over expose purposely to see if I could find the nebula so the noise level is higher but I couldn't expose the first one as much as I could the second I think due to the difference in total amount of frames, not exp time. That's my thoughts ☺I'm sure someone will disagree which only opens the door for more experimenting. Cheers Nige.

https://1drv.ms/u/s!Av3mI1-jgAvwa4nrxgPLQAAWX8U I cropped this quite a bit, around 50% to work on. If anyone wants to try please do, Good luck, I hope someone can extract more, it will be interesting to see what other programs can do. Nige.

a quick question about onedrive , how do I share ? Its ok I found out

That's a good easy to understand example and my thoughts exactly , thanks Nige.

I have just installed OneDrive and am attempting to upload the fts file to share. I'm going to a dark spot next available clear night to see what difference dark skys will make to the cats eye. also want to try my luck on M1. This weekend would be perfect but the weather man he say NO. Steve, the second image is much sharper, looks like we will have plenty of time to think about this subject with the current forecast. Nige This fts file is taking a while to upload, I guess it will at 206 MB

Exposure times, now I've been told and read in books that ( example ) 120 x 30sec exposures is equal to say 6 x 10min exposures and that you need 2 hours of data for dso's. After 9 months of experimenting I have decided this is not strictly true. I believe longer exposures are much better than shorter for finding detail and light gathering but more frames is better for noise elimination . I have taken images of Andromeda with as little as 15 minutes of data up to 2 hours of data with not much difference in the final images. The longer the exposure times the more detail captured regardless of total time. My latest image, ngc 6543 , firstly I stacked about 45 minutes of 30 to 45 second exposures, second time around I stacked 2 hours 20 minutes of 30 to 45 second exposures, both with darks and bias. Both lack the emissions of the cats eye, the second image has a touch more detail but was far better to work with in StarTools due to much less noise. The cats eye is a difficult dso to capture and I'm not disappointed with the result although it lacks most of the nebula. I think my test images of ngc 7000 showed the power of the longer exp times. Our greatest barrier is the exposure time limits of the Alt-Az mount. Having said that there are plenty of dso's as we have seen in this thread where short exposures are all you need, it's the fainter objects that require the long exp. I have posted both images of ngc 6543 so they can be compared. First the 45 minute, second the 2h 20 minutes. There are 2 other dso's within the image which are more apparent in the second image also there is a wiff more emissions . The second being far easier to process with far less noise reduction needed, I think due to there being 238 frames. Although noise is present in no 2 thats because I'm trying to extract emissions. I'm sure someone else with better processing skills could get more out of it if I knew how to upload a fits image. With 2 hours of 600s I believe the nebula would be greatly improved, I might be wrong. Cheers Nige.

Thanks for the reply Ian. DSS 64 bit and trying to load 240 frames I have sorted it. My task manager said DSS is not responding. I narrowed it down to 1 corrupt frame which did load last week, I deleted it and the rest uploaded fine. Not sure how it became corrupted. Now stacking 2 hours 20 minutes of cats eye neb, hopefully will get more details. Cheers Nige.

I'm having trouble loading light frames up to DSS it stops running. It will load darks and bias and some lights but not all my lights. Has anyone experienced this problem. Is there a limit to amount of frames. I'm trying to load 220 frames. It lets me load some of them if I do it in batches but not all of them. Any ideas Nige.

I see Elvis looking up at the sky ☺

Ken and Steve. I tried processing Kens soul tif with much the same result, the colour adjustment would not bring out the emissions like I'd hoped. Adjusting the dark saturation to 3 bought out a bit but also I think was amplifying any noise in the image. Was the image white balanced , I'm wondering if I used the correct opening tab in StarTools. Nige.

It could well be after decon , to be honest I didn't note at which point they appeared, I think I was multi tasking at the time which is when it can take hours to process while doing my books or quotes, sometimes not paying full attention ☺ I will re do it during the week and see if I can reproduce the same image. Nige.

Well I new ngc6543 was quite difficult to capture, I think it needs a few more subs to gather the info needed, I got the cats eye but only a tiny fraction of its nebula. It is there but I must add a few hours to it. M33 turned out ok for 45 minutes worth, again I will add more subs when the sky's clear up. It's another one where the colours are hard to pull out. I try to get the stars as natural as possible. Normally reducing the green and blue in StarTools. Both are around 45 minutes of 30s and 45s with darks and bias. DSS and ST. 150p alt az goto canon eos 1200d. Cheers Nige.

While I was processing M31 420mm I had hundreds of very luminous green dots in the image, which I have never seen before, each one about 3 or 4 pixels in size but covering the entire image, the only way to get rid of them was with the final noise reduction in StarTools, I'm wondering if not using darks was the cause of it. The green dots looked exactly like the small specks you get when setting a star mask in ST. I have no idea where they came from though. Strange. It's a long learning curve ☺☺

Ken, I look forward to seeing your image when it's ready, glad you found the problem and corrected it. ☺ Steve, I'm quite pleased with all the M31 images, it's quite a range of options considering I spent under £80 for the lenses, the 210mm f3.6 has a lot of potential as does the 135mm. I think the x2 adapter will be fine under dark sky's and it fits all 3 lenses so there's plenty of options available. Your first image is full of detail, definitely worth gathering more data on, one I must target myself. Also that's a cool looking set up you have there last night I had a go at imaging M33, only it wasn't in view until 11pm so I spent an hour imaging ngc6543 the cats eye nebula, this looks a difficult nebula to capture but is at a high altitude so it was relatively dark up there, I only got 45 minutes on each target due to sleep needed. I'm processing them at present and will post on completion if they are worthy ☺☺ Cheers and clear sky's Nige

I have added the 420mm lens image of M31. About 1.25 hours of 45s and 60s no dark , bias, F3.6 I'm clearly loosing photons with the amount of glass I'm shooting through with the x2 adapter for the 210mm lens, but it's usable with dark sky's. Nige.

Good luck Ken, I hope your sky's stay clear. Pretty grim here at the moment, although there's supposed to be clear here for an hour or two later. Nige.

Heavy rain and high winds here tonight, last night I got 15 minutes shooting before heavy clouds rolled in. Looking better in a few days time. good luck tonight.

Ken, Excellent image, great colour, plenty of detail. Well done, ☺☺ Oh how I wish for a clear night sitting listening to the rain pooing down and the wind blowing a gale.

Impatient me managed to find a small 20 minute window of light cloud allowing a few brighter stars to become visible , as my mount and camera can be set up and aligned in a couple of minutes I thought I'd try see what I could get imaging through light cloud, considering I only got 14 minutes of subs and it was very poor seeing I'm amazed with the final image. It's the third image of these taken with a 210mm lens on my camera I also left out dark frames for this and used bias with the wrong iso setting. I could only just make out the Plough through the orange clouds, honest. Andromida galaxy in order of appearance #1 55mm lens, around 1 hour of 45s with dark and bias. #2 135mm lens, around 1 hour of 30s iso 400 and 20s iso 800 dark and bias. #3 210mm lens 14 minutes of 30s iso 800 very poor seeing bias and no dark. #4 150p posted earlier in this thread. I have 1 more to complete the set with my 420mm when I get the chance. It's interesting to see how much could be collected from such poor conditions I know this can be greatly improved but blimey. 55mm. 135mm 210mm 150p. Nige