ckp82 Posted August 10 Share Posted August 10 Following on from my previous post m51 & pacman nebula I decided to have a go at m81 and m82. I cleaned all the glass parts along the optical train. Unfortunately, there is a few dark spots remaining. In my next session I will have to try adding flats. I also added the filter adaptor that was reccomended in my previous post. I think it works better, your thoughts are welcome. Anyway the following image is 50 x 30 secs. Any feedback would be much appreciated. 6 Link to comment Share on other sites More sharing options...
PeterC65 Posted August 10 Share Posted August 10 That looks much better. I can't see any of the star distortion that you had last time. It can be hard to find the dust that causes the dark spots. It could be really tiny particles of dust that are hard to see, and they can be anywhere in the optical train from the scope objective to the camera window. Taking flats will remove these though. The background sky is still a little bright I think. That could be to do with your choice of histogram stretching or it may be from light pollution. Given the time of year, I doubt it is down to dew (which can have a similar effect). M81 and M82 are great EAA targets. I like to observe multiple objects like this together in the same frame, but M82 is a great object on its own as there is so much detail to try to tease out. 1 1 Link to comment Share on other sites More sharing options...
TiffsAndAstro Posted August 10 Share Posted August 10 (edited) 1 hour ago, ckp82 said: Following on from my previous post m51 & pacman nebula I decided to have a go at m81 and m82. I cleaned all the glass parts along the optical train. Unfortunately, there is a few dark spots remaining. In my next session I will have to try adding flats. I also added the filter adaptor that was reccomended in my previous post. I think it works better, your thoughts are welcome. Anyway the following image is 50 x 30 secs. Any feedback would be much appreciated. i imaged same thing few months ago before i got my new camera. im just stacking a version with and without flats so you will get rough idea what to expect. will post them asap. both are 4200 seconds so vaguely similar to your time on target. no flats just auto stretch in siril and a screen grab now with flats. still same as above auto stretch and a screen grab. no processing at all. i didn't like my results after i processed but now im going to have to go back and have another go at processing it more nicely Edited August 10 by TiffsAndAstro 2 1 Link to comment Share on other sites More sharing options...
PeterC65 Posted August 10 Share Posted August 10 @TiffsAndAstro Did you just process the second image with flats and no darks? I'm wondering whether I can just take flats and use the background subtraction and hot pixel removal features of SharpCap instead of taking darks. 1 Link to comment Share on other sites More sharing options...
TiffsAndAstro Posted August 10 Share Posted August 10 (edited) 7 minutes ago, PeterC65 said: @TiffsAndAstro Did you just process the second image with flats and no darks? I'm wondering whether I can just take flats and use the background subtraction and hot pixel removal features of SharpCap instead of taking darks. second image used flats darks and bias calibration frames. i would say if you're going to take some flats, take some darks too. while its ideal to match temperatures for lights, darks and bias (and maybe flats, im not certain) all you'll waste in trying it out and seeing, is a bit of time i would say your 25minutes look better than my 45 ish minutes. Edited August 10 by TiffsAndAstro 1 Link to comment Share on other sites More sharing options...
ckp82 Posted August 10 Author Share Posted August 10 @PeterC65 thanks for the recommendation. I used a lens cleaning kit which included an air blower, lens spray, lint free cloth ands a fine brush. I cleaned nearly all parts except behind the camera glass. I even took out the telescope glass to get behind them. I will definitely takes flats next time. I think the light is coming from a streetlight outside the front of my house. M82 stood out to me, even though I put m81 as the central focal point. I'd like to try easing out even more details once I get the basics down first. 2 Link to comment Share on other sites More sharing options...
ckp82 Posted August 10 Author Share Posted August 10 @TiffsAndAstro Wow the difference is amazing. Have you captured 2 extra galaxies in your photo? 1 Link to comment Share on other sites More sharing options...
TiffsAndAstro Posted August 10 Share Posted August 10 11 minutes ago, ckp82 said: @PeterC65 thanks for the recommendation. I used a lens cleaning kit which included an air blower, lens spray, lint free cloth ands a fine brush. I cleaned nearly all parts except behind the camera glass. I even took out the telescope glass to get behind them. I will definitely takes flats next time. I think the light is coming from a streetlight outside the front of my house. M82 stood out to me, even though I put m81 as the central focal point. I'd like to try easing out even more details once I get the basics down first. thing is thought, flats don't just remove dust they also remove vignetting - you can see the curved darkened corners in my first image and the lack of it in my second image. pretty much due to using flats. 1 Link to comment Share on other sites More sharing options...
TiffsAndAstro Posted August 10 Share Posted August 10 3 minutes ago, ckp82 said: @TiffsAndAstro Wow the difference is amazing. Have you captured 2 extra galaxies in your photo? yes but there's not much detail in them im extremely lazy and i wouldn't do calibration frames unless i thought it was well worth the effort. i think you'd have gotten them too if your fov was just a little wider. i re did this image again containing two session and had to crop in a lot due to light pollution (i assume) gradients. didn't want to crop those little guys out. this image below is my bestest attempt (with only free software) and a total of 13320 seconds. i can see at least two other tiny galaxies, there's probably more. there's a lot of tiny galaxies about, it seems 2 Link to comment Share on other sites More sharing options...
TiffsAndAstro Posted August 10 Share Posted August 10 21 minutes ago, ckp82 said: @PeterC65 thanks for the recommendation. I used a lens cleaning kit which included an air blower, lens spray, lint free cloth ands a fine brush. I cleaned nearly all parts except behind the camera glass. I even took out the telescope glass to get behind them. I will definitely takes flats next time. I think the light is coming from a streetlight outside the front of my house. M82 stood out to me, even though I put m81 as the central focal point. I'd like to try easing out even more details once I get the basics down first. i tried cleaning my uv/ir cut filter. i won't be trying it again as i can see a finger print on it Link to comment Share on other sites More sharing options...
ckp82 Posted August 10 Author Share Posted August 10 25 minutes ago, TiffsAndAstro said: yes but there's not much detail in them im extremely lazy and i wouldn't do calibration frames unless i thought it was well worth the effort. i think you'd have gotten them too if your fov was just a little wider. What set up did you use? 1 Link to comment Share on other sites More sharing options...
ckp82 Posted August 10 Author Share Posted August 10 28 minutes ago, TiffsAndAstro said: this image below is my bestest attempt (with only free software) and a total of 13320 seconds. i can see at least two other tiny galaxies, there's probably more. there's a lot of tiny galaxies about, it seems How did you process this image? Maybe with all these clouds I might have to start playing with the images I'm taking, here comes the slippery slope everyone talks about 😆 2 Link to comment Share on other sites More sharing options...
ckp82 Posted August 10 Author Share Posted August 10 27 minutes ago, TiffsAndAstro said: i tried cleaning my uv/ir cut filter. i won't be trying it again as i can see a finger print on it I was extremely nervous, hence why I dint take out the glass in front of the camera! 1 Link to comment Share on other sites More sharing options...
TiffsAndAstro Posted August 10 Share Posted August 10 35 minutes ago, ckp82 said: How did you process this image? Maybe with all these clouds I might have to start playing with the images I'm taking, here comes the slippery slope everyone talks about 😆 Siril graxpert and astro sharp.oh and gimp. Maybe watch some basic siril tutorials from nebula photos or deep space astro on youtube. Most important is starnet++ integration with siril. It separates stars from the rest so you can stretch and process them separately before recombining them. 1 Link to comment Share on other sites More sharing options...
TiffsAndAstro Posted August 10 Share Posted August 10 (edited) 44 minutes ago, ckp82 said: What set up did you use? I have a sw 72ed and flattener, sw SA GTi mount and a 600d, ( recently upgraded to an svbony605cc imx533 square sensor) All plugged into Nina for controling it. Edited August 10 by TiffsAndAstro 1 Link to comment Share on other sites More sharing options...
TiffsAndAstro Posted August 10 Share Posted August 10 1 hour ago, ckp82 said: @TiffsAndAstro Wow the difference is amazing. Have you captured 2 extra galaxies in your photo? I almost fell off my chair first time I used flats, the difference was so good. 1 Link to comment Share on other sites More sharing options...
ckp82 Posted August 11 Author Share Posted August 11 22 hours ago, TiffsAndAstro said: i imaged same thing few months ago before i got my new camera. im just stacking a version with and without flats so you will get rough idea what to expect. will post them asap. both are 4200 seconds so vaguely similar to your time on target. no flats just auto stretch in siril and a screen grab now with flats. still same as above auto stretch and a screen grab. no processing at all. i didn't like my results after i processed but now im going to have to go back and have another go at processing it more nicely Last night I revisited m51. I tested out the flats, dark and bias. I think I did 10x3 secs flats, 5x30 secs darks and 20x1 sec bias. I used the t-shirt and light panel technique. It's also 28x30 secs lights. I like how it's removed the spots but the stray light from off the road will always pose a problem I think. 2 Link to comment Share on other sites More sharing options...
TiffsAndAstro Posted August 11 Share Posted August 11 3 minutes ago, ckp82 said: Last night I revisited m51. I tested out the flats, dark and bias. I think I did 10x3 secs flats, 5x30 secs darks and 20x1 sec bias. I used the t-shirt and light panel technique. It's also 28x30 secs lights. I like how it's removed the spots but the stray light from off the road will always pose a problem I think. Download graxpert it has a gradient removal feature can work pretty well Also siril has a gradient remover. 1 Link to comment Share on other sites More sharing options...
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