Starwiz Posted November 10, 2019 Share Posted November 10, 2019 The Bubble Nebula. Imaged in narrowband from Mellieha, Malta. This is the first time I've used a processing technique to correct poor star shapes caused by coma. John 17 Link to comment Share on other sites More sharing options...
alan potts Posted November 10, 2019 Share Posted November 10, 2019 That's come out very nice, feel I may invest in one of the duel filters for OSC to help improve my NB content on my captures. Be a few day before I can use the scope after I have just had an operation, still getting better every day. Alan 1 Link to comment Share on other sites More sharing options...
Starwiz Posted November 10, 2019 Author Share Posted November 10, 2019 59 minutes ago, alan potts said: That's come out very nice, feel I may invest in one of the duel filters for OSC to help improve my NB content on my captures. Be a few day before I can use the scope after I have just had an operation, still getting better every day. Alan Thanks Alan, and best wishes for your recovery. John 1 Link to comment Share on other sites More sharing options...
tooth_dr Posted November 10, 2019 Share Posted November 10, 2019 That’s pretty special John. Any more capture details? 1 Link to comment Share on other sites More sharing options...
Starwiz Posted November 10, 2019 Author Share Posted November 10, 2019 43 minutes ago, tooth_dr said: That’s pretty special John. Any more capture details? Thanks. SW200p on NEQ6. ASI1600mm Pro cooled to -10C. Orion Mini Guide Scope with ASI120mc. Ha = 90s x 32 (Bin 1x1), 180s x 61 (Bin 1x1), 300s x 50 (Bin 1x1). OIII = 90s x 32 (Bin2x2), 200s x 21 (Bin 2x2), 300s x 21 (Bin 1x1). SII = 90s x 31 (Bin 2x2), 300s x 21 (Bin 1x1), 600s x 11 (Bin 1x1). RGB = 20s x 20 (Bin 1x1) each filter. Imaged over several nights. I'm still experimenting with the exposure lengths, hence so many different times. Stacked in DSS, processed in PS. Darks, Flats and Dark Flats applied. John 1 Link to comment Share on other sites More sharing options...
alacant Posted November 10, 2019 Share Posted November 10, 2019 (edited) On 10/11/2019 at 08:10, Starwiz said: processing technique to correct poor star shapes Hi. Lovely image. I don't understand the colours, but I'm trying. I think however your idea for star processing is great; we're no longer limited by old algorithms. Software seems the way to go. I'd be delighted to see the end of our coma correctors. Forever! Cheers Edited November 12, 2019 by alacant 1 Link to comment Share on other sites More sharing options...
carastro Posted November 10, 2019 Share Posted November 10, 2019 Very nice image. Quote I've used a processing technique to correct poor star shapes caused by coma. Can you share this technique with us? Carole Link to comment Share on other sites More sharing options...
Starwiz Posted November 10, 2019 Author Share Posted November 10, 2019 29 minutes ago, alacant said: Hi. Lovely image. I don't understand the colours, but I'm trying. I think however your idea for star processing is great; we're no longer limited by being forced to use old algorithms. Software seems the way to go. I'd be delighted to see the end of our coma correctors. Forever! Cheers Thanks. I used this technique for shaping the stars: 1 Link to comment Share on other sites More sharing options...
Starwiz Posted November 10, 2019 Author Share Posted November 10, 2019 (edited) 7 minutes ago, carastro said: Very nice image. Can you share this technique with us? Carole Thanks Carole. Technique as posted above. I used Stratton to remove the stars from the nebula, so I could process them separately as RGB, then used Stratton again to create a stars only image which I then used the technique on. The stars only image, I used levels to saturate the black point, so there was no background other than the stars. I added this to the nebula as a stars layer, setting its mode to 'lighten'. John Edited November 10, 2019 by Starwiz 2 Link to comment Share on other sites More sharing options...
DaveS Posted November 10, 2019 Share Posted November 10, 2019 How do you manage to get Stratton to do anything meaningful? When I've been trying it I get horrible halos where stars were, and trying to get stars only in Stratton is even worse. Link to comment Share on other sites More sharing options...
Starwiz Posted November 11, 2019 Author Share Posted November 11, 2019 9 hours ago, DaveS said: How do you manage to get Stratton to do anything meaningful? When I've been trying it I get horrible halos where stars were, and trying to get stars only in Stratton is even worse. I'm processing each Ha, OIII, SII separately in Straton. Then for the stars, I'll also process each channel of RGB separately. I too, get unwanted artifacts especially where the brighter stars were. I use the PS spot healing tool or brush to clean these up. For 'stars only', I use the Straton tool 'Subtract main image from reference image'. In this case, it doesn't matter if there are some unwanted artifacts left over, because I'm going to use levels to saturate the black point, ready for when I reintroduce the stars as a separate layer. However, if there are any that get through this process, such as brighter parts of a nebula, then I'll just clean these up with the spot healing tool or brush. John 1 Link to comment Share on other sites More sharing options...
DaveS Posted November 11, 2019 Share Posted November 11, 2019 Thanks John, looks like I'll need a PS equivalent. But the proof of the pudding, as they say, and your image is very good. 1 Link to comment Share on other sites More sharing options...
MarsG76 Posted November 11, 2019 Share Posted November 11, 2019 Very nice image.. personally I'd try to decrease such a heavy green hue.... but great image nonetheless. 1 Link to comment Share on other sites More sharing options...
Starwiz Posted November 11, 2019 Author Share Posted November 11, 2019 2 hours ago, DaveS said: Thanks John, looks like I'll need a PS equivalent. Gimp has the Healing Tool which should do the job for you. John Link to comment Share on other sites More sharing options...
Starwiz Posted November 11, 2019 Author Share Posted November 11, 2019 1 hour ago, MarsG76 said: Very nice image.. personally I'd try to decrease such a heavy green hue.... but great image nonetheless. Thanks. Yes, I was a bit undecided about that. When I tried decreasing the green, I started to lose detail in the Ha component, so I left it as it was. I also have two laptops and it looks different on each and different again on my phone. One day I'll work out how to calibrate the displays. John Link to comment Share on other sites More sharing options...
MarsG76 Posted November 11, 2019 Share Posted November 11, 2019 26 minutes ago, Starwiz said: Thanks. Yes, I was a bit undecided about that. When I tried decreasing the green, I started to lose detail in the Ha component, so I left it as it was. I also have two laptops and it looks different on each and different again on my phone. One day I'll work out how to calibrate the displays. John Monitor display differences are a big factor when color balancing photos.. astro or otherwise.... to preserve the detail, try desaturating the image and use the gray scale as a Luma channel.. the color can be used as a color channel, (even gaussian blurred slightly), and you can easily adjust the hue without losing any detail, which will be preserved by the luma gray channel. 1 Link to comment Share on other sites More sharing options...
Starwiz Posted November 11, 2019 Author Share Posted November 11, 2019 51 minutes ago, MarsG76 said: Monitor display differences are a big factor when color balancing photos.. astro or otherwise.... to preserve the detail, try desaturating the image and use the gray scale as a Luma channel.. the color can be used as a color channel, (even gaussian blurred slightly), and you can easily adjust the hue without losing any detail, which will be preserved by the luma gray channel. Thanks. 1 Link to comment Share on other sites More sharing options...
DaveS Posted November 12, 2019 Share Posted November 12, 2019 23 hours ago, Starwiz said: Gimp has the Healing Tool which should do the job for you. John I freed up some space on my boot drive and downloaded the latest version. Looks to do the job. 1 Link to comment Share on other sites More sharing options...
Starwiz Posted November 12, 2019 Author Share Posted November 12, 2019 6 hours ago, DaveS said: I freed up some space on my boot drive and downloaded the latest version. Looks to do the job. Good stuff! Link to comment Share on other sites More sharing options...
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