tag:blogger.com,1999:blog-6953966401086641771.post4016552497151293710..comments2024-03-29T11:18:01.139+02:00Comments on Astro Anarchy: Star removal techniqueJ-P Metsavainiohttp://www.blogger.com/profile/17779793358827771439noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-6953966401086641771.post-1461287197306616382008-11-12T10:08:00.000+02:002008-11-12T10:08:00.000+02:00Hi again,You have a very good astro lens!Fast opti...Hi again,<BR/><BR/>You have a very good astro lens!<BR/>Fast optics collects LP fast as<BR/>well. I think, you can go 10-20<BR/>min. with H-a.<BR/>An other great filter to shoot emission areas is a UHC-filter.<BR/>I have a Baader UHC-s.<BR/>It cuts much more, than the filter<BR/>you are using now, IDAS-LP is good<BR/>for broadband targets, like galaxies, though.J-P Metsavainiohttps://www.blogger.com/profile/17779793358827771439noreply@blogger.comtag:blogger.com,1999:blog-6953966401086641771.post-3044243830673286312008-11-12T09:00:00.000+02:002008-11-12T09:00:00.000+02:00Ok, it is encouraging that you can take images thi...Ok, it is encouraging that you can take images this excellent from a VMag 3 site. <BR/><BR/>Without filters I can shoot ca 1,5 min sub-images (that is when the histogram on the back of the camera is reaches ca 40% to being over exposure). I have not checked what I can achieve with filters even thou I did an H-alpha image of the Cygnus area (I think I used 3 min subs).<BR/><BR/>Anyway – thank you for taking your time. I will pop into your blogg every now and then to look for the star removal technique description and to look at the nice pictures of course.<BR/><BR/>BR<BR/>MattsUnknownhttps://www.blogger.com/profile/06657929661107421347noreply@blogger.comtag:blogger.com,1999:blog-6953966401086641771.post-85808335089717204302008-11-12T08:41:00.000+02:002008-11-12T08:41:00.000+02:00Hi,All my images in the Bloghas been shot from hea...Hi,<BR/><BR/>All my images in the Blog<BR/>has been shot from heavily<BR/>Light polluted Center of<BR/>city of 130.000 inhabitants.<BR/>I think Vmag is about 3...<BR/>I do mainly NB imaging for<BR/>the reason.<BR/><BR/>Br.<BR/>J-PJ-P Metsavainiohttps://www.blogger.com/profile/17779793358827771439noreply@blogger.comtag:blogger.com,1999:blog-6953966401086641771.post-38695726011858603022008-11-12T00:13:00.000+02:002008-11-12T00:13:00.000+02:00Hello again J-P,I did now about dust and scratches...Hello again J-P,<BR/><BR/>I did now about dust and scratches, however using it iterative was new to me. <BR/><BR/>However it does not help me with a viel image I have. It might be a hopeless case, or I need some special techniques.<BR/><BR/>You can find it here<BR/>http://www.istarion.net/Picturepages/Vielrgb.htm<BR/><BR/>There are four more images processed slightly different on the bottom of the page. I managed to reduce the small stars in the top picture by masking of the nebula and using nois ninja on the small stars outside of the nebula. <BR/><BR/>It is however a bit risky since I might use noise ninja on faint parts of the nebula that I did not mask off.<BR/><BR/>Maybee I should use your dust&scratch iteration technique between each curve stretch in order to "deal" with the stars as they appear. <BR/><BR/>The problem seem to be that the fainter part of the nebula and the faint stars have about the same signal.<BR/><BR/>Also note that I (living in Stockholm) do not have the nice dark skies, I assume you have, so I have to take shorter exposures.<BR/><BR/>What kind of Vmag do you have?<BR/><BR/>BR<BR/>MattsUnknownhttps://www.blogger.com/profile/06657929661107421347noreply@blogger.comtag:blogger.com,1999:blog-6953966401086641771.post-18777130435106681492008-11-11T19:03:00.000+02:002008-11-11T19:03:00.000+02:00Hi Matts,I haven't had timeto write tutorial a...Hi Matts,<BR/><BR/>I haven't had time<BR/>to write tutorial about that, sorry.<BR/><BR/>Fast way to remove stars is by using "dust & scartches" filter under PhotoShop.<BR/>Start with radius ~8 and set threshold to the value where<BR/>some fragments of stars is still visible and no details in image destroyed.<BR/>Repeat this with lower values,<BR/>untill no stars are left and all the details are still in the image.<BR/>You might need four to six iterations. <BR/><BR/>Then add the image with stars top of the starless one as a layer.<BR/>Set mode to "Darken" so all dark details are restored, flatten and<BR/>enjoy. <BR/>There is a even more accurate way, but it's complex<BR/>to explane.<BR/><BR/>J-PJ-P Metsavainiohttps://www.blogger.com/profile/17779793358827771439noreply@blogger.comtag:blogger.com,1999:blog-6953966401086641771.post-74396622167431349762008-11-11T18:26:00.000+02:002008-11-11T18:26:00.000+02:00Terve J-P Metsävainio,I really like your starless ...Terve J-P Metsävainio,<BR/><BR/>I really like your starless images!<BR/><BR/>I would like to experiment a little myself with it and was trying to find a description somewhere in your blogg but could not find it?<BR/><BR/>Would it be possible for you to share some of your "secrets"?<BR/><BR/>BR<BR/>MattsUnknownhttps://www.blogger.com/profile/06657929661107421347noreply@blogger.com