Gerhard Posted April 22, 2015 Share Posted April 22, 2015 Hi all,yesterday caught a good clear sky, so went out to observe.Had a lot of difficulty setting up the scope... On the first run it didn't want to complete the 3 star align, so I had to do everything again, and fortunately, afterwards it did align...Probably to do with poor PA... I had difficulty the first time aligning well with the polaris...So then I tried M1 (was low, and the photo did not turn out too well, so not posting), M64 and NGC 5033 (not processed yet).M64 came out like this without flats:and with flats:As in the last time, big problems with tracking and coma, apart from the flats problems (really have to get me a flatbox).The galaxy is not too bad, but the edges of the photo show terrible stars...Will have to try more and harder...I'm also thinking that in the end the place where I observed (close to home) is not near as good a place for dark skies, as the place from my last post (with M3, M81/82 etc), which is at an hour's drive...http://stargazerslounge.com/topic/240657-coma-problem/?p=2621703Any thoughts? Any suggestion would be helpful...Thanks! Gerhard. Link to comment Share on other sites More sharing options...
Astrosurf Posted April 22, 2015 Share Posted April 22, 2015 That's not a bad image! Yep, you're right about the coma and needing to get flats sorted.Don't bother with 3 star align. I often get a failed alignment message.I only use 2 star. 3 star is supposed to sort out cone error, which I don't really understand! None of the imagers in my astro group do 3 star alignment.What processing sw are you using??Alexxx Link to comment Share on other sites More sharing options...
Gerhard Posted April 22, 2015 Author Share Posted April 22, 2015 Ah, will try the 2 star align, next time. For processing I use ACDSee, after stacking and stretching in DSS. I am NOT fluent in PS, to make a bold understatement... :-(but ACDSee serves me well for exposure, contrast and lighting, to take away the worst of the glares, enhance the dark, and bring out more details...But if the stacking and stretching don't deliver, I'm no wizard in post, to do anything more than those things...I've never understood layers, for example... Link to comment Share on other sites More sharing options...
glowingturnip Posted April 22, 2015 Share Posted April 22, 2015 +1 for 2-star align.3 star for me seems to pick stars I've never heard of, which are usually behind trees or virtually on the horizon, and then it fails anyway. 2-star align picks much better stars and does the job just fine. Link to comment Share on other sites More sharing options...
Astrosurf Posted April 22, 2015 Share Posted April 22, 2015 Ah, will try the 2 star align, next time. For processing I use ACDSee, after stacking and stretching in DSS. I am NOT fluent in PS, to make a bold understatement... :-(but ACDSee serves me well for exposure, contrast and lighting, to take away the worst of the glares, enhance the dark, and bring out more details...But if the stacking and stretching don't deliver, I'm no wizard in post, to do anything more than those things...I've never understood layers, for example...Ask on here about basic PS processing. You'll get plenty of advice. Just ignore what you don't understand, for the time being. It'll all make more sense once you've started building on the basics. Link to comment Share on other sites More sharing options...
Gerhard Posted April 22, 2015 Author Share Posted April 22, 2015 I processed the NGC 5033 subs, and this is what I could obtain, with DSS and ACDSee:It also shows NGC 5005, and a few other smaller objects. Anyone who knows them, I'd be happy to learn their names! Again, coma, glare, and tracking... (haven't even cropped out the stacking anomalies.)enlarging it, on the original I can make out the arms of 5033... Frustrating to see the info is there in the pic, but cannot make it come out better than this... I also played around a little bit with the stretching in DSS...I'd be happy to pass the stack to anyone who wouldn't mind at having a go at trying what might be possible in other softwares, with more experienced users... Even only to know if my "space for improvement" is largely at the pre-stacking side, or at the post processing... Any help would be most appreciated!!Tomorrow night it looks like I'll have another nice night to try again.Really need to concentrate on getting the PA right...So I also really need to check if the polar scope is correctly alligned with the mount... Maybe this weekend. Just a bit scared to mess with it... I kind of hope it's not aligned well, because maybe that could explain some of the anomalies, but I also hope it's ok, because I'm not keen on touching the alignment... I think tomorrow I'll go for M66 and company again. they're nice and high, and on the other side of the moon / city glare... Link to comment Share on other sites More sharing options...
Gerhard Posted April 22, 2015 Author Share Posted April 22, 2015 Had a brainwave, tried without the flats, came up with this:except the glare, looks a lot better, imho! Link to comment Share on other sites More sharing options...
Astrosurf Posted April 23, 2015 Share Posted April 23, 2015 Try this for gradient removal in GIMP:http://stargazerslounge.com/topic/141931-subtraction-layer-gradient-removal-refinements/ Link to comment Share on other sites More sharing options...
Gerhard Posted April 23, 2015 Author Share Posted April 23, 2015 Haven't done much with layers, but I will try that. in the post it says it works for photos that are only star fields. Will it also work with mine, which has galaxies? Link to comment Share on other sites More sharing options...
Astrosurf Posted April 23, 2015 Share Posted April 23, 2015 I wish I could help but I don't use GIMP! I use gradientXTerminator in PS. Sorry! Have a go. You might need to select out the galaxies, then do the technique, but I'm only guessing. Link to comment Share on other sites More sharing options...
Gerhard Posted April 24, 2015 Author Share Posted April 24, 2015 +1 for 2-star align.3 star for me seems to pick stars I've never heard of, which are usually behind trees or virtually on the horizon, and then it fails anyway. 2-star align picks much better stars and does the job just fine.Yesterday I did the 2-star setup, and I'm not 100% sure if it was for this, but I lost an hour of imaging, because the scope was completely off.. I caught only stars, instead of the Leo triplet... Afterwards I did the 3-star, and checked if it aligned well on objects, and it did... Link to comment Share on other sites More sharing options...
Gerhard Posted April 24, 2015 Author Share Posted April 24, 2015 yesterday's result of the Leo triplet:with archive flats:without flats:I specifically did not modify the glare too much, to show how much data from the galaxies there is, and so, to show my frustration / determination about learning how to take away those gradients, without losing my objects in the process...In yout professional opinions: how much will these images improve when I'll get a dedicated flatbox?thanks again!! Link to comment Share on other sites More sharing options...
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