Astrocookie Posted April 4, 2013 Share Posted April 4, 2013 Hi I have plenty of subs from the other night of Panstarr C2011L4 :-) I can only stack around 6 of them due to the movement of the comet against the background stars! When I try to use them all I get multiple comets. I've noticed there's a comet selection tool on DSS. Does anyone know how to use this and can I use it to align my subs correctly. Many thanks Paul Link to comment Share on other sites More sharing options...
wolfman_55 Posted April 4, 2013 Share Posted April 4, 2013 (edited) Not sure about DSS, I use Nebulosity for stacking and you can chose the alignment object. For Panstarrs I used the comet's head to stack with and got star trails. Not sure if you can do that in DSS? Dave http://i982.photobucket.com/albums/ae301/wolfman_55/Daves%20Astro%20Photos/processed_zpsc955da3d.jpg Edited April 4, 2013 by wolfman_55 Link to comment Share on other sites More sharing options...
dawson Posted April 4, 2013 Share Posted April 4, 2013 I found DSS couldn't cope, though admitedly my data is pretty poor as I'm on an alt-az mount and have limited exposure times. I did this image in registax! I still need to play with it and get the colours / levels / contrast etc right. Link to comment Share on other sites More sharing options...
Astrocookie Posted April 4, 2013 Author Share Posted April 4, 2013 Nice one James. That's similar to what I have. I notice you have star trails. Does Registax allow you to choose an alignment object. Paul Link to comment Share on other sites More sharing options...
dawson Posted April 5, 2013 Share Posted April 5, 2013 It does allow you to chose an alignment object or various ones. I just did a rough and ready version to see if it would generate better results than my two headed comet DSS was creating. As i say my data is pretty poor so i'm just pleased i can make out it's a comet; i'm not after photo of the month James Link to comment Share on other sites More sharing options...
Astrocookie Posted April 5, 2013 Author Share Posted April 5, 2013 Found a tutorial for stacking comets in DSS. You can select the comet head in each frame then choose to have the alignment on comet, stars or both! Results are pretty good on the small sample of light frames I chose to experiment on. Going to try with all my exposures tonight. Paul Link to comment Share on other sites More sharing options...
dawson Posted April 6, 2013 Share Posted April 6, 2013 Paul Can you post a link to that tutorial please? James Link to comment Share on other sites More sharing options...
dawson Posted April 6, 2013 Share Posted April 6, 2013 (edited) I found this 'tutorial'. Basically I had to identify the centre of the comet on each of the light frames. Then stack. Quite easy: http://deepskystacker.free.fr/english/technical.htm#cometstacking I'm just limited by my data, my maximum exposure time was 10 seconds before it just looked awful [more awful!] This is a composite image of 16 frames, each of 10 seconds at ISO 1600, with a Canon 600D at prime focus on a 127mm Mak-Cassegrain on an alt-az mount. Best viewed in a pitch dark room This image doesn't do justice to the width of the tail. Edited April 6, 2013 by dawson Link to comment Share on other sites More sharing options...
Brantuk Posted April 6, 2013 Share Posted April 6, 2013 Can't wait to get you to a Star Party James - you're just gonna have such a good time. Great to see how quickly you're progressing with techniques and experimenting with targets. Smashing capture showing a lot of tail spread. Link to comment Share on other sites More sharing options...
dawson Posted April 6, 2013 Share Posted April 6, 2013 I'm just not into tents. I might be as camp as a row of them, but I do like a bed to sleep in at night! JD Link to comment Share on other sites More sharing options...
Brantuk Posted April 6, 2013 Share Posted April 6, 2013 Two alternatives - get up a group together and hire a cabin on site for a few days - snug as a bug in a bed. Or there's plenty of reasonable B'n'B's very near Kelling so you could leave the gear with the EMS encampment (or I'll look after it for you) and come and go as you please. Or you won't know what you're missing lol Link to comment Share on other sites More sharing options...
Astrocookie Posted April 6, 2013 Author Share Posted April 6, 2013 Sorry James Been away at the outlaws. Looks like you found the same tutorial. I particularly like the centre on comet and allow star trails option. I wish I got some more subs now to make the trails longer. Link to comment Share on other sites More sharing options...
dawson Posted April 6, 2013 Share Posted April 6, 2013 Thats nice. Lovely contrast of the comet against the black background. You've clearly got significantly better data than me. I might try and capture some new frames next week sometime. Any star trails in my images are not by design! Haha. They are mere artefact given my data, equipment and processing technique. I'd have thought to get significant star trails you'd need subs from more than one night as the comet doesn't move that much quicker than sidereal rate; but i might be wrong. Nice work though. I'll look out to see if you get more data. James Link to comment Share on other sites More sharing options...
Astrocookie Posted April 6, 2013 Author Share Posted April 6, 2013 Hi James This shows what happened when I stacked two sets of data with a 30 min 'interlude' when I went to gather some feeling back in my fingers and toes after being camped out on the garage roof for several hours !!! I was surprised by the movement against the background stars. (Let me know if the image link worked ;-$ ) Paul Link to comment Share on other sites More sharing options...
dawson Posted April 7, 2013 Share Posted April 7, 2013 I'm only on my iphone, bit the image wouldn't open, bit i saved it to phone then looked at it in detail there. Blimey. I'm surprised there is that much movement in 30 minutes. Someone will know how many arc minutes it is moving per day away from sidereal rate. Personally i don't see the attraction of a star trail with the comet centre stage, but i don't think i've ever seen one done well to really be able to comment. Maybe you'll have to sway me. It still looks very nice. It's good you are getting plenty of images of this once in a 100000 year event James Link to comment Share on other sites More sharing options...
Astrocookie Posted April 7, 2013 Author Share Posted April 7, 2013 I think the image looks more dynamic with star trails. I will try a stack without trails tonight. Link to comment Share on other sites More sharing options...
Perkil8r Posted April 8, 2013 Share Posted April 8, 2013 I found that with the star trails option my stars were too faint to show up properly. Comet stacking in dss is a long slow and boring process, but I think the results make it a worthwhile exercise. Link to comment Share on other sites More sharing options...
Astrocookie Posted April 8, 2013 Author Share Posted April 8, 2013 I've also tried stacking with comet and stars as focus and was pretty happy with the results.. that really did take a long while. I'm going to post my final ps'ed image on the imaging thread. All critique welcome It's early day's. Cheers Paul Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now