My first comet image in 28 Years...

[BruceG]

Hi all, The last time I photographed a comet was Halley in 1986. Then t was an old Pentax with 400 ISO Ilford B&W film push processed to 3200 ISO. Today I feel like a child playing in a sandbox. My pix is 35x50 seconds and when stacked on stars, the comet was obliterated to a weird elongated fuzzy mess. When stacked by the comet itself I get the star trails. I see shots over on the solar system section where peeps are stacking on both stars and comet. How is this done? I don't see any option like that in Nebulosity 3 (the program I use for stacking). Is this only available in DSS or is there a workflow to use in order to get a tidy star field and a nice comet? Any guidance appreciated.
Cheers,
Bruce.

[nebulosity.]

Nice image there Bruce, I'm in the same boat. I got an hour of subs of Lovejoy with the newt and had a real head ache stacking in Nebulosity as well. I tried using some meadian clip thingo as others have suggested bit it didn't work real well at all.

Can't use DSS ect because I got a Mac, will be keen to hear what the experts do.

Jo

[Andy01]

This .pdf originally posted by Cometcatcher (Kevin) explains the technique - I made this image using this technique back in August - and I use a mac :)
http://www.astrophoton.com/tips/comet_images.pdf

Hope it helps. :thumbsup:

Cheers

Andy

[pluto]

That's really nice, great work :D

[cometcatcher]

Thanks Andy. I keep losing that link.

Nice image Bruce! Nothing wrong with still comet in star trails. I think it gives it a sense of motion.

I put the question out on another forum with two pics, one with star trails and one with still stars and comet to see what they liked the best. The majority seemed to like still comet and stars. Rotters. :P Fair enough I suppose when there are pretty stars in the background. And the very best pictures from Damian Peach for instance do this also. But it can be quite a processing nightmare in a rich starfield. I found it doesn't always work to plan. There are artifacts in the dual stack to clean up and the blending can be a bit iffy. I suppose with lots of practice it gets easier.

I wanted an easier approach to shooting still comet and stars. I looked at lots of images, scope combinations and methods. I discovered the best images seem to come from those crazy fast hyperstar scopes. Comets like fat, fast scopes. I can't afford one of those so I got the next best thing - an 8" F4 Newtonain. I keep the total exposure just long enough so the the comet trails just slightly, not enough to blur tail details. I stack in DSS using a median stack which helps "round" the comet nucleus. I then stretch the life out of it, mostly with the curves option in photoshop. I have to do several passes as DSS makes the final image quite dark. DSS also sucks out the colour. I have to put it back in by increasing the vibrance / saturation.

If you're not doing so already, shoot with RAW files. They usually have greater bit depth so can be stretched further to bring out fainter details.

[BruceG]

Hey thanks Andy for the link - looks great but alas I don't have Photoshop and probably wont have for a good while yet.

Hi Kevin - strange that you mentioned a fat and fast system (which my little refractor aint), a great friend of mine has lent me a 8" f4 newt with a really cool rotator. Just don't know if my HeQ5 can take the weight and it would have to be unguided as I can't figuire how I would ride my ST80 on top of it.
But is does scream out to give it a go. Hmm whats the weather going to do tonight?