C4628 The Prawn Nebula, lies 6000 light years distant. I started this on on April26. I would have more data but the scope fogged up right down to the main mirror. It was also difficult to process as the CLS can mess with the colour balance.
This is a composition of 151 subs with a Baader Semi-Apo filter and 140 subs with an Astronomik CLS over two nights for a total of 291 x 30 seconds. 8" F4 Newtonian, Pentax K-5. Astrobin ---> http://astrob.in/180183/0/
Nice colours as usual, Kevin, and a pretty image. I don't know how you do it with those tiny subs
Thanks Rick. I don't know either but they seem to work if there's enough of them.
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Originally Posted by Tony_
Another great image Kevin - nothing wrong with 30sec subs.
Tony.
Thanks Tony.
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Originally Posted by Placidus
A lovely image. Beautiful use of colour.
Best,
Mike
Thanks Mike. The colour was tricky to do with the filters, but they do tent to "wake up" the camera's response to Ha.
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Originally Posted by Spookyer
Good work. That is a lot of files to handle.
Thanks Brett. Yes DSS chugs away for ages on so many files. I'm thinking of using a second computer for stacking if I keep up this madness.
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Originally Posted by nebulosity.
Great stuff Kevin, the fainter stars maybe look a little muted but you have done a really good job displaying the background.
Cheers
Jo
Thanks Jo. I've noticed the nebula really pops out with fewer or muted stars and am still working on the right "look". I can see why Fred likes to get rid of stars completely! Never thought I'd say that lol.
For a traditional RGB image, the colours look very good Kevin. The image looks a little too soft for my liking. Not sure if this the data in general or the application of noise control. If you are using photoshop, you could try noise inverse masks to apply noise control to dim areas while leaving the brighter areas masked i.e. no or limited noise control applied. I did a tutorial for lightbuckets ages ago on the topic. You can view it here, scroll to the right to see NIM.
Thanks Jase. I have noticed the softness and was wondering about it's origin, whether it's DSLR related or something I'm doing in the processing. I have noticed that in general CCD images are often sharper than DSLR (Bayer Matrix?) but that may just be better processing skills of the user. I will try masks when doing noise control next time to see if that helps. I just remembered I had dew problems that night also and used some of the dewey data which may be a contributing factor. Time will tell. I learn from every image.
Last edited by cometcatcher; 17-05-2015 at 03:11 PM.
Could well be Kevin. Moisture will give that soft dreamy look. Perhaps your next step up is a OSC CCD?? Looks like you've got the basics under control to move to the next level.
I've been thinking about it a lot and I think it's probably just over processed for the amount of data I have. Because my DSLR is not modified, I really should be using double figure hours to get enough Ha data. I think the processing short cuts I use to stretch micro data contribute to it being soft.
The problem is I really like my K-5. It's a self contained OSC camera that doesn't need tethering to anything. I enjoy my KISS astrophotography. And it's perfect for comets. A CCD, while no doubt getting better pics would introduce a complication that I'm not sure I'd enjoy without a full blown observatory.
An astro modified K-5 or similar may be the best step up at this point in time, at least when shooting Ha nebula.
