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Sculptor Galaxy (NGC 253)

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Posts Made By: dan kowall

June 2, 2008 04:43 PM Forum: Telescope Making

how to cut laminate?

Posted By dan kowall
Marcin Klapczynski said:

I tried to cut Ebony Star laminate yesterday using a pair of sheet-metal scissors. It started cracking and crumbeling, causing small flakes of the outer layer to fall off. Is there a way to get a nice, clean cut?
[COLOR="Navy"]***Shears will work. Only one side should flake, so just have that side of the shears face the scrap side. A carbide tooth scoring tool will do the job, too. Just do a couple of passes against a straight-edge and snap it off. The tool is just a few dollars. A fine-toothed carbide blade in a table saw is the easiest and most accurate way to cut laminate strips.[/COLOR]

Also would you glue the laminate to an unstained or already stained wood? Is a contact cement good for this purpose?
Thanks
[COLOR="Navy"]***Contact cement is the glue of choice for laminates. If given the choice, unstained wood would be the best substrate.[/COLOR]

dan kowall

June 8, 2008 02:35 PM Forum: CCD Imaging and Processing/Deep Sky

Annual M13

Posted By dan kowall
Good work, Jason.
It's resolved to the core and the star colors look fine.

dan

June 17, 2008 03:48 PM Forum: CCD Imaging and Processing/Deep Sky

M57 Ha LRGB

Posted By dan kowall
That's an excellent result, Jim.
It's deftly processed.
Did you also add a small percentage of the Ha into the blue channel?
As a further challenge for this year or some future year, there is an even fainter outer layer:
http://www.stanmooreastro.com/NGC6720.html
but that takes a big chunk of imaging time. It does beg the question: Who knows how long that central star has been puffing out layers? There's a good chance there's an even fainter, older layer out there. It just might require an entire season of imaging to catch it, though.

dan


July 5, 2008 07:43 PM Forum: Astro-Physics

M57 HaLRGB final result

Posted By dan kowall
An impressive confluence of man, machines, and processing technique.
Well done, Rolando.

dan kowall

August 1, 2008 03:52 PM Forum: CCD Imaging and Processing/Deep Sky

Barnard 169

Posted By dan kowall
That's gorgeous, Tom.
You're making a specialty of the dark and the dusty in the sky.

dan

August 5, 2008 03:50 PM Forum: CCD Imaging and Processing/Deep Sky

Network Nebula NGC 6992, 6995

Posted By dan kowall
Nicely processed, Jim.

dan

August 13, 2008 04:33 PM Forum: CCD Imaging and Processing/Deep Sky

NGC 7380

Posted By dan kowall
Hi Bob,
Your focus and guiding look pretty good but somewhere along the way in the processing you've clipped the black point. Your histogram (shown below) should look more 'bell' shaped with the lower levels falling down to near zero. If you're concerned about not showing 'noise' in the fainter stuff, longer subexposures and/or more exposure time would clear that up.


dan

August 13, 2008 04:50 PM Forum: CCD Imaging and Processing/Deep Sky

VDB142 Ha

Posted By dan kowall
Jason Boyce said:
.....I had a thought to do a bicolor version of this so I shot 28x600s of OIII on this too but it doesn't seem to have a lot,I'll see if I can make something of it though....
That's a fine start, Jason, nicely processed.
There's enough OIII and SII in the Trunk to produce an extended range of colors.
For example:
http://www.ca-astronomy.com/pages/vdb142.htm
Binning the OIII and SII will save you time if that's a concern.

dan

September 20, 2008 02:17 PM Forum: CCD Imaging and Processing/Deep Sky

What is the colour of Ha anyway?

Posted By dan kowall
Greg Bradley said:
.........But a(n) Ha
filter would not be letting through any Ha beta as that is a long way from 656nm.
Assigning some blue to it would thus be twisting the data as it would really need to be
a H beta filtered image to get the correct H beta intensity........
True, but from a practical standpoint you'll find that an Hb image almost always looks like the Ha image of that area, just not as intense. Assigning 10-15% of your Ha data to blue isn't 'twisting' the data in this instance, it's more a matter of not wasting time to get the Hb data and then finding that it just looks like noisy Ha data.
Something like making a synthetic green channel is indeed manufacturing data, but you're on safe ground with the Ha and Hb mixture.

dan

October 2, 2008 04:23 PM Forum: CCD Imaging and Processing/Deep Sky

IC 5068

Posted By dan kowall
Well rendered and artfully framed, Jim.

dan

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