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Roger Clark
07-17-2012, 10:15 PM
The galactic center of our Milky Way galaxy rising over pine trees in a Colorado forest is always a grand sight from a dark sky away from cities. I was out testing my new lens at 10,000 feet, hoping for aurora (only saw a weak diffuse auroral glow), and the rising galaxy was more interesting.

Canon 1D Mark IV, canon 24 mm f/1.4 lens at f/2, 15 seconds at ISO 1600 on a stationary tripod. This is a crop from a 6-frame mosaic, each a 15-second exposure. Note the varied star colors. The full mosaic is here:
http://www.clarkvision.com/galleries/gallery.night/web/milky.way.over.forest.c07.16.2012.C45I0481-6.g-1024v.html
which shows \ the population I (bluer stars near the top of the image) versus the older, lower metallicity redder stars around the galactic bulge.

Roger

Nick Palmieri
07-19-2012, 01:01 PM
Very nice! Could you explain why the glow is orange? Thanks. TFS

Roger Clark
07-19-2012, 01:31 PM
Very nice! Could you explain why the glow is orange? Thanks. TFS


That is dust in the galaxy. Just as a sunset gets redder with smoke/dust in our atmosphere, transmitted starlight through dust appears red. However, after posting this image and looking at the histogram more, I think the blue channel needs a little boost. I probably subtracted too much blue when I subtracted some light pollution. That would make the clouds a little more brownish.

There are 3 kinds of gas/dust clouds in the sky (ignoring the ones in our atmosphere), called nebulae: light transmitted through dust as this image shows (making reddish color), light reflected from dust, making blue color (Rayleigh scattering like we see with our blue sky), and emission nebulae (like neon signs) only dominated by Hydrogen emission (red), oxygen emission (green) and other atoms.

Roger

Richard Stern
07-19-2012, 03:34 PM
Wow.......!! That's a terrific image, and the inclusion of the silhouetted trees adds to the overall effect. Perfectly exposed.

Richard

PhilCook
07-20-2012, 02:42 AM
Breathtaking shot Roger, stunning color and the pine trees work in well...soooo good !

Morkel Erasmus
07-20-2012, 03:56 AM
nice work here Roger - I have found that shooting in a cooler WB really helps eliminate the redness and brings out the magenta and blue star colours better - I normally use fluorescent WB.

that 24mm f1.4 must be a treat for these kinds of shots...
:bg3:

Rachel Hollander
07-20-2012, 06:59 AM
Wow Roger, all I can say is well done.

TFS,
Rachel

Don Lacy
07-21-2012, 06:35 PM
Amazing image Roger

James Fuller
08-04-2012, 08:49 AM
Fantastic shot! With the large aperture setting, are you focusing on the stars or the trees? Thanks.

James Fuller
08-04-2012, 01:57 PM
Also, do you use imaging stacking, or is it a single exposure? Was in camera Long Exposure NR used?

Roger Clark
08-17-2012, 10:19 AM
Hi James,
Sorry not replying sooner--I was away in the Serengeti off the internet.

To answer your questions:
I focused on the stars. It is a single exposure, no stacking, and no long exposure NR.

Roger

Gerald_Gilligan
08-22-2012, 09:22 PM
Hi Roger,

Great image, I went back to the larger image and really liked the un-cropped version. Cropping is as subjective as other considerations but I also like the the image as presented.
The 24 mm f 1.4L is a sweet lens and this image proves that. A time lapse would have been really cool to see with your chosen foreground...

Jerry