Sirius Diffusion Over The Gore Range
I had an idea for a shot with constellations Orion and Canis Major (with Sirius, the brightest star in the night sky) setting over the rugged peaks of the Gore Range. So with a thin moon rising in the east, I had lot of cold weather gear and a what I hoped was a pretty good plan to make it happen up on Ute Pass.
Everything went according to my plan with clear dark skies and the constellations lining up horizontally above the peaks right as gentle light from a rising moon started to illuminate the scene. But then, some thin clouds showed up to diffuse the light from the brighter stars and reflect the light pollution visible from the Summit County ski towns a little ways to the south. This changed the look of the scene entirely and for me, it made the scene turn into something really special!
One of the things that makes this scene so compelling is that rugged Gore Range. It may not far from Denver, but the Gore Range is protected by the Eagles Nest Wilderness Area which prohibits use of any motor vehicles. This helps to explain why we see so few images taken from inside the Gore Range and the Eagles Nest Wilderness Area.
How I Got The Shot
As I'd been able to shoot at a relaxed pace as the constellations got lower in the sky, I was able to try out a variety of lenses and settings. In the end, I decided on my 105mm f/2.8 VR lens - which believe it or not, is primarily a macro & portrait lens. It sure works great here thanks to the long reach and the bright aperture.
For this sequence, I made sure to get my tripod level first before getting my scene in perfect focus and checking my exposure settings. Then, I shot from left to right with about a 40% overlap between frames. I did this without delay to minimize the apparent movement of the stars between frames.
� Camera Body -�Nikon D800 Digital SLR Camera
� Camera Lens -�Nikon AF-S VR Micro-Nikkor 105mm f/2.8G IF-ED Lens
� Tripod Head -�Acratech GV2 Ball Head / Gimbal Head with Lever Clamp
� Tripod Legs -�FEISOL Elite CT-3472 Rapid Tripod Legs
� Remote Trigger - Vello Shutterboss Version II Timer Remote Switch for Nikon with 10-Pin Connection
Exposure Settings - 5 Frame Panoramic Image
� ISO: 6400
� Aperture: f/2.8
� Shutter Speed: 25 seconds
Before stitching the frames together, I made sure to do a good job of minimizing the visible vignetting on each of the frames as I've found this effect is a lot harder to "fix" after stitching. This is where I found Lightroom's lens correction capability to be especially helpful. Then, after stitching the frames together in PTGui, I took a few more steps in Photoshop to bring it to life.
As I'd intentionally over exposed the original raw files a bit, this allowed me to bring back the overexposed areas and show some great color in the clouds. I was specifically looking to do this in a way that kept good quality in the foreground elements as well as the sky. I'll admit that I was very pleased when I started darkening my overexposed sky and saw all the color come out.
To make this darkening happen, I just used Photoshop masks with a brush and a soft edge in combination with a curves adjustment. And while I do use more complex channel masks at times, I like keeping my masking simple when I can and I find that the hand drawn masks in combination with the smart radius and/or feathering capabilities fit my needs in most cases.
February 19th, 2014
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