Thursday, October 3, 2013

Tracking the Stars with Rick Parchen

"Mt. Shuksan Reflection" ~ © Rick Parchen
Click (twice) to see to the quality of Rick's low-noise image, via tracking.
Rick Parchen is one of several astro-landscape photographers who are using star trackers or equatorial tracking mounts to improve the quality of their night sky exposures. Tracking allows one to use longer exposures without producing star trails. Instead of using ultra high ISOs and large apertures to reduce their exposure time, photographers can use a tracker to lengthen the exposure time and use smaller apertures. With a tracker, a photographer is able to align his camera to Polaris, the North Star; and a built in servo motor keeps the camera tracking the stars at the same speed the earth rotates.

The old way: Astro-photographers have been using equatorial mounts for decades to photograph the stars through their telescopes, but early astro-landscape photographers who included a landscape feature in the foreground didn't use these mounts because tracking the stars cause the landscape to blur! The standard solution has been to keep exposures at 30 seconds or less, following the "600 Rule" —requiring very high ISO settings that produced noisy images. (Additionally, equatorial mounts for telescopes were expensive and too bulky to carry into remote areas.)

A new approach: Because of the recent popularity of nightscape photography, newer mount designs, just for cameras, have appeared that are smaller and less expensive. Using these smaller and cheaper trackers, a new breed of astro-landscape photographers are taking a tracked exposure for the sky (referred to as "wide-field astrophotography"), a second exposure for the landscape (without tracking), and then blending the two in post-processing.

SkyTracker
In "Mt. Shuksan Reflection", Rick used a SkyTracker camera mount for his sky exposure, then turned it off for the ground exposure. The photo is actually a 3-image composite panorama (three for the sky and three for the ground). Each sky exposure was 3 minutes @ f/4, ISO 800, using a Samyang 14mm f/2.8 lens on a Canon 6D, mounted to a SkyTracker. Each ground exposure was 3 minutes @ f/5.6, ISO 400, with the SkyTracker turned off. Lighting of the ground came from a little moonlight (about to set) and supplemented in the foreground with LED's from multiple headlamps, coming from different positions. Initial processing was in Lightroom 5. Sky and ground pano exposures were stitched together in PTGUI, with final processing and the alignment of the sky and ground in Photoshop CS6.

Editor's Note: Another inexpensive and compact tracker is the Polarie Star Tracker from Vixen Optics. And, if you're handy with tools, you can build your own "barn door" tracking platform. (I believe all of these trackers are accurate enough for tracking stars with a normal to wide angle lens, without the need of a spotting scope attachment —which is only necessary if you are using a telephoto lens on your camera.) Both the SkyTracker and the Polarie come with Polar sight holes. The SkyTrack includes a Polar scope for greater alignment accuracy, whereas the Polarie's Polar Axis Scope is a $129 add-on accessory. The instruction manuals for the SkyTracker and the Polarie should help you decide which unit is best for you. The Orion Telescope people produce two inexpensive equatorial mounts that are adaptable for astro-landscape photography. Their manual tabletop model is under $70, and their motorized unit is under $180. (You may wish to throw away their low-quality tripods and attach the units to your regular camera tripod.)

Another view: "Path to Mt. Shuksan" ~ © Rick Pachen

Rick Parchen is a Seattle-based landscape photographer who has an appetite to travel to the world and share the extraordinary view with others. "I started this adventure seven years ago and only find myself more enveloped in chasing light and setting my work apart from others. I'll travel for weeks at a time, research for months, drive thousands of miles, and walk to near exhaustion all for the potential of a perfect image. But my passion goes far beyond just seeking the sights; the real pleasure comes when viewing the art in print and putting it on display for others to enjoy." More of Rick's photography can be seen on his Facebook page, and at his website.


Royce's 2014 Workshop, Lecture & Video Conference Schedule: NightScapeEvents.com
Featured Post: Shooting Stars eBook Review — How to Photograph the Stars and the Moon

3 comments:

  1. Wesley Liikane just commented on Google+ "I am using an iOptron SkyTracker. I have been happy how portable it is and the accuracy of its tracking. I have use up to 400mm on it and run 3 min+ exposures with little to no trailing. It is amazing what is out there that we can actually capture in detail with just a DSLR and a wide angle or telephoto lens."
    https://plus.google.com/103211867253396898949/posts/9BM64D5tdAT

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  2. Jared Blash also commented on Google+, "I'm using a DIY manual hinge tracker" You can see the results here: https://plus.google.com/114460609622048188439/posts/6LrnsKUERo2

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  3. Unfortunately, there's no power switch, so the batteries drain within a few weeks regardless. Worse, the battery cover is held down with four really tiny screws, so you'll need to find an eyeglass-style screwdriver to swap batteries. gps tracking

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