Sleepless in Yosemite—Yosemite in Spring 2014 Trip Report

By Jeff Vanuga on Jun 04, 2014

California is world renowned for its ideal climate—and, coming from Wyoming where it snowed six inches on the day I left for Yosemite National Park, I have to admit it was a nice contrast at first. But maybe the warm, dry weather turned out to be too much of a good thing! When I think of landscapes in Yosemite I envision rising clouds and shafts of light as seen from Tunnel View and other iconic photographic locations in the park. We encountered cloudless bluebird skies and experienced drought conditions that were evident by the low water levels in ponds and a general lack of desirable flower blooms. So, with a high pressure system sitting over California for the week, it was time to implement Plan B.

One of the pleasures of leading photography groups is the flexibility of the participants. Since we were in the park during a full moon, and given the current weather conditions, I offered the group the option of night photography. The plan was to photograph Upper and Lower Yosemite Falls, and to shoot El Capitan. No one in the group had done any night photography prior to this trip and they voted to give it a try. My one condition was that everyone had to agree to the night shoot and to forego a sunrise shoot the following day if we stayed out to photograph through the night.

The highlight was that we were in the park during a rare lunar moonbow known to appear at Yosemite Falls at night. A true moonbow is lit by the light of the moon—not from the sun—and occurs in three to four-day stretches up to four times a year, mostly in the springtime. John Muir was aware of this rare and colorful event and named them “Lunar Spraybows.” Researchers from Texas State University have studied the phenomenon in depth and concluded there are several factors that create moonbows: clear skies, dark skies, adequate mist, bright moonlight, and perfect alignment.

What started as a one-night project turned into three! We had an absolute blast photographing though the night, and enjoying the serenity of the park when the crowds had disappeared and quiet returned to Yosemite Valley. Our exposures during the moonlight photography shoots were approximately 25 seconds at f/4.5@ISO1600 and required a bulb setting along with a cable release and a sturdy tripod. Focusing is another issue and there are two approaches to this technique. One option is to set up during daylight hours when one can pre-focus to be ready for night photography. The other technique—the one we used—is to focus by process of elimination. In this case, one does not set the focus on infinity and expect sharp results. It turns out to be a tedious process of focusing near the infinity mark, viewing the image on the LCD and keeping your fingers crossed that the camera is in focus. This process can take up to a half hour just for the initial set-up. Those with some of the newer LCD screens, like on the Canon Mark III, have the added benefit of the Live View function, which works great for focusing under dim or even dark conditions. Lastly, I encouraged participants to turn off their image stabilization along with the autofocus—which greatly improves the odds of getting sharp images during longer exposures.

We shot star trails. One of the issues with star trails is that in order to get long star trails you need longer exposures of 20 to 30 minutes. Digital cameras have two disadvantages. One is digital noise from the long exposures and the other is the fact that a sensor could burn out individual pixels if it gets too hot—damaging the camera. Since I did not wish to take this risk or have digital noise, I opted for short exposures of less than 30 seconds. Each 30 seconds of exposure equates to approximately .5 degrees of star arc. So, in order to get some nice arcs, one needs to take 20 to 40 images and combine them in either Photoshop or star stacking programs. During the middle of the day, I reviewed several techniques with the group, including layering each image in Photoshop® and combining them with blending modes or via a free new software program I came across over the Internet called StarStaX®. StarStaX® works for PC or Mac and is very easy to use, but you need to use JPEG or TIFF file formats in order for it to work. It will not work directly from your RAW files. For my purposes, stacking the images in Photoshop and using the blending mode is easier and works directly with the RAW file.

During the afternoons we shot other iconic locations within the park. We were treated to open roads up to Glacier View and Tioga Pass—which are usually closed this time of year due to snow. But because of the drought they were open unusually early. Along the Merced River with Half Dome reflections, our group had a couple of nice shooting sessions where it was handy to have split ND filters and polarizers on hand. While we may have missed a few sunrises during the week, we were rewarded with some outstanding images of the night sky around Yosemite Valley. Overall, it was a great shoot and I had the pleasure of some great company—all par for a Van Os Photo Safari!