There are two huge photo opportunities in Yosemite that occur only at certain times during the year.
The first is the Horsetail Falls experience, which I wrote about in February. The second big photo event is rapidly approaching and that is the Yosemite Falls moonbow.
The moonbow, similar to a rainbow but lit by the light of a full moon, occurs during the peak of the spring snow runoff. The bright light of the full moon reflects off of the cascading snowmelt to create an ethereal sight.
As early as 1871 John Muir wrote that moonbows could often be found forming in the fine spray coming off Yosemite Falls -- no rain clouds required -- and he described their beauty in his 1912 book, "The Yosemite."
When adequate snowmelt, a full moon and a clear sky all come together, a remarkable photo awaits. This year due to a limited snow pack, April and May will be the best bets for a moonbow image.
In a year of normal snowfall, May and June would be the prime months. Two years ago during the amazing wet winter of 2010-2011 I led a moonbow photography workshop in July.
This year the full moon is on April 25, with the moonrise at 8:02 p.m., of course it takes a little time before the moon gets high enough in the sky to illuminate the falls. Peak moonbow times are between 8:55 p.m. and 12:15 a.m.
In May the full moon is on May 24 at 7:57 p.m. with the peak photo time between 10:30 p.m. and 12:15 a.m. Of course, the day before and after the full moon will also provide enough light to photograph the event.
If you plan to make the drive into Yosemite Valley to shoot the moonbow here are a few tips to help you.
There are several different spots to set up your camera. The first is at the edge of the meadow on south side drive just before the Yosemite Chapel. This spot has easy access and no walking required. There is plenty of parking here but arrive early, as this is a very popular spot for photographers too photograph from, and it fills up fast.
The next spot is Cook's Meadow, which is located about a half-mile walk from the chapel, over the bridge to the left.
The third location is up the paved path to the bridge at the base of the lower falls. This short walk starts near Yosemite Lodge. This spot offers the most unique view of the moonbow but is also the most crowded and the probability of getting yourself, and your camera gear, soaked from the mist is great. If you decide to shoot here wear rain gear and bring some large ziplock bags for your camera and plenty of towels and lens wipes.
As far as the actual photography, the hardest thing is trying to focus the camera at dark. If you are a distance away, try setting your camera on infinity, which is the furthest point that the lens will focus on.
Another good tip is try and arrive at the location early enough to pre-focus before it gets too dark to see.
Making a proper exposure is vital to a quality image. If you are underexposed, the noise or digital artifacts will ruin your image. Light meters don't work in such faint light, so you'll have to use manual exposure. My basic exposure with my camera set on bulb and a locking cable release, is f/4, one minute at ISO 400. This exposure will be just a bit overexposed, too bright, but you can darken it later, resulting in a less noisy image than one created directly with a night-like exposure.
Of course you will need a very sturdy tripod and your camera should be set to "mirror lock-up" to avoid camera vibration (check your camera's owners manual to achieve this).
Also don't forget a good flashlight or headlamp for hands free lighting to see your camera controls.
Check out my website, www.jaysousaphotography.com. Under galleries, click "The Rangefinder" to see some of my past moonbow images. Also, if anyone is interested in a photo workshop at either the April or May moonbow event, please email me at email@example.com.
Jay Sousa, a former Sun-Star photographer, has his own photography business in Merced, conducts private classes and teaches photography at Merced College.