02.05.17: Sunbeams

Sun beams around a cliff on the Old Man’s Cave Trail, Hocking Hills State Park, Logan, Ohio. 

PHOTO OF THE WEEK ARCHIVES

Technical information

Date/time:
June 17, 2006,
8:34 a.m.

Location
39°26’4” N,
82°32'23" W
(Show in Google Maps)

Camera: 
Canon EOS 20D

Lens: 
Canon EF-S 10-22 f/3.5-4.5 (11mm) 

Aperture: 
f/14

Shutter: 
1 second

ISO: 
100

Sunbeams, like the ones in this photo on the Old Man’s Cave Trail in Ohio’s Hocking Hills, add an eye-catching element to a photograph. But sunbeams (or crepuscular rays, for those scientific-minded readers) aren’t the easiest things to capture with a camera. 

I know techniques I can use to increase the likelihood of getting sunbeams in a shot: shoot shortly after sunrise or shortly before sunset; place some sort of object — clouds, trees, buildings, etc. — between the camera and the sun to diffract the light; shoot in an area with moisture or dust in the air to reflect the light. Even knowing those techniques I still find that getting a photo that includes sunbeams is as much luck as skill.

I do have a number of photos showing sunbeams in a forest. In those cases I shot through trees toward the sun. The diffraction caused by a stand of trees between the camera and the sun can, in the right conditions, create rays. Same thing with shots I have of buildings with rays (place the sun slightly behind a building) or sunrises over the ocean with rays (the sun was mostly hidden behind a cloud).

But this was a different situation. 

I was hiking the Old Man’s Cave Trail in the Hocking Hills when I saw a scene that I liked. Sunlight was highlighting the rocky creek bed and the edges of cliffs. I thought it would make an interesting shot so I set up my tripod and composed the scene in the camera’s viewfinder.

Just as I was ready to press the shutter release I noticed that the sunlight was breaking into detectable sunbeams. I guess the rising sun had reached the point where the light was being diffracted perfectly by the cliff and neighboring trees. Or maybe the moisture trapped in the hollow reached the perfect saturation to reflect the light. Or maybe both.

I don’t know what caused it. I just know I could see sunbeams and hoped that the camera could capture them. 

This was going to be a difficult photo even without trying to capture the sunbeams. The light difference between the highlights on the rocks and the shadows under the cliffs was significant. The human eye and brain can process a high-contrast scene, but a photographic exposure would turn the shadows to pure black or the highlights to burned-out white … or both.

I already had the camera set up to shoot a series of shots at different exposures (bracketing, in photo terminology) to enable me to select the shot with the best exposure (some shadow detail, some highlight detail) for use. When the sunbeams appeared I altered my thinking. I knew I needed to underexpose the scene to be able to capture the sunbeams, but exposing for the sunbeams meant that I would lose all shadow detail. The bracketed exposures would allow me to combine the separate files (and separate exposures) into a single high-dynamic range (HDR) photograph — one image that retains detail in both the blacks and whites, detail that would be lost in a standard single-exposure photograph. This would increase the chances that the sunbeams would be clearly visible in the final image without losing important detail in the shadow areas.

When I returned home and loaded the files onto the computer I quickly went to this scene, selected the bracketed images and had Photoshop combine them into one HDR image. I saw visible sunbeams. I retained shadow detail. I had my shot.

Even without sunbeams, the Hocking Hills is a great area for photography. It’s terrain is much different from the mostly flat land in other areas of Ohio. Blame it on the Wisconsin glacier that covered Ohio from 85,000 to 11,000 years ago. It flattened the area, but southeastern Ohio (about an hour’s drive from my house) was outside the glaciation of the ice age and remained ruggedly hilly and forested.

The same glacier that flattened much of Ohio is responsible for creating the Hocking Hills, one of the most geologically unique – and photogenic – areas in Ohio. The ruggedly hilly section of southeastern Ohio features gorges, cliffs, caves and waterfalls created when torrents of water from the melting glacier rushed through that area.

According to Wikipedia: “When the glacial torrents found cracks in the hard capstone, the water poured through to flush out the soft middle layer. This left long tunnels where the gorges are today. Eventually, the weight of the tops caused them to come crashing down. The ‘slump rocks’ in the gorges today are what’s left of the hard top layer. In just a few centuries, the rushing waters of the glacier carved the soft middle layer of sandstone into the myriad dimples and wrinkles that decorate the cliffs and grottos today.”

The waterfalls, deep, rocky gorges and towering, forested hills make Hocking Hills State Park one of my favorite areas for photography. It’s about an hour’s drive from my house, but it’s worth the trip.

Old Man’s Cave Trail, where I found this scene, is named for a hermit who lived in the large recess cave in the gorge around 1800. It’s a beautiful gorge that features several large waterfalls, a series of rapids and small waterfalls and the gigantic cave that gave the park its name. The cave is located on a vertical cliff about 75 feet above the stream and measures 50 feet high, 200 feet long and 75 feet deep. The trail, like others in the region, is filled with large slump rocks in and around the stream.

Each week I will post a photo from my collection with an explanation of how I got the shot. Previous photos of the week are in the archives.