Chasing Rainbows

  

With Thanks to Sir Isaac Newton

Summer is the season of rainbows.  They are a magical, improbable manifestations of nature, which often seem to appear without warning and disappear just as quickly.  It is no wonder that they have long been associated with mystical properties, including the fabled pot of gold at their base.  Last week I was reminded that, although they are beautiful, rainbows are actually just a simple manifestation of the prismatic effect of light bouncing through rain drops and that, given the right conditions,  their occurrence can often be predicted.

Raindrop Physics

About four years ago, I published a blog article about rainbow photography, and last week I was once again able to put to work what I learned from my own research.  I was at home when a strong summer downpour passed through my village of Spofford New Hampshire.  I was just getting ready to settle into our gazebo to for some writing, but instead I

Double Rainbow - Opposite Color Spectrum

decided to do a little rainbow chasing.  I knew that rainbows often form as lines of showers pass by.  The storm must also be followed by unobstructed sun shining through to catch the rain drops at a low enough angle to be reflected back and refracted, separating the light into its full visual spectrum.  The secret is to place the sun at your back and look into the rain clouds as they move away. 

Full Unobstructed Rainbows are Easier to Find on the Coast
Rye Beach, New Hampshire

First Find a Rainbow

On this day, I was a little late in recognizing the conditions. I had no rainbow in Spofford, but I had a reasonable idea where one might form.  I grabbed my camera bag, jumped into the car and headed west toward Keene in hopes of catching up to the receding edge of the storm.  I first reached  my rainbow on the outskirts of the city. 

Find a Foreground

Nice Color but Distractions along Route 12

The two key steps which lead to great rainbow images are first, find a rainbow.  The second is to find something interesting to put in front of the garishly colored arch.  I have seen innumerable pictures of dramatic rainbows spoiled by weak and distracting foregrounds.  Telephone poles, wires, housing projects, windshields and highway overpasses,  all may provide a sense of place, but they tend transform the magic into just an uninspiring smear of color across an ugly distracting foreground.  Once you find your rainbow your next thought should always be “where can I go to put something of interest in front of it, that is also close enough to get to before the rainbow fades”.

First Rainbow

As I moved into Keene, my choices for foregrounds  were limited.  I needed to get away from all the layers of development.  I careened  down a industrial park service road and drove beyond the buildings to be able to shoot down the dead end circle and into the trees of the an old Ash swamp.  Not a great foreground, but I got a reasonably good arching rainbow.  After capturing  the “fact” of the rainbow,  the next step was to try to get a more complete and balanced image. 

Chasing the Storm's Edge

Cemetery Gazebo

I headed out chasing the color, always angling west, to keep myself on the critical back edge of the storm with the unobstructed sun to my back.  Given the location of the rainbow and its direction of motion, I didn’t think I would get much from Keene and so I headed southwest on route 12.  A couple of times the colors seemed to be fading, but then I caught up with the storm. I had in mind a spot in Troy that I though would give me a long view, and some nice unobstructed perspectives.   My target was a cemetery just outside of the village, that sits on a knoll with a clear view to Mt Monadnock.  On this day the storm was obscuring the mountain, but  the color was still there, shining brightly against the receding dark clouds. 

Rain Drops

I first grabbed a couple of multi-image panoramas, to capture the full arc of the colors.   My first attempt was marred by multiple rain drops which caused smudges on my lens.  The problem with multi-image panoramas is that any dust or smudges repeat across each of the frames which are merged into the final image.  I cleaned the lens, but my second attempt, although clean, was not as dramatic. 

Content Aware Fill

Post Fill

 I ended up spending too much time in Photoshop using combinations of Content Aware Fill and the Healing Brush to remove all the drops, but the pain fades, and I am happy with the results.  The cemetery also has a nice Gazebo up on the hill.  I had used it in the past for a foreground and once again I was able to combine it with a vivid portion of the rainbow to construct an effective image.

Worth the Tedium

As the sun dipped into the clouds on the horizon, I was finally forced to give up the chase.  I was still able to catch some of the warm light on the Black Eyed Susan decorated cemetery wall and, later, the clear sky opened for a nice view of the craters of the moon.

Given that I left home with only the potential for a rainbow, I was happy with my results.  It just goes to prove that, with a little physics, we don’t have to depend on pure luck to capture one of nature’s most colorful shows.

Jeff Newcomer, NEPG
partridgebrookreflections.com
603-363-8338