Caving to demand, I took my Hawaii workshop group back up to Kilauea last Thursday night. While we didn’t get stars this time (not even close), we found something that was equal parts different and cool. If the first night’s display was Heavenly, the reprise was Hellish. We finished Tuesday with a new appreciation for our small place in this magnificent Universe; Thursday we were left awestruck by the power of nature’s creative force churning beneath us.
Everyone was thrilled to have the dark, clear skies we saw Tuesday night, but given that this was the first time doing night photography for most of the group, everyone wanted another opportunity apply their new-found skill. Before departing, I reminded them of Mother Nature’s fickle inclinations, and warned them that repeating Tuesday’s clear skies was far from a sure thing. However, I told them, clouds can be pretty cool too. They were dubious, and somewhat disappointed upon arrival—until the first images popped up on their LCDs.
Believe it or not, these images from our two volcano nights are pretty much what we all saw on our camera LCDs (very little processing necessary). They’re a good reminder of our camera’s ability to show aspects of the natural world that are missed in the human experience. A frequent photographer’s lament is the camera’s limited dynamic range (the range of tones between the darkest shadows and brightest highlights), but one advantage a camera does have over human vision is its ability to accumulate light over time. On Tuesday night, our sensors pulled from the darkness stars that were invisible to the naked eye (and also nicely brightened the Milky Way); on Thursday night, a long exposure revealed unseen cloud detail illuminated by Halemaʻumaʻu’s orange glow. Also, on Tuesday night so much of Kilauea’s glow escaped into space that the caldera floor (beyond the inner crater) remained nearly black despite a lengthy, high ISO, large aperture exposure. But on Thursday night the clouds reflected the volcano’s light back to Earth, bathing the caldera floor in an orange glow that our cameras captured beautifully.
Our cameras also allowed us to infer one more difference between the two nights: The crater glowed significantly brighter on Thursday night. I learned from a rim-side chat with a naturalist on Tuesday that Halemaʻumaʻu’s luminosity varies with the composition of its output—the higher the ratio of sulfur gas to water vapor, the brighter it glows. While this difference is sometimes difficult to detect with the naked eye from one night to the next, it became obvious when I realized that in Tuesday’s images the highlights in the crater’s burning core were recoverable in Lightroom, while the same bright region in Thursday’s images was hopelessly blown at the same exposure. Fortunately, on Thursday night I opted for a shorter shutter speed to better “freeze” Halemaʻumaʻu’s gas plume—this left the caldera a little dark (but still brighter than Tuesday), but really reveals the plume’s character.