When we discovered Big Talbot Island State Parkwebsite north of Jacksonville one morning toward the end of April, 2010, Nancy saw Boneyard Beach and decided we needed to come back late in the afternoon for further investigation. The elevation for most of the tree-clad island is about twenty feet. Atlantic storms over the millennia have eroded the bluff to the beach and continue to knock trees down to the beach. We returned while it was still light, worked our way down to the beach and took “Trees In Their Twilight” just a few minutes after sunset. The camera was on a tripod for the 0.8-second exposure.
Since we expected a near-full moon to rise within the hour, we stayed around and took “Oak Tree Graveyard” less than an hour later, one third of the way through nautical twilightdefinition. It was so dark we needed a flashlight to change the settings on the camera. That picture took a 65-second exposure (about 8,000 times as long as your average selfie), which gave the sensor a chance to pick up light you didn’t even know was there.
During that 65 seconds, I took our little LED flashlight (so as not to overpower the almost non-existent ambient light) and shined the light back and forth over those nearest three trees in the foreground. I recall “painting with light” like this the whole 65 seconds, but Nancy distinctly remembers stopping after fifteen seconds 😕. If you sweep slowly to cover the target in one pass, you might miss a spot. Or if you linger too long in one area, you will create a “hot” spot. I recommend sweeping faster and making as many passes as you can to take advantage of the averaging effect.
What amazed me when the image finally appeared on the back of the camera after the shutter closed, was that the orange glow was still there. We’ve since gained more experience with night photography (for example, see Nautical Twilight In The Glades, Seven-mile Bridge At Twilight, Midnight In The Pinelands). Now we know that there are enough photonsdefined bouncing around at even the darkest hour so that if you left your shutter open long enough you could make it look like a bright overcast day (there would be nothing casting a shadow). At midnight, the light level could be about 1/160th that of “Oak Tree Graveyard”, meaning you would have to increase the exposure time, aperture, and/or ISO to gain over seven f-stops to get its sky to that same level of brightness. But the horizon would be blue again by then because the orange glow only lasts an hour or two, depending on atmospheric conditions.
After getting “Oak Tree Graveyard”, we headed back up the bluff and back along the trail to the van. In an open area in the woods along the way, we saw an unbelievable firefly display as we have never seen before (or since), but were too tired to stop for pictures. Nancy has been kicking herself about that decision ever since.