Turks and CaicosSunsets, Sunrises, & the Green Flash
Be aware that the sun is capable of damaging your eyes. At sunset, the sun is typically safe to look directly at, however, it still may be too bright in certain circumstances. Never look at the sun through magnified optics at any time of the day unless an appropriate solar safety filter is used.
green flash is a phenomenon that is occasionally observed for a slight moment just as the sun sets or rises.
Three effects come together to create the green flash: the refraction of light through the atmosphere, the scattering of the long wavelength blues and violets, and a mirage.
The earth’s atmosphere refracts (bends) light, and the various colours are refracted to slightly different degrees. The longer wavelengths, starting with red, are refracted less than the shorter wavelengths such as greens, blues and violets. Because of this, the red, yellow and orange visible images of the sun actually “set” an instant before the green. A minor green fringe can often be observed at most sunsets when the sun is optically enhanced, either through photos taken with a telephoto lens or with binoculars.
So why isn’t the flash blue or violet? The answer is that atmosphere will typically scatter most of the violets and blues. Rayleigh scattering is the technical term for this.
At sunset and sunrise times, the refraction and scattering effects are greater than during midday as the sun’s light is traveling the farthest distance through the earth’s atmosphere.
Starfish sunset at Bonefish Point, Providenciales.
For the green flash to be visible, in most cases the above effects have to be further magnified by a mirage, which is usually created by air temperature changes.
A perfectly flat horizon is optimal for sighting the green flash, and because of this many popular beaches in the Turks and Caicos such as
Grace Bay and
Leeward Beach on Providenciales, are ill-suited for the task, as viewed from these coasts, the sun sets behind the high ground of
Blue Hills and
Malcolm's Road Beach.
The green flash is also most likely to occur on a calm day with clear skies.
Contrarily to popular myth, the green flash is a real event that can be recorded by photograph or video. It is not an optical illusion.
Photographing the Sunset
The major difficulty of sunset photography is the limited ability of cameras to capture the full range of light, or dynamic range, from the scene. There’s simply too great of a difference between the bright sun and dark shadows for the camera sensor to record everything.
Most phone and compact digital cameras exhibit this problem apparently, as they can only capture about half the dynamic range that it’s estimated the human eye can observe. This results in photos with an overexposed sun and sky, and a dark detail-less foreground.
Breaking waves at Northwest Point.
In many cases, you’ll simply have to expose for the sky and hope for the best.
The best digital cameras, such as some DSLRs and digital medium format cameras, can actually record a dynamic range similar to what the eye can see and are consequently better suited for sunset photography.
If you have a tripod, try a long expose. This will blur the sharp and disrupting reflections commonly on the water surface.
Use the lowest ISO setting on your camera. The lowest ISO sensitivity typically has the highest dynamic range and least amount of noise (graininess).
Expose for the highlights. Photos from modern digital cameras often have quite a bit of detail in underexposed dark areas which can be recovered. The sun will typically be too bright to capture, but try to ensure that the surrounding sky isn’t overexposed.
Most cameras do a poor white balance job in sunset situations. If you manually set the white balance, you’ll often get more realistic tones.
Try framing you image with or incorporating interesting silhouettes, such as palm trees or a sailboat.
Auto focus may not work in low light. Consider using manual focus.