I love to play around with shutter speed and water. This waterfall drops into an enclosed cavern, it was so dark I had to use a very slow shutter speed and tripod, but I love the way a slow shutter speed makes the water seem so majestic.
ISO 400, 0.3/sec @ f4.8
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ISO 400 0.3/sec @f3.5
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My compare and contrast photo. This is a faster shutter speed with the flash. The flash lights the foreground, but it shows how dark the cavern really is.
ISO 400 1/60sec @ f3.5 w/flash