Reply #17: It depends...

[regnaD kciN]

I would have thought that the ISO would have been higher to catch the water in motion like that without blurring.

The ISO isn't something that works in isolation -- the key factor is shutter speed, which is related to both the ISO of the film/digicam and, of course, the amount of light available.

For example, the first few of my photos were taken on the nature loop downstream of the falls. In that area, there was a lot of tree-canopy cover, and hence relatively little light. I had to bump the ISO to 200 to get a shutter speed of 1/60s, which is really the slowest you can go and still be able to handhold steadily. I didn't want to take it to a higher ISO, because most digital minicams, including the 5700, are subject to chroma noise at 800 or even 400.

In the first two shots, both taken at 1/60th at ISO 200, you'll notice the moving water looks different from in the other shots -- it's much more of a soft white blur. This is the effect of the 1/60s shutter speed.

Moving down to the third picture, you will see that the path had moved away from the tree cover, and so I was able to take the ISO back to 100 and shoot at slightly under 1/125s. If you look clearly, you'll see somewhat more texture to the white sections of the water, because it's being "frozen" a bit more by the faster shutter speed.

Leaving aside the non-water photo that follows, the remainder of my posted pictures were taken in bright enough conditions that I could keep it at ISO 100 with shutter speeds ranging between 1/270s and 1/390s. At those speeds, the water is really being caught in mid-motion, resulting in being able to see virtually each drop of spray.

If you wanted to catch the water like that in shadowy conditions, of course, you'd need a higher ISO to be able to shoot at a decent enough shutter speed. In which case, I would also recommend not using a minicam, even a good one like the 5700, and going instead with a high-quality D-SLR whose larger sensor can, in some cases, give you noise-free images even up to ISO 1600.