This is a great article written by Justin W. Moore, that I found that definitely needs to be included on this site.

Water is life. The existence of nearly everything living is critically linked to its availability. In and near the streams, rivers and oceans of our world, Nature thrives. It is no surprise that such a powerful force in Nature is so often depicted by the outdoor photographer. This tutorial provides basic tips that will help you capture the beauty of water in your photographs.

Use Slow Shutter Speeds

Slow shutter speeds create a soft, artistic portrait of water. Generally, shutter speeds that are 1/6 of a second and slower will yield the best results. A majority of my waterfall photographs fall between 1/4 second and 3 seconds of exposure. The key here is to dare to experiment and not be afraid to shoot a lot of film or frames. You never know what shutter speed is going to render the waterfall the way you see it in your mind’s eye. Needless to say, you will need your tripod when making these long exposures. It’s just one more reason to save your money and buy a good quality, full-featured tripod!

Watch Your Exposure

Why? Because waterfalls usually reflect a lot of light that is going to fool your camera’s built-in exposure meter unless you compensate. I usually find that spot metering off of something neutral in the same area (and thus in the same light) works best; rocks, tree trunks and grass are usually good candidates. To learn more about properly exposing your photographs, see my tutorial Commanding Exposure.

Arm Yourself with Some Useful Tools

Your camera equipment should include a circular polarizer and/or a neutral density filter. A polarizer can increase the overall color saturation in the scene as well as decrease your shutter speeds by 1.5 to 2 stops (a good thing if you find yourself battling a rising sun with an overall increase in lighting). Slowly rotate the polarizer to witness the effect it is having on your scene. Depending on the lighting conditions and your position relative to the sun, you may or may not decide to use it. A neutral density filter can also be used to reduce light input by up to 2 stops in most cases (depending on the strength of the filter).

Use a Slow Speed Film / Low ISO Setting

Using a slow speed film or low ISO setting (ISO 25 to ISO 100) on your digital camera will enable you to photograph waterfalls with a variety of long exposures. Slow speed films like Kodak’s Royal Gold 25 or Fuji’s Velvia will also reward you with incredibly fine grain and outstanding color saturation.

Take a Deep Breath

Don’t let the sheer beauty of the scene get you so excited that you forget everything else I’ve mentioned and come home with a roll or two of underexposed disappointments. Believe me, I’ve been there! Being close to something so beautiful and grand can sometimes lead to temporary lapses of good photographic judgement. Think about every exposure. Bracket your shots and don’t fall prey to mindless “machine gun” shutter clicks.

Use of a circular polarizer can allow you to attain a slow shutter speed for scenes such as this one of Pedernales Falls. A polarizer also removes most of the glare from the scene.
Kodak Gold 100 exposed for 1 second

Nature photography: How to take great nature photographs

Great nature photography explores the natural setting, records natural history and the facts and phenomena of nature. Nature photography should not contain images of man or man’s presence, such as power lines, automobiles, radio towers, etc. Nature photography records organisms, weather, animals, natural landscapes and any aspects of the natural environment.

For a photograph to be a “nature photograph” it must completely fit the rules for nature photography. Nature photographs cannot be “arranged” in any way. There should be no manipulation of the scene to convey a message. The content of a nature photo can be purely pictorial or can relate a story or information about nature or natural history. Nature photography’s subject may be an abandoned beehive or the reflection of trees in a stream.

Subject or theme. To compose a nature photograph, it is helpful to see the order present in the disarray of the natural scene. Look for rhythm and pattern, and what doesn’t fit the rhythm and pattern. What stands out in a sea of fallen leaves?

Format. Decide on a format for your photo – horizontal suggests expansiveness, vertical suggests height, and square is neutral.

Fill the Frame. Fill voids with clouds, branches or other naturally occurring objects. Try to allow enough space around the subject that the viewer can explore around the subject in the frame. Aim to capture the whole of the subject in the photo. If not possible, aim to convey a sense of completeness in the image you capture.

The Rule of Thirds. Imagine dividing your picture area into thirds horizontally and thirds vertically. Where the lines intersect are the “thirds” – the area next to the direct center of the frame. Center your subject on one of the “thirds” to give more interest and movement to your photo.

Look for Lines and Shapes. A meandering stream, a curled fern frond and a row of corn all give strong lines to the composition. Some items are triangular, round, square, etc. A butterfly is triangular, a leaf oval. Look at the scene you want to photograph in terms of balance of line and shape.

Texture and Pattern. Texture and pattern add dimension and can sometimes give an abstract quality to the photo.

Perspective. Create the illusion of distance and depth through capturing close foreground objects within the scene depicting distance, or vice-versa.

Viewpoint. Take the photos of the acorns at ground level, or climb the tree and capture the squirrel at branch level. Take photos with the viewpoint of the insect or bird. Use the zoom feature to get close to the leaf spores or the sand crab.

Color. Pay close attention to both the subtleties and drama of color in nature. The same scene saturated in green in the early morning turns brown, green and blue at noon.

Equipment. Great nature shots have been taken by observant photographers with nothing more than just a simple instant camera. Equipment that is recommended, however, for the serious-minded consists of an SLR camera, light filters, lens shade, tripod, and light meter.