Expressing motion in photographs is challenging but rewarding process. One needs to become familiar with the movement of the subject before utilizing camera's unique mechanism. There can be a number of ways to express motion such as freezing the action which evokes imagination of the movement in viewers.
Fast
For example, I was watching these monkeys at Jigokutanikoen, a famous spot for monkeys in hot spring water. In the middle of the water, I noticed there was a rock, and monkeys were jumping on and off of it. I could have missed their behavior if I walked away after taking usual pictures of monkeys in the water. Once I caught such action, I had to wait for the perfect moment.
ISO 100 120mm f/2.8 1/1600sec
Another fast shutter speed shot
Big Drag
Long exposure and slow shutter speed: the combination of these two unique characteristics of the camera is probably the biggest reason that I fell in love with photography. A camera is certainly a mechanical tool with a lot of scientific aspects. Digital cameras probably have even more technological elements in them although the elements are mostly hidden inside the camera. Although the naked eye can never view objects in such way, a camera can, and photos with cool effects can be created.
ISO 125 25mm f/7.1 8.0 sec
Longer the Better
There are ND filters to cut down the amount of light coming in a camera. They have numbers which signify the strength of the filter, greater number the higher blocking power. For example ND filter 100 can provide 10-stop reduction in exposure which significantly slows down shutter speed. This is an unconventional way but welder's glass can be a unique addition to the idea of long exposure and slow shutter speed even in a greater level. I'll probably do another post just about this technique. Anyhow, even during daylight by using welder's glass, shutter speed can be extended to 180 seconds. As a result, moving clouds in daylight look similar to the photo above which was taken at night.
ISO 100 14mm f/11 180sec