During the recent Memorial Day weekend I went to photograph the 3700 flags on Boston Common honoring Massachusetts residents, from the Civil War to the present, who made the ultimate sacrifice for our freedom.
This was shot mid afternoon and the sun was quite high in the sky. I used a variety of shutter speeds and f stops to achieve different effects. In order to gain a long exposure and have movement in the flags I used a variable ND (neutral density) filter. Longer exposures (slower shutter speeds) allow for more motion in the photograph. As a photojournalist, I am trained to do everything in camera.
ISO: 100. Aperture: 4.5, Shutter: 1/160
ISO: 160 Aperture: 18, Shutter: 1/10
ISO: 50 Aperture: 16, Shutter: 2 seconds
ISO: 50 Aperture: 20, Shutter: 4 seconds.
The photographs above were taken with Nikon D800 70-200mm Nikkor and a 105mm Nikkor Micro lenses on an Induro tripod with a Nikon cable release. I carry my gear in a ThinkTank Photo Retrospective LC2, which is my standard walking around camera bag.
There is no "right" or "wrong" with photography, It is only what you prefer. An ND filter is one of the tools I used to achieve different looks for my photography.