Neutral density filter
August 11, 2011

Recently, I posted regarding circular polarizers used in digital photography. The purpose of the specialized filter is to cut through glare and produce higher contrast. This could be used in landscape as well as water images. Lately, however, I have been interested in another style of photographs that cannot be achieved with just the polarizer.

I was looking for time-delayed day images that are difficult to compose in bright daylight with a standard setup. Time-delayed photographs basically involve lower shutter speeds. Here motion can be captured to enhance the intensity of a wild landscape. Normally, in order to decrease the shutter speed, the aperture needs to be closed as much as possible. Unfortunately, this affects the depth of field and a deep depth of field may not be required or preferred. Here, neutral density (ND) filters present a solution. ND filters are colorless pieces of coated glass uniformly shaded to cut down light and are available in square and circular formats. With this piece of extra glass, the photograph can be taken at a shallower depth of field and still capture motion.

My first tests at the ocean during sunset were unsuccessful simply due to the sunlight's intensity. I had thought that the wave activity would help me achieve my goal even in bright sunlight, but unfortunately, the ND did not sufficiently stop down the light. The result was unsatisfactory with waves still appearing individual while overlapping each other, similar to a multi-exposure overlap. Once I find the proper environment to use this particular filter, I can post some pictures.