The day was bright, sunny and cold, with strong, gusty winds blowing huge, billowing clouds across an azure sky – perfect for the kind of images I had pre-visualized in my head before stepping out the door.
It is fortunate that an ideal location for creating such images lies only about three miles from my home: Great Falls on the Potomac River in Maryland.
The 10-stop ND filter enabled me to create such images, even in bright midday sunlight. It’s a dark piece of glass which allows the photographer to keep the camera’s shutter open for far longer than would normally be possible in bright sunlight but without over-exposing the image.
The effect of such a long exposure – the main blog image was 124 seconds – is that movement in clouds and water is captured by the camera’s sensor as motion blur, giving the photographer the power to bend time and lend a surreal look to an image.
While there are well-established methods for calculating a correct exposure while using a 10-stop filter on a regular camera, getting a correctly-exposed image with an infrared-adjusted camera, as I used for the second and third images, proved to be more a matter of trial and error.
This is because the IR camera “sees” through the dark glass of the filter more powerfully than does a regular, visible-light camera. As a result, for the IR images, the shutter was open for only 40 seconds, although the lighting conditions were the same, as were the aperture (f22) and ISO (200).
(Click on an image to enlarge it)