Recently, on our field trip to the Essex steam train area, a couple of people asked me about the blown out sky in their waterfall images. The day was not ideal for waterfalls at all because it was a sunny clear day; but there a couple of ways to control the blown highlights in the sky when you are in a location and can’t return to shoot on a cloudy day. The answer to this dilemma is to use filters; and sometimes, even with filters, it is difficult to photograph at midday.
Filters (on camera) can often save an image but more than that, filters will improve a shot dramatically.
The next two ND graduated filters are basically versions of the same idea. Graduated neutral density filters control the brightness of the sky and bring your exposure under control when the sky is brighter than the foreground beneath it.
The next two images will give you an example of the 3 stop ND filter..the first one was taken without the filter, the second one with a filter..the clouds and sky become more prominent and visible. The exposure is more controlled.
Another filter which can be used creatively is the solid ND filter. I have a 3 stop, 5 stop and a 10 stop. I use the 5 stop much more frequently than the 10 stop, although in the middle of a bright day, with fast moving clouds, a 10 stop can create a fascinating image when converted to black and white…the images below were taken in three different ways: the first one is at 1/300 second with only a polarizer; the second one is a little slower at 1/2 second with a 3 stop solid ND, the last was taken with the 5 stop ND and needed 36 seconds exposure. You can see how the color shifts as you use a neutral density filter..it usually has a little blue shift, even in bright daylight…there are some cheap filters that are known for magenta shifts; avoid those..the shift is hard to remove. I speak from experience with them. I am aware of the passage of time in each of these images; the last one being later in the afternoon, but they are examples of what long exposure can do to water movement.
And do not get screw on graduated ND filters! On a wide angle they will vignette and even worse, you cannot control the horizon: it has to be in the middle of an image. You will need to purchase a filter holder for the filters. This is what they look like but require adapters to fit on your specific lens…with a filter holder the filters can be raised or lowered and even twisted sideways. I have flipped them 180 degrees when the ground is brighter than the sky.
That was a quick refresher; now get the filters and practice or do it the lazy way using Photoshop or Lightroom grads. But I like to see results in camera; it helps me visualize what my final image will look like.
Your comments are helpful and to the point. Have only used a polarizing filter not always successfully.