Filters In Black & White Landscape Photographs

 Filters In Black & White Landscape Photographs

by William Lulow

There is nothing like a nice, crisp monochromatic image of some landscape to really make you sit up and take notice of it. First of all, we see things in color everyday, so Black&White calls attention to itself BECAUSE it doesn’t contain any color. That’s just the point. When you shoot in original Black&White, all of the colors can be altered by using FILTERS over your camera’s lens. But you have to know a bit about the color spectrum and how each color filter alters the colors of things in the real world and reproduces them in shades of gray, white or black. The reason for using them is to enhance the look of the Black&White photographs and to make them really be beautiful “works of art.” All the great landscape photographers have used filters to create beautiful images.

Filters usually come in red, green, yellow, orange and “neutral density” shades, this last one only changes the exposure but doesn’t alter any colors. If you are shooting in Black&White, these filters can yield several interesting and dramatic effects.

These are some of the effects you can get from using color filters in monochrome mode with your digital camera. Light can be broken down into certain wave lengths. There is a VISIBLE portion of the electro-magnetic spectrum that includes radio waves, television waves, x-rays and infrared light. The light that is visible to us consists of waves that go from red to dark blue. The thing to remember for photographic purposes is that filters will pass wavelengths of their own color and block those of its complementary color. So, let’s say you were shooting some Black&White film.  Remember those negatives? If you were shooting a scene with B&W film and a red filter and the scene had a dark blue sky, the filter would pass light on the red end of the scale and block the waves from the blue end. That means that on the NEGATIVE, the blue sky would be clear, as it would receive no light rays. When you went to make the print, the sky would be black while the rest of the scene would be altered slightly. Anything red would be LIGHTER and objects in the middle of the spectrum would be altered depending on how much light was blocked. Again, in that case, anything that had some blue in it would be represented as black.

Depending on the color of the filter you use, colors in the scene would be rendered in various shades of gray or black and can range from very dramatic to just separating colors from each other. As you can see by the above examples, the images with filters on the reddish side of the spectrum come out much more dramatic.

Here is a representation of the electromagnetic spectrum:

You can see why the filters in the reddish category have the most dramatic effect on Black&White images. Now when using these with digital imagery, you don’t have to be concerned about negatives because you won’t be using any. But it’s important to be aware of how these filters work. You can also alter your images with digital filtration technology that is built right into your camera. Having experimented with this, I have found that nothing works quite like shooting in original Black&White (in monochrome mode) because it gives you beautiful originals from which to work. Also, the digital filters available with most cameras aren’t as impressive when it comes to rendering blue skies black. Here’s another example:

This image was made with a red filter over the lens in MONOCHROME mode on my digital SLR. The sky was rendered close to black and the green trees were a bit darker as well. Yet another one:

Here the sky was a bit darker in its blue color, so the filter worked even better here. Notice how the white portion of the ships just seems to pop out of the dark skies!

Now whenever you add a filter over your lens, you will cut down on your exposures. Each filter has a FILTER FACTOR which, in the days of film, would let you know how many stops to open your lens to compensate for the light the filter would block. The red filter (25A) would usually take three extra stops and the others somewhat less.

So, if you decide that you want to use a red filter, which might require a 2.5 f/stop factor, you would have to choose how you were going to accomplish this. You could open up the aperture, slow down the shutter speed or increase the ISO setting, or maybe a combination of all three. But, if you were trying to get as much detail as you could in your image, you might want to use a small aperture (f/stop) to obtain greater depth of field and more clarity. If that’s what you were after you would then need to increase the ISO setting or slow down the shutter speed a bit. If you wanted the most clarity, a low ISO setting would provide that, but then your only means of exposure compensation would be a slower shutter speed. If that was the case, and all the other requirements of your exposure were to be met, you would need to place the camera on a tripod to use a slower shutter speed. All the exposure elements work together to make the image what you wish it to be.

One other filter I have become very fond of using is a neutral density, gradient filter. It looks like this:

It is clear at the bottom and dark at the top. It is used in a special filter adapter that attaches to the camera’s lens. Neutral density filters are handy because they do not alter any colors the way some the filters above do. They do enhance the blue skies however, while leaving the foreground normal. This can provide some really dramatic scenes in color:

Here you can see what a nice, deep blue color the sky is rendered. The clouds also stand out. This was made with my normal, ND gradient filter. I almost always use this filter when I am just touring around looking for landscape images. It really makes many images much more dramatic.

But, it’s the Black&White images that become the most dramatic when you use filters so, I always travel with my filter pack that consists of a red filter for landscapes, several ND filters of various shades for cutting down exposure times and my gradient filter. This way, I am prepared for just about any scene that strikes my fancy.