what are the most commonly used filters for black and white landscape photography. Also what is the best way to deteminne which filter to use for the maximum ammount of contrast.

-- Del Storvik (eelor@ccinet.ab.ca), August 29, 1999

Answers

There is a good number of filters to deal with. I suggest checking out the Ansel Adams book, "The Negative" to get a good idea of what is generally used and what effect they have. Another point of view comes from Fred Picker who says, "if you are going to use a filter, make sure you get an exposure without one, so you'll have something to print".

-- chuck k (kleesattel@web.com), August 29, 1999.

Del, the following might serve as a guide, but I urge you to purchase a basic b&w book, or even more daunting, Ansel Adams' Natural Light Photography book, #4 in his classic Basic Photo series.

One of the difficulties when you talk about filters is how to refer to them. We may speak of a yellow filter, a K2 filter, and a Wratten 8 filter, and be referring to the same thing. Some of these labels come from attempts by Kodak and others to standardize the naming of filters, and other posters may know the arcane history better than I. I'm going to refer to the color of the filter as the most useful method.

For b&w photgraphy, the most common filters used are yellow, orange, green and red, as well as haze and polarizer. The usual reasons filters are used is to alter the appearance of skies, water, and foliage to a more natural appearance (note the subjectivity). A filter works by absorbing the complement of it's color - i.e. a yellow filter is the complement of blue, so it absorbs the blue light but transmits to your film the yellow light. This underexposes for the blue light, rendering the skies (blue skies, right?) darker due to underexposure. You can combine filters to achieve a specific effect.

Red filters absorb blue and green light waves, darkening the sky dramatically. Orange filters darken the sky and water more than yellow and less than red, and also reduce atmospheric haze. Yellow filters darken sky and water as well. Because yellow has the least dramatic effect, the result is considered more natural. Also good for foliage.

Hope this helps. Also, you'll have to compensate your exposure for almost any filter other than Haze. For instance for a yellow filter you generally expose a full stop more, for a red filter 2 stops.

-- August Depner (apdepner@uswest.net), August 29, 1999.

If you can only have one filter for B&W work, the red (25A)is the one. The dramatic darkening of the sky will enhance almost any landscape. If you are lucky enough to have a day with a "photographers sky", the rendition of white clouds with a 25A can be truly breath-taking! Of course a 25A is mandatory for Infared Films. I have a set of 25A filters to fit all of the lenses in all three of my equipment bags.

-- Gene Crumpler (nikonguy@worldnet.att.net), August 30, 1999.

The medium yellow (K2) filter can be considered the default filter for outdoor photography because most B&W films are overly sensitive to far blue and ultraviolet light. This is mentioned in many Kodak data sheets. The red filter dramatically darkens the blue sky but it costs 3 stops of speed and it darkens green foliage. The orange filter darkens the sky considerably but does not darken foliage and costs only about 1.7 stops. It also reduces blemishes on portraits but can make caucasion skin look ghostly. A polarizer can also darken the sky when the sun is to the side but can give uneven effects with a wide angle lens. A polarizer can also reduce haze and water/glass/leaf reflections. My favorite combination for punching up a landscape is the orange combined with the polarizer. The green filter lightens foliage, darkens the sky skightly and accentuates facial blemishes.

-- Tim Brown (brownt@ase.com), August 31, 1999.

Filters are used to change a scene by absorbing some light, and allowing other light to pass.

Start with a yellow and a red filter. Those are the two most common. Then buy an orange, and a green. The Tiffen filters in the bubble packs will have the most commonly used colors. Tiffen filters come with a tiny pamphlet describing the basic filter effects.

Contrast from a filter comes from blocking the blue light in shadows. Orange or red will give you the most contrast. Contrast also comes from using faster films (ISO 400) and "push"-processing them for higher speeds. For instance, load up your camera with a roll of 400, set the camera for 800, shoot it as normal, and then have it processed. The contrast will increase.

IR photography comes alive with red 25A and deeper red filters. The 25A (B+W 090) is good, but I recommend you use a B+W 091 (Wrattan 29) or B+W 092. These darker filters work well with Konica IR 750 and Ilford SFX 200. The Kodak HIE produces far more radical IR effects, but it requires very careful handling. Ilford and Konica can be easily processed in the majority of commercial film processors.

The Ilford and Konica films produce better effects with the darker filters. When I use a 25A, deciduous trees and grass will turn white, while conifers stay black. The B+W 091 (Wrattan 29) will cause the conifers to turn grey, and depending on the species, some conifers will remain black. The B+W 092 will turn both conifers and decidous trees white. Ilford produces an opaque filter for its films, but you need a gel holder for it.

-- Brian C. Miller (brianm@ioconcepts.com), August 31, 1999.