PhotographyTips.com - the #1 guide to better conventional and digital photography Become a Member iPhone Posing GuideGuide to Posing the Female Model BookGuide to Posing the Model CD
Search
Login

Member Login

Find us on Facebook
Follow us on Twitter
Find us on Flickr
Connect with us on LinkedIn

SPONSORS

Sell Photos Online

FEATURED SITES


Black and white film

and its sensitivity to color


Black & white film is available in many varieties and film speeds, including film like Kodak's T400CN that can be processed in C-41 color film processors, which are typically used at one-hour photo labs.
Black & white film is available in many varieties and film speeds, including film like Kodak's T400CN that can be processed in C-41 color film processors, which are typically used at one-hour photo labs.

Black and white film records colors in shades of gray that vary in their brightness. Depending upon the black and white film’s particular emulsion (its spectral sensitivity - how accurately it renders the brightness levels of colors in a scene), colors can be rendered in differing shades of gray or not recorded on the film at all. Black and white film is available in different negative emulsions for different purposes. The choices are as follows:

PANCHROMATIC FILM

The word “panchromatic” means sensitive to all visible colors, and film of this type is, to a large degree, sensitive to all the colors of the spectrum. We say “to a degree” because no black and white film will simultaneously translate all colors into absolutely-perfect corresponding shades of gray. Panchromatic or “pan” films, which are the most popular of the black and white films, will generally render red and blue as lighter than they appear, and will render green as darker, idiosyncracies that can be overcome through the use of photographic filters. A medium-yellow filter will cause this film’s sensitivity to color to be quite close to what we ourselves see in a scene.

Since panchromatic films will record all colors, they must be developed in total darkness. Any color of light would fog them. Because they are sensitive to all colors, they are the best general-purpose black and white film.

Panchromatic film, the most-popular type, is sensitive to all colors.
Panchromatic film, the most-popular type, is sensitive to all colors.

BLUE-SENSITIZED FILM

This is a specialty black and white film that is totally-unsuited to general photography. Blue-sensitized film is sensitive only to ultraviolet radiation, violet and blue, which is registered as white. These are the shorter wavelengths of light. It simply doesn’t “see” other colors (red, orange, yellow and green), and therefore doesn’t record them, so these colors appear as black on the print. This type of film is used for astronomy, photoengraving and other special purposes. This type of film can be handled under red safelights without fogging. Blue-sensitized film is also known as “non-color-sensitized” film.

ORTHOCHROMATIC FILM

The word “orthochromatic” means “representing correctly the relations of colors as found in a subject,” but for a photographic film’s emulsion, it means “sensitive to all visible colors except red.” This film emulsion type renders red as black in the final print.

Orthochromatic, or ortho film almost, but not entirely, renders the brightness of colors in correspondingly-bright shades of gray. Blue is the problem for this film emulsion. It is rendered lighter than it should be, a characteristic that can usually be corrected with a yellow filter.

There's something about black & white film that captures mood and emotion better than color film in many situations. Perhaps color distracts our eye from a picture's essence. Or perhaps our most emotional dreams are in black & white. What is B&W's allure?
There's something about black & white film that captures mood and emotion better than color film in many situations. Perhaps color distracts our eye from a picture's essence. Or perhaps our most emotional dreams are in black & white. What is B&W's allure?

When would you use a black and white film that renders red as black and requires a yellow filter to correctly record the relative brightness of blue? Think of skin tones and portraiture for one answer. Reddish or pinkish skin tones are rendered darker than their actual brightness values with this film, often improving the subject’s appearance. But, that is not their only use. Since the film’s emulsion is insensitive to red, it can be developed in a darkroom with a red light on, and the photographer (actually, the person doing the developing) can see what he or she is doing. This is a big advantage to the beginner who has trouble feeling his or her way around in the dark with panchromatic film. You can handle these types of films under red safelights. The spectral sensitivity and the speed of the particular film determine the safelight filter that you need. The drawback to this type of film emulsion is that it just doesn’t record scenes as well as panchromatic film does, which has better color rendition and smoother shades of gray. It is generally cheaper, though.

INFRARED FILM

Think of this black and white film emulsion as a panchromatic film that has been extended to have increased sensitivity to red light beyond the visible spectrum, i.e. infrared light that we cannot see, but that the film does. Infrared radiation has some unique characteristics that make using this film interesting, fun for experimentation and great for special effects photography. “Like what?” you say. Well, heat radiation can be picked up on infrared film, for example. So, you can photograph a hot frying pan on infrared film in what to you is total darkness. Infrared light can penetrate haze astoundingly well, making this film quite useful in long-range photography with telephoto lenses. You can often photograph a long-distance subject quite well even though it is invisible to you because of atmospheric moisture. It is very useful in aerial photography where atmospheric haze and moisture are too dense for other films.

But infrared film also depicts colors in unnatural ways, making it unsuitable for general black and white photography. It depends on the degree to which the subject reflects or absorbs infrared light, and since you can’t see infrared radiation, you can’t easily predict how light or dark something will appear when photographed with this film. But, it can still be fun to experiment with because of this characteristic. Blue will become black when photographed with infrared film, so the sky or the blue surface of the ocean (which absorb infrared radiation) will be photographed as uncharacteristically dark - quite black, even. Green, on the other hand, appears bridal veil white. Leaves and grass take on an ethereal or ghostly look because they reflect most infrared radiation. And don’t forget, infrared emulsion film is also sensitive to visible light, making its results even less predictable. For a real infrared effect in your photography when using this film, try a deep red filter, which excludes just about all visible light and therefore records infrared light only - light you cannot see. Check the data sheet that comes with infrared film for instructions and filtration guidelines. (For more information, see Infrared film.)

High-speed panchromatic black and white film is great for stop action photography, and has great exposure latitude, making it ideal for sports pictures. A yellow-green filter was used in making this picture.
High-speed panchromatic black and white film is great for stop action photography, and has great exposure latitude, making it ideal for sports pictures. A yellow-green filter was used in making this picture.

 
Related topics...

Processing black & white film