Digital Photography and Color - Saerghe Parker

Digital imaging has made leaps in popularity since the first digital cameras appeared five years ago. Digital cameras are quickly gaining on conventional film cameras in sales among the average user. By using a digital camera, a person can produce an image that a computer translates into a "series of notations or bits of information" (Krejcarek 4). The camera’s ease of use, speed, and controllability are a few factors that have contributed to its popularity (Butkowski 14). But the professional or amateur photographer may be interested in knowing how well the digital camera is able to capture color in comparison to a film camera. In this paper, I will primarily deal with this subject. But first, I will discuss exactly how a digital camera composes a visual image in comparison to a film camera.

It should be noted that digital cameras and film cameras go through a few similar steps in order to produce an image. Both use a camera lens to focus incoming light. Also, they both use shutter speeds to control the length of time that light enters. Finally, they both capture the image on some kind of "light sensitive medium" (Butkowski 21). Once the light is captured, the two cameras use different methods to create the image. In order to produce color, both have to record the individual wavelengths of light they receive and somehow use that information to portray different colors. The difference between the two cameras’ methods has to do with the kind of light sensitive medium that each uses.

A film camera creates black-and-white images by capturing the light on a light-sensitive material coated with silver-halide molecules. These molecules react with the light to become areas of black metallic silver and form an image on a negative. Color film contains dye layers in addition to the silver-halide layer. Each dye layer is sensitive to certain intensities of light, whether the light is blue, green, or red. Color images are produced by pairing each layer on the film with a dye layer of the exact opposite color and then adding transparent dyes that produce a positive image. The addition of these dyes forms the positive by subtracting appropriate colors from the transmitted light (Butkowski 21).

The digital camera goes through a quite different process after it captures the light for the image. The light-sensitive medium used by digital cameras is called a charge coupled device, or CCD chip. The chip is used to measure and record light energy inside small storage spaces called pixel areas. The light intensity is measured by means of electrons being freed from the CCD chip when light passes through it. The electrons are drawn together by a positive charge that is applied to the electrodes in the pixel. The brighter the light is, the more electrons that are drawn together. Then, the CCD chip converts the light intensity information into digital values corresponding to the number of electrons in each pixel. This information is stored either in the memory of the camera, or on a removable disc or cartridge. Once this is done, a computer can read the digital information, convert the digital values in the pixels to colors, and reproduce the image! (Butkowski 22)

Now that we know how each type of camera creates the image, the question is: "Which camera does a better job of accurately capturing color?" In terms of resolution or image detail, a 35-mm film camera still outperforms the consumer digital camera. Most consumer digital cameras come with a CCD chip of either 2 or 3 megapixel resolution, referring to the amount of detail that the chip can handle. According to PC Magazine, the low-end "digital cameras still aren’t fast enough or crisp enough to handle every shooting opportunity that comes along(PC Mag 180)." The acuteness of the resolution is still better with film (Krejcarek 29). However, professional photographer Joel Butkowski points out that some high-end digital cameras can match or exceed the quality of film, capturing 40 million pixels of information in comparison to the 25 million pixel resolution of the 35mm slide film (Butkowski 18).

 

 

An advantage that Butkowski emphasizes is the increased image control that the digital camera allows which leads to improved color accuracy. He uses the example of pre-testing film in order to check for any color casts inherent in the film. This is usually only done by photographers who must have a very accurate portrayal of color, perhaps for a clothing catalog. Since, certain types of film are noted to produce "either warm or cool tones", each color layer in the film must be tested to see if one color is more dominant. If a color imbalance in the film is recognized, a color-correction filter must be placed over the camera lens to compensate for the color cast. This entire process may take an entire day to complete, but there will always be a color-shift variation of about 2 percent to 5 percent. On the other hand, digital cameras have built in software that automatically balances the color to remove any color casts. Even if the automatic color-balancing doesn’t produce the desired accuracy, the user can simply look at the monitor and make necessary adjustments right after the picture is taken (Butkowski 16).

The color manipulation that digital photography allows is a definite advantage over conventional film for the creative photographer. In a matter of minutes, the user can use an image-editing program to change the background color, create linear or radial blends from one color to another, and even convert black-and-white photographs to tones of a certain color! (Krejcarek 81) This allows a person to experiment without worrying about the cost of film. Images can be copied without losing resolution (Krejcarek 8). Any unwanted changes that are made to an image can simply be undone using the editing software. This allows the photographer to become more of a designing artist.

Currently the best consumer, low-end digital cameras seem to be the 3-megapixel cameras. The are reported to take "excellent still photos in well-lit, daytime scenes" (PC Mag 179). However, due to the higher level of detail of the average 35mm film camera, film is not dead by a long shot. Therefore the consumer that is concerned with getting a crisp, high-resolution shot is probably better off sticking to film. But for those who want to be able to manipulate the color of their images after the shot is taken, digital cameras offer a decided advantage in error correction and creativity.

 

Jeff Sasson of Kodak Labs - 1st digital camera
1975

Works Cited

  1. Butkowski, Joel, and Andra Van Kempen. Using Digital Cameras. New York: Amphoto Books, 1998.
  2. Krejcarek, Philip. Digital Photography – A Hands On Introduction. Albany: Delmar Publishers, 1997
    3. "Digital Cameras – Is Film Dead?" PC Magazine. 7 Nov. 2000: 179.