Pastel Q&A | How To Understand Color Theory; Converting Digital Images to Slides

Q. Having bought a new digital camera, I’m curious: Have you ever tried getting a digital photo converted to a slide? I’ve found Web sites that advertise that they can convert a digital photo to a slide suitable for submitting to art competitions. One site claimed that a 5 MP photo would make an adequate slide; another recommended having an 8 MP photo. Does the process really work?

A. I’ve been producing my slides with this method for several months now and it’s quite satisfactory, though there are a few things to keep in mind. First, you need a good digital camera that will take pictures at a high enough resolution. While every camera is a little different, you have to choose a setting that gives you a minimum of 2,000 x 1,500 pixels for a 35 mm slide. Higher settings will work but probably aren’t necessary. You’ll need to take the photographs with the same care regarding lighting, position of camera relative to painting, and so on, as you would with a camera using film. Then decide whether to use a service you’ve found on the Internet or a local one. I found a local service by asking my photo lab; some photo labs may even offer this service or they can make a recommendation. Carefully review the specifications for how the image is to be submitted; each company may have different requirements for size and format.

The next most important thing is to be sure that your image is an accurate reflection of the actual work. I have a color-calibrated monitor on the computer and set the painting beside it. I crop the image on the computer, so no extraneous materials (tape, backing board or other items) are visible, and only the image of the painting appears. Then I run a test print on my color printer. If you’re using a slide service for the first time, I’d recommend doing a test slide. Compare the slide to the test print and to the image on your screen, as well as to the actual painting. You can thus determine if what you see on your screen and/or the test print will give you an accurate slide.

I really like this method, as I have a high resolution, high-quality camera. I can preview the images before sending them out to be processed as slides to make certain that they’re the best quality, most accurate images possible. Checking the digital image against the actual painting saves money wasted on bad slides, and saves time in masking images. As a bonus, I always have a good digital image of each painting on file, ready to convert and upload to my Web site or to send to a potential buyer via e-mail.



Q. What does color theory mean for the pastelist, particularly since we’re not mixing color but layering it?

A. Color theory is about much more than mixing. For the pastel artist, the theories of contrast are very important—contrasts of color, of light and dark, of warm and cool. The use of complements and of simultaneous contrast comes to mind, as well. Contrasts of color, whether the simple contrast of strong colors such as red and blue, or of complements such as purple and yellow, are important to the color design of a painting. [Fig. 1] Contrasts of light and dark and of warm and cool are used to suggest, among other things, the effects of distance and aerial perspective. In general, in a landscape, colors in the distance are cooler and lighter in value than colors closer to the viewer. [Fig. 2]

Figure 1

Figure 2

The principle of simultaneous contrast refers to the fact that some colors seem to lose their intensity when placed next to each other. Conversely, some colors (such as complements) become more vivid when placed alongside each other. Simultaneous contrast applies to the strokes of color placed near or surrounded by other colors. [Figs. 3 and 4] You should take this principle into account when using pastel on a colored surface, as the underlying color will influence how intense or muted the subsequent layers will appear.

Figure 3

Figure 4

In addition, while pastel artists don’t mix wet pigments before applying them, we certainly utilize the optical mixing of colors on the surface. Small bits of broken color—various colors of similar value—placed next to each other will be optically mixed by the viewer’s eye and may seem to be a different color. [Fig. 5] Pointillists such as the Impressionist-era painter Georges Seurat (1859-1891) utilized this theory, as do contemporary pointillists.

Figure 5

Figure 6

The same colors, in larger blocks rather than broken up, look entirely different next to each other. [Fig. 6] For more information on color theory, I recommend the book The Elements of Color by Joseph Itten, translated by Ernst Van Hagen, edited by Faber Birren (1970, John Wiley &Sons).


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