|
Digital Imaging : Digital Headache
DIGITAL HEADACHE
Need an aspirin?
Excerpted from Nielsen's Tricks for the Digital Camera in Reaping
the Benefits of Digital Photography by Greg Rice in the August 1997 issue of Electronic
Publishing.
- Exposure:
A third of a stop is important. Capturing the image right up front should be everyone's
first goal.
- Filters:
Filters are important with digital camera, and for different reasons than they are with
traditional cameras. Polarizers and starburst filters don't work as they do with film. A "hotmirror"
filter is essential to reduce infrared sensitivity.
- Optics:
It's important to find the optimal f/stop for each lens. "The 60mm Nikkor Macro
is the greatest lens made for digital imaging", Nielsen says. It has a maximum aperture
of f/32, but he tries to shoot at f/11 or so. When he shoots with the Kodak Professional EOS-DCS
1 digital camera, he uses an 85mm f/1.2 lens, again at f/11 or so. Using smaller apertures softens
the image because of diffraction, even though the image has more depth of field.
- Lighting:
Give up any hope of using lens flare as a creative tool. Charge-Coupled Device (CCD)
sensors don't respond well to light sources shining directly into the lens. So Nielsen always
positions lights no more than 180 degrees off the camera axis (6 o'clock and 9 o'clock). He's
also very selective about the color and quality of light he will use. For flesh tones, he uses
gold reflectors to pick up the yellow factor in the digital file. The reason: the blue channel,
which forms the yellow image, benefits from a stronger signal.
- Post processing:
After capturing an image and acquiring it in a desktop computer, Nielsen performs post
processing in Adobe Photoshop. He also adjusts the tonal range (printer values of about nine
for blacks and 240 for whites) to make the image reproduce best on press.
|
