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Detailed Information on Products
& Technology
SLR's
Canon
Nikon
Fuji
MEDIUM FORMAT
Leaf
Imacon
SCAN BACKS
BetterLight
Metis
DMC
Sinar
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DIGITAL
PHOTOGRAPHY
Digital capture of images
can be divided into 3 major groups. Each group has its purpose
in terms of being best suited for a specific application. The
three groups are:
- Digital SLR Cameras
- Digital Medium Format
Backs
- Digital Scan Backs
Digital SLR's are the same
as traditional 35mm SLR camera bodies except they contain a
CCD or CMOS chip or array, a small viewing monitor and other
electronics. They are great for snapshots and field documentation
because of their portability, and are very economical
and easy to use. However, they use interpolated color (except
for those that use the Foveon Chip) and have limited resolution
in terms of holding fine line work or detail. Medium Format Backs fit onto the back
of Medium Format 21/4" professional cameras. They offer far greater
resolution, come in what is called 1,4,16 shot modes--that is
the back can capture in 1 exposure (native resolution and interpolated
color), in four offset exposures (native resolution and uninterpolated
color), and 16 micro scans (for high resolution and uninterpolated
color). These devices cost in the high teens to mid twenty thousand
dollar range, and the price of the medium format camera and
it lens system has to be added in.Scan Backs fit on the back of large format
4"x5" View Cameras. They provide ultra high resolution and operate
by scanning each potential line of pixels in the original three
times in one pass in RBG. They cannot be used for taking pictures
of moving objects, but are considered the gold standard for
oversized art and general reproduction and technical photography. Some helpful advice on digital color
by:
Color Management for Digital Photography
Robin D. Myers
Better Light, Inc.
In the past, color management for digital photography was treated
exactly like scanning. However, this approach has given poor
results for almost all types of digital photography. Over the
last several years it has become apparent that there are at
least four different types of photography, each requiring its
own approach to color management. These four approaches, named for their application areas, are “pleasing”,
“advertising”, “reproduction with knockout” and “exact reproduction”.
They are presented in order from the least to the most exacting
color reproduction situations.
1. Pleasing
Most of the images taken with digital cameras fall into this
category. These are images made by amateur or non-critical professional
photographers that simply want a pleasing image. Generally the
images are made by using the automatic exposure modes of the
camera. The photographer is less interested in color accuracy
of the produced
image to the original subject and more interested in getting
a usable picture. The sky is blue, the grass green and flesh
tones look good and healthy. For this situation, the color management
profile supplied with the camera should be attached to the image
and
used for subsequent color management. Many consumer cameras
are optimized to produce their images in the sRGB system. If
this is the case for your camera, attach the sRGB profile to
your image. This situation is analogous to the perceptual rendering
intent of ICC profiles. The user does not want to be bothered
with the details of why it works,
just the results; a good, pleasing image.
2. Advertising
This method is usually used for situations such as advertising
photography where the photographer exercises his creative judgment
and style to produce the image required by the client. Exact
reproduction of the original object is not necessary. The image
exposure, tone curve and other parameters are adjusted to give
the desired effect as viewed on the camera or computer monitor. For advertising photography, attach the monitor profile to the
image. The master image the client wants is not on the set,
but the version appearing on the monitor. The camera has been
adjusted to give the desired image in color values for the monitor.
3. Reproduction with Knockout
Images made for catalogs need to have the color close to the
original but are often shot on white surfaces to allow for “knocking
out” the background. This allows the background to be removed
from the image or to superimpose the subject with other images.
To knock out the background, the image often must be made to
produce neutral
backgrounds although the background material itself may not
be spectrally neutral.
The best way to accomplish this goal is to start by creating
an ICC profile for the exposure situation. The ICC profile has
the ability to make the background neutral while maintaining
the color as accurately as possible. This mode is selected as
the “relative colorimetric” rendering intent. Begin by setting
the exposure, ISO, capture time to give
a good exposure. Gray balance on the background to be “knocked
out”. Then make an ICC profile for this set of conditions. Attach
the profile to the image and select the “relative colorimetric” intent to tell the color management system to keep the background
neutral, but the colors accurate.
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Academic
Imaging Associates
P.O.
Box 192, 172 Carlen Street
Manchester Center, VT 05255
V 802.362.3169 F 802.362.0760
Academic Imaging Associates
Manufacturers of Technology, Lighting and Devices
of Interest to Digital Libraries,
Archives, and Scientific Institutions
BetterLight, Jenoptik, Metis, TTI Tarsia Technical Industries, AIAXact, Creo, Sinar, Kaiser, Linhof, Rollei, Schneider, Rodenstock, Imacon, PhaseOne, Nikon, Fuji, Microptics, Zig-Align, Kodak, Leaf, Cruse, Bogan, Bessler, Bassant, Zeiss, Sony, JVC, Braun, Kigamo, Kirtas, I2S D-Line, I2S Digibook, BookEye, Bhul, North Light, Dessanti, nNovia, Novoflex, Bogan, Panoscan, Canon, Comprehensive, ProVideo, Panasonic, Cambo, Epson, Contax, Colortrack, Eldim, Pixera, Riser, Hasselblad, Mamiya, Image Access
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