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Technical Information
STANDARDS
Two Cat
Digital specializes in scanning photographs to digital files.
These digital files can then be used for a multitude of purposes:
archival storage, image databases, web viewing, desktop printing,
professional photo printing and offset printing. Here is some
information about our scans:
RGB vs CMYK: There
are many companies that specialize in scanning for offset printing.
These companies will scan to a specific output size and provide
digital files ready for prepress. Most often they provide the
files in CMYK color mode. These scans are fine for printing at
that one size on a particular printing press. However, they are
not ideal for any other purpose, including desktop and professional
level photographic printing. This means that if you get CMYK
scans from a prepress shop, you will need to rescan them later
for any other usage.
We scan to
the RGB colorspace because it is a larger gamut. This means there
is more color information in an RGB file. It is also the colorspace
that is compatible with viewing on a monitor. You can convert
it to CMYK later if you need to, but always save your original
RGB file (use "Save As..." and give it another name)
because you will lose considerable quality if you need to convert
back from CMYK to RGB.
Image File Formats: We scan to either TIFF or JPEG. TIFF
is uncompressed and is the industry standard for highest quality.
Compression causes loss of quality. Since TIFF files are not
compressed, the files are larger and fewer fit on a disc. But
media prices (and hard drives) have come down to the point where
this is no longer a consideration. TIFF is accepted by every
major imaging application. TIFF is the best choice for printing
your files.
For web viewing
and printing through consumer labs (like Kodak, Ofoto, Shutterfly,
etc), JPEG is the most common format. JPEG is a compressed format
and one can control the amount of compression. The greater the
compression, the smaller the file and the greater the loss of
quality. We use the highest quality level when creating JPEG
files. JPEG is also the standard for files coming off digital
cameras.
Media Quality: For
our ARCHIVE, PRO PHOTO CD II AND PHOTO CD II discs, we have standardized
on Mitsui MAM-A Gold archival discs. Mitsui takes archival quality
seriously and accelerated aging tests show Mitsui MAM-A gold
discs will last for 300+ years. We could buy much cheaper media
but that wouldn't be fair to customers expecting to archive their
images on disc.
For our inexpensive
ROLL SCAN CD, we use Mitsui MAM-A silver CD's but offer an upgrade
for a nominal charge.
You get what you pay for with media. Do not trust your important
images to twenty-five cent discs.
Dust and Scratches: We make every attempt to remove surface
dust from film before scanning. We use oil-free, filtered compressed
air to blow the dust off. We also maintain our scanning facility
as dust free as possible with a separate air conditioning system,
HEPA level filtration and humidity control. Our technicians wear
lab coats and gloves when handling film. But sometimes dust is
very hard to eliminate and the sharper the scan, the greater
the problem.
Our latest
scanners utilize Digital ICE technology. For color negatives
and E-6 processed slide film (Ektachrome, Fujichrome), Digital
ICE virtually eliminates dust and most surface scratches. These
scans are so clean that most people do not have to do any dust
removal in Photoshop before using the digital images. This saves
a tremendous amount of time. (Unfortunately, Digital ICE does
not help with black and white film or Kodachrome slides.)
Our older scanners,
like the Kodak Photo CD units, do not have this dust elimination
capability and, despite our best efforts, there will be some
dust cleanup necessary before you can print the files.
Color Management: Our normal procedure is to apply the
Adobe 1998 RGB profile to ROLLSCAN, PHOTO CD II, PRO PHOTO CD
II and ARCHIVE CD scans. On large projects we are happy to use
some other profile. Some people prefer sRGB, although that profile
has a smaller color gamut, meaning there is some information
lost. Of course, you can set Photoshop to ignore the embedded
profile or to convert it to your preferred profile. We just feel
that the Adobe 1998 RGB profile gives you the most information
to work with.
For Kodak Photo
CD discs, the proper color profiles (transforms) come with Adobe
Photoshop. If you need copies of these, or want to make sure
you have the latest (they last changed in 1999), you can download
them here: PHOTO CD PROFILES.
We highly recommend
that you calibrate your imaging system. This will assure you
repeatable results when opening our scans, converting the files
for a specific use, and printing. |