Objective: At the completion of this module you will be
able to calibrate
(if possible) and profile
a flatbed scanner utilizing given hardware and software tools.
You might wonder
why you would need to or want to calibrate and profile your flatbed
or film scanner? Most photographers that work with digital images,
open and edit their images with Adobe Photoshop. In Photoshop the
image can be corrected and adjusted to obtain optimum brightness,
contrast, color balance, etc. so why bother calibrating and profiling
to color manage your scans is really a workflow issue. A properly
calibrated and profiled scanner will save you time and effort. For
example if you are scanning color positive images (slides) most
likely your slides are already properly exposed and color balanced,
if you simply want these images in digital form and do not need
to adjust them in Photoshop then you would certainly want to color
manage your scanner, this is assuming of course that your time is
valuable! The thought process here is that your input (original)
can and should closely match what you get out (output/scan). It
is much better from a workflow and image quality stand point to
obtain an optimally scanned image by utilizing a profile and ICC
color workflow than it is to scan an image without a profile and
make color and tonal adjustments in Photoshop after the fact. Why
not get it right from the beginning?
however that film negatives will benefit from calibrated but not
profiled scanners. The color information in a negative is the reverse
of what you want in a scan and it also contains an orange mask.
You cannot make custom profiles
for color negative films. You can however make
use of color negative lookup tables. These negative lookup tables
are similar to profiles in that they describe the color characteristics
of a particular film emulsion, IE: Kodak Portra 400, Fuji Velvia,
etc. and will help you obtain more accurate color from your color
There are quite
a variety of scanners and scanner manufacturers in the market today.
We are not going to discuss or go over all of the different options
available but do want to discuss film vs. reflective calibration
Many scanners both flatbed and film come with a calibration
target and software that will let you calibrate (bring to a known
value) your scanner. Often times the industry refers to this as
linearizing the device, which really is the same as calibrating
it. If this option is available to you, then by all means do it.
It is always a good idea to start from a known value or standard.
Regular calibration will also enable you utilize the same scanner
profile because you'll always have the ability to return the scanner
to it's original state.
used to calibrate and profile scanners are often times similar
or the same. Some devices and or profiling software applications
come with custom targets while others use popular targets
made by Kodak, Agfa, Fuji and others.
Kodak "IT8" target is a well known and often used
target. The manufacturers of these targets also provide reference
files (usually simple text files) that include the LAB
values for each color patch. These values serve as a reference
point for the color values attained when the target is scanned.
A point of comparison if you will, that is used to create
a calibrated state or generate a custom profile.
Eye-One Match software
sure the scanner has been on for at least 15-30 minutes so that
the lamp has stabilized before scanning.
your scanner if possible, this will be a built in routine and the
software will generally walk you through the process. The scanner
we are demonstrating here does not have a calibration routine.
Eye-One match software, select scanner as the device to profile.
the Eye-One spectrophotometer.
This spectrophotometer comes with a white plaque specifically
for calibrating it. The plaque is built into it's holder,
simply place the unit in its holder and select calibrate from
the software. Calibrating the device each time like this ensures
the scanner reference chart/target. The Eye-One application
comes with a scanner target. This target can be read by the
Eye-One spectrophotometer, this ensures very accurate reference
data for a more accurate scanner profile.
the scanner target one strip at a time with a plastic guide.
Take your time making these readings, if you go too fast you'll
receive an error.
measurement data. Save the target values. This file should
be saved to a folder so that it can be easily retrieved later
as a reference file.
the scanner target.
sure that the scanner glass is clean and dust free. It is
also critically important that the scanner is set to its default
settings. Turn off unsharp masking if available and make sure
that the scanning software does not embed a profile.
the scanned file as a "tiff", full size at no more
than 200 pixels per inch.
the scanned target file. Select the file you just scanned
the scanned target file so that it fits tight to the crop
lines in the software. Rotate the file if necessary to match
the sample image in the help window.
a quick check to make sure that the scanned chart looks like
the original measured chart. If it does not you've done something
wrong, back track and fix it.
software will now create a custom profile
for your scanner based on a comparison of the scanned target
file color values versus the measured target color values.
the new scanner profile. Give it a name that you can remember
and add the current date.
Use the new profile. In Adobe Photoshop you can assign the
new scanner profile to your image if you have not or could
not do so from the scanning software. Many scanners will let
you embed a scanner profile.
example I have opened the image in Adobe Photoshop and assigned
the scanner profile, to do so, go to the top menu in Photoshop
and select Image > Mode
> Assign Profile from the pull down menu.
Click on the Profile button and select your
scanner profile, click OK when finished.
the images color space to your working
space (Adobe 1998). You will most likely want to do some
work on your image in Photoshop. It is best to edit your image
in a larger color
gamut color space than that of your scanner. In this example
I have converted the image to Adobe 1998.
the image from the scanner profile to Adobe 1998 go to the
top menu in Photoshop again and select Image
> Mode > Convert to Profile.
You've reviewed the steps needed to profile your scanner. Before
you move onto the next module please complete the following review
questions. These questions will determine how well you remember
and understand this information. If you have trouble with these
questions you may want to take another look at this information
before moving on to module 3.
on the correct answer
1) You should
always embed a profile with the scanned target file.
2) If possible
you should calibrate your scanner after creating a profile for it.
3) You cannot
create a custom negative film profile for for your scanner.
4) The scanner
target reference file contains the numeric color data found in a
Good job, if
you did well on these questions your ready to move onto module 3....
"Profile your Printer".