NEC PA302W-BK-SV, PA272W-SV, PA272W-BK-SV, PA231W-BK-SV, PA302W-SV Troubleshooting
Version
1.1.04
User’s Guide
2 | SPECTRAVIEW II - USER’S GUIDE
Software Updates and Feedback
Occasionally updates and enhancements to the SpectraView software will be made available. Visit the SpectraView
II section of the NEC DISPLAY SOLUTIONS Internet web site to check for availability.
NEC DISPLAY SOLUTIONS welcomes feedback and suggestions for product improvements. Please use the
feedback from on the SpectraView section of the NEC DISPLAY SOLUTIONS Internet web site.
Within Australia and New Zealand, please visit the NEC Australia web site, www.spectraview.nec.com.au.
Technical Support
For technical support with the SpectraView II product, please visit the SpectraView II section of the NEC DISPLAY
SOLUTIONS Internet web site and check for any Frequently Asked Questions that may help to solve the issue. An
online feedback form is available for submitting questions and feedback.
For technical Support within Australia and New Zealand, please visit the NEC Australia web site, www.spectraview.
nec.com.au, or by email to spectraview.support@nec.com.au. Sales support Tel : 131 632.
Trademarks and Copyright
SpectraView is a registered trademark of NEC Display Solutions of America, Inc.
Adobe, the Adobe logo, Acrobat and Photoshop, are either registered trademarks or trademarks of Adobe Systems
Incorporated in the United States and/or other countries.
Apple, Macintosh, ColorSync, Mac and the Mac logo are trademarks of Apple Computer, Inc., registered in the U.S.
and other countries.
Microsoft, Excel and Windows are either registered trademarks or trademarks of Microsoft Corporation in the United
States and/or other countries.
Copyright © 2003-10 NEC Display Solutions, Ltd.
The content of this manual is furnished for informational use only, is subject to change without notice, and should
not be construed as a commitment by NEC Display Solutions, Ltd. NEC Display Solutions, Ltd. assumes no
responsibility or liability for any errors or inaccuracies that may appear in this manual.
All rights reserved. Your rights of ownership are subject to the limitations and restrictions imposed by the copyright
laws as outlined below.
It is against the law to copy, reproduce or transmit, including without limitation electronic transmission over any
network, any part of the manual except as permitted by the Copyright Act of the United States, Title 17, United
States Code. Under the law, copying includes translation into another language or format.
The above is not an inclusive statement of the restrictions imposed on you under the Copyright Act.
For a complete statement of the restrictions imposed on you under the copyright laws of the United States of
America, see Title 17, United States Code.
USA and Canada: www.necdisplay.com
Australia: www.spectraview.nec.com.au
Revision 100414
3 | SPECTRAVIEW II - USER’S GUIDE
HARDWARE LIMITED WARRANTY
NEC DISPLAY SOLUTIONS warrants the SpectraView II Hardware (hereinafter “Product” or “Products”) to be
free from defects in material and workmanship and, subject to the conditions set forth below, agrees to repair or
replace (at NEC DISPLAY SOLUTIONS’s sole option) any part of the enclosed unit which proves defective for a
period of three (3) years from the date of rst consumer purchase. Spare parts are warranted for ninety (90) days.
Replacement parts or unit may be new or refurbished and will meet specications of the original parts or unit.
This warranty gives you specic legal rights and you may also have other rights, which vary from state to state. This
warranty is limited to the original purchaser of the Product and is not transferable. This warranty covers only NEC
DISPLAY SOLUTIONS-supplied components. Service required as a result of third party components is not covered
under this warranty. Service required as a result of abuse or improper usage is also not covered under this warranty.
In order to be covered under this warranty, the Product must have been purchased in the U.S.A. or Canada by
the original purchaser. This warranty only covers Product distribution in the U.S.A. or Canada by NEC DISPLAY
SOLUTIONS No warranty service is provided outside of the U.S.A. or Canada. Proof of Purchase will be required
by NEC DISPLAY SOLUTIONS to substantiate date of purchase. Such proof of purchase must be an original bill of
sale or receipt containing name and address of seller, purchaser, and the serial number of the product.
NEC DISPLAY SOLUTIONS SHALL NOT BE LIABLE FOR DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL,
OR OTHER TYPES OF DAMAGES RESULTING FROM THE USE OF ANY NEC DISPLAY SOLUTIONS
PRODUCT OTHER THAN THE LIABILITY STATED ABOVE. THESE WARRANTIES ARE IN LIEU OF ALL OTHER
WARRANTIES EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. SOME STATES DO NOT ALLOW THE
EXCLUSION OF IMPLIED WARRANTIES OR THE LIMITATION OR EXCLUSION OF LIABILITY FOR INCIDENTAL
OR CONSEQUENTIAL DAMAGES SO THE ABOVE EXCLUSIONS OR LIMITATIONS MAY NOT APPLY TO
YOU.
This Product is warranted in accordance with the terms of this limited warranty. Consumers are cautioned that
Product performance is affected by system conguration, software, the application, customer data, and operator
control of the system, among other factors. While NEC DISPLAY SOLUTIONS Products are considered to be
compatible with many systems, specic functional implementation by the customers of the Product may vary.
Therefore, suitability of a Product for a specic purpose or application must be determined by consumer and is not
warranted by NEC DISPLAY SOLUTIONS.
Federal Communications Commission (FCC) Notice (U.S. Only)
WARNING: This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant
to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference
in a residential installation. This equipment generates, uses, and can radiate radio frequency energy and, if not
installed and used in accordance with the instructions, may cause harmful interference to radio communications.
However, there is no guarantee that interference will not occur in a particular installation. If this equipment does
cause harmful interference to radio or television reception, which can be determined by turning the equipment off
and on, the user is encouraged to try to correct the interference by one or more of the following measures:
Reorient or relocate receiving antenna.
•
Increase the separation between the equipment and receiver.
•
Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.
•
Consult the dealer or an experienced radio/TV technician for help.
•
This device complies with Part 15 of the FCC rules. Operation is subject to the following two conditions:
This device may not cause harmful interference.
•
This device must accept any interference received including interference that may cause undesired
•
operation.
SPECTRAVIEW II - USER’S GUIDE | 4
Contents
Precautions: . . . . . . . . . . . . . . . . 6
Supported Display Monitors . . . . . . . . . . . 7
System Requirements . . . . . . . . . . . . . 8
1 Introduction to SpectraView II 9
Overview . . . . . . . . . . . . . . . . . . 9
Main Features and benets . . . . . . . . . . 9
2 Dialogs, Settings and Menus 11
Main SpectraView II window . . . . . . . . . . 11
Display Conguration dialog (Windows version only) . 13
Edit Calibration Target Conguration dialog . . . . 14
Custom Gamma Curve dialog . . . . . . . . . 16
Custom White Point dialog . . . . . . . . . . . 17
Preferences dialog . . . . . . . . . . . . . . 18
Preferences dialog - Calibration Sensor tab . . . . 18
Preferences dialog - Calibration tab . . . . . . . 19
Preferences dialog - ICC Prole tab . . . . . . . 20
Preferences dialog - Interface tab . . . . . . . . 21
Preferences dialog - Display tab . . . . . . . . . 22
Information window. . . . . . . . . . . . . . 23
Information window - Summary tab . . . . . . . 23
Information window - Color Gamut tab . . . . . . 25
Information window - Curves tab . . . . . . . . 26
Information window - Color Tracking tab . . . . . 27
Information window - DICOM Conformance tab . . . 28
Colorimeter window . . . . . . . . . . . . . 30
Ambient Light Measurement window . . . . . . . 31
Monitor Settings window. . . . . . . . . . . . 32
Menus . . . . . . . . . . . . . . . . . . . 33
File menu . . . . . . . . . . . . . . . . . 33
Edit menu . . . . . . . . . . . . . . . . . 33
Tools menu . . . . . . . . . . . . . . . . . 33
Help menu . . . . . . . . . . . . . . . . . 33
Introduction to display monitor calibration . . . . . 34
3 Calibration Overview 34
About Targets . . . . . . . . . . . . . . . . 36
Gamma and Tone Response Curves (TRC) . . . . 36
White Point . . . . . . . . . . . . . . . . . 36
Intensity . . . . . . . . . . . . . . . . . . 37
4 Using SpectraView 38
Launching. . . . . . . . . . . . . . . . . . 38
Selecting a calibration Target . . . . . . . . . . 38
Modifying Targets . . . . . . . . . . . . . . . 38
Calibrating and Proling the Display . . . . . . . 39
Proling the Display . . . . . . . . . . . . . . 39
Validating the current Calibration . . . . . . . . 39
5 Outside of SpectraView 40
Using ICC/ColorSync Monitor Proles . . . . . . . 40
Adobe Photoshop Overview . . . . . . . . . . . 40
6 Frequently Asked Questions 41
Calibration . . . . . . . . . . . . . . . . . 41
7 Troubleshooting 43
Installation and Setup . . . . . . . . . . . . . 43
Using SpectraView with NaViSet Administrator . . . 45
8 NaViSet Administrator 45
9 Test Pattern Guide 46
10 MultiSync PA Series Information 47
Glossary 48
6 | SPECTRAVIEW II - USER’S GUIDE
Precautions:
The LCD display monitor screen is fragile and can be easily damaged if force is applied. Never
•
use suction cups to attach a color sensor to the display. Always use the supplied cable or sling and
counterweight to gently rest the color sensor on the face of the display.
During the display calibration procedure, highly sensitive light measurements are made on the
•
screen using the color sensor. High ambient light levels such as direct sunlight on the screen, may
affect measurements and cause an inaccurate display calibration. Changes in ambient lighting can
alter how images on the screen are perceived. Locate the display away from bright direct lighting
whenever possible and keep a constant ambient lighting level.
Always store the color sensor in the holder when not in use.
•
Never touch the measurement window in the color sensor.
•
Never disconnect the color sensor while the SpectraView software is running.
•
Always allow the display to warm up for at least 30 minutes before calibrating.
•
Do not adjust the monitor color, brightness or contrast controls once it has been calibrated,
•
otherwise the color calibration of the monitor may become invalid.
( Mac OS only) Do not use the ColorSync control panel to switch between different display
•
monitor calibrations by selecting different monitor color proles. Always use the SpectraView
application to load a previous monitor calibration. This is because all of the necessary color
adjustments, including the Look Up Tables, are stored in the display monitor and these must be set
by SpectraView. The ColorSync proles generated by SpectraView contain linear Look Up Tables for
the video graphics adapter.
Note:
This document covers both the Mac OS and Windows versions of the SpectraView II software. The features
and functions of both versions are identical unless noted otherwise. The majority of the User Interface
screen images in this document show the Mac OS version, however the Windows version is identical in
layout unless noted otherwise.
7 | SPECTRAVIEW II - USER’S GUIDE
Supported Display Monitors
SpectraView II supports the following NEC display monitor models:
LCD1980SXi – 19” LCD monitor
•
LCD1980FXi – 19” LCD monitor
•
LCD1990SX – 19” LCD monitor
•
LCD1990SXi – 19” LCD monitor
•
LCD1990SXp – 19” LCD monitor
•
LCD2090UXi – 20” LCD monitor
•
LCD2180UX – 21” LCD monitor
•
LCD2180WG-LED – 21” LED wide color gamut LCD monitor
•
LCD2190UXi – 21” LCD monitor
•
LCD2190UXp – 21” LCD monitor
•
LCD2490WUXi – 24” LCD monitor
•
LCD2490WUXi2 – 24” LCD monitor
•
LCD2690WUXi – 26” wide color gamut LCD monitor
•
LCD2690WUXi2 – 26” wide color gamut LCD monitor
•
LCD3090WQXi – 30” wide color gamut LCD monitor
•
LCD4020 – 40” LCD monitor
•
LCD4620 – 46” LCD monitor
•
LCD5220 – 52” LCD monitor
•
LCD6520 – 65” LCD monitor
•
M40, M40B, and M40-2 – 40” LCD monitors
•
M46, M46B, and M46-2 – 46” LCD monitors
•
X461UN – 46” LCD monitor
•
X461HB – 46” LCD monitor
•
P401 – 40” LCD monitor
•
P461 – 46” LCD monitor
•
P521 – 52” LCD monitor
•
P701 – 70” LCD monitor
•
P221W – 22” wide color gamut LCD monitor
•
PA241W – 24” wide color gamut LCD monitor
•
PA271W – 27” wide color gamut LCD monitor
•
8 | SPECTRAVIEW II - USER’S GUIDE
System Requirements
SpectraView has the following system requirements:
Mac OS
Operating System Apple Mac OS X v10.3.9 or higher.
Mac OS 10.5.2 or higher required for
some Mac models. See README le
for details.
ÿ
Microsoft Windows
Microsoft Windows 2000, XP, XP x64,
Server 2003, Vista and Vista x64, Windows
7 and Windows 7 x64.
Video Graphics Adapter All Apple standard video graphics
cards, including most newer
PowerBooks. Digital (DVI) output is
highly recommended.
See the README le and NEC website
for the latest information on Macs with
DisplayPort video output.
Video Color Depth At least 24 bit color (Millions of colors). At least 24 bit color.
Video Resolution Displays native resolution highly
recommended (1280x1024, 1600x1200,
1680x1050, 1920x1080, 1920x1200,
2560x1440 or 2560x1600 depending
on monitor)
Supported Color
Sensors
USB At least one available USB port for
GretagMacbeth Eye-One Display V1
•
X-Rite/GretagMacbeth Eye-One Display
•
V2
X-Rite/GretagMacbeth Eye-One Monitor,
•
Eye-One Pro.
X-Rite ColorMunki.
•
Monaco OptixXR (X-Rite DTP 94).
•
ColorVision/Datacolor Spyder 2.
•
Datacolor Spyder 3.
•
Color Sensor.
Most recent ATI, Nvidia, Matrox, S3
Graphics, and Intel graphics adapters.
Digital (DVI) output is highly recommended.
See README le for details.
Displays native resolution highly
recommended (1280x1024, 1600x1200,
1680x1050, 1920x1080, 1920x1200,
2560x1440 or 2560x1600 depending on
monitor)
GretagMacbeth Eye-One Display V1
•
X-Rite/GretagMacbeth Eye-One Display V2
•
X-Rite/GretagMacbeth Eye-One Monitor,
•
Eye-One Pro.
X-Rite ColorMunki.
•
Monaco OptixXR (X-Rite DTP 94).
•
ColorVision/Datacolor Spyder 2.
•
Datacolor Spyder 3.
•
At least one available USB port for Color
Sensor.
9 | SPECTRAVIEW II - USER’S GUIDE
Introduction to SpectraView II
1
Overview
Designed for professionals with color critical applications, SpectraView II combines the award winning NEC display
monitor technology with a color measurement sensor and sophisticated software. The result is highly accurate,
reliable, repeatable, and feature rich display calibration and proling solution.
The SpectraView system uses a color sensor to take color measurements of the display screen during calibration.
The software analyzes these measurements and sends color adjustment commands directly to the display monitor.
This means that color adjustments are made in the monitor rather than in the video graphics adapter, resulting in
full use of the number of colors available on the graphics adapter and a much brighter image with the maximum
possible color gamut. With SpectraView, the video graphics adapter is not used at all to make any gamma or Tone
Response Curve corrections to the display, so the full color resolution and delity of the system is maintained.
Main Features and benets
SpectraView provides the following features and benets:
Automatic calibration - SpectraView communicates with the display monitors using Display Data
•
Channel - Command Interface (DDC/CI) which is a two-way communications link between the video
graphics adapter and display monitor using the normal video signal cable. No extra cables are necessary. All
adjustments to the monitor settings are done automatically using this communications link. It is not necessary
to manually congure the monitor as all of the necessary settings are made by the software.
High bit depth internal Look Up Tables (LUTs) - each LCD display monitor supported by SpectraView
•
II features three internal 10, 12 or 14 bit LUTs (depending on the model). These tables allow very precise
adjustments to be made to the display’s Tone Response Curve without reducing the number of displayable
colors or introducing color banding artifacts.
Multiple Calibration Sets - Different display monitor calibrations can be instantly loaded allowing quick
•
and easy switching between different calibration settings without the need to re-calibrate the display. Each
time a calibration set is loaded, the necessary monitor settings and ICC/ColorSync proles are automatically
updated.
Informative - At the end of each display monitor calibration, an information window is displayed which
•
shows the results of the calibration and includes a wealth of information about the display such as the
measured color gamut, grayscale color tracking, Delta-E, and luminance values. Additional information about
the display monitor such as the model name, serial number and the total number of hours that it has been in
use are also displayed.
Calibration status validation - SpectraView will query each calibrated monitor to see if any controls
•
have changed since the last calibration. If anything has changed, the previous calibrated state can be
restored automatically.
Flexible - SpectraView provides many features and options that make it exible enough to be used in a
•
large variety of applications, including full DICOM support for medical imaging. The display luminance can be
adjusted to either a specic value or to the maximum possible that the display can achieve.
Network support (ÿWindows only) - SpectraView integrates with the NEC NaViSet Administrator
•
network software (available separately from your NEC representative.) to provide remote network access
and monitoring of display monitors. NaViSet Administrator is able to read, display, and log the current
10 | SPECTRAVIEW II - USER’S GUIDE
calibration settings and status of displays on a LAN. This feature is particularly useful for large installations
where central monitoring and asset management is needed.
Monitor locking - Once calibrated the OSD (On Screen Display) controls for the display monitors can
•
be locked to prevent accidental or unauthorized adjustment which may invalidate the calibrated state of the
monitor.
Monitor Proling - After calibration, the display is automatically proled and highly accurate ICC/
•
ColorSync color proles are generated and automatically registered with the Color Management System.
These proles use the Bradford Chromaticity Adaptation matrix.
Colorimeter function - The software features a Colorimeter function which allows direct measurements
•
to be taken by the color sensor and the results displayed in a variety of different formats.
Ambient Light Measurement function - Allows measurements to be taken of the ambient light of the
•
viewing environment surrounding the display monitor. This is useful in determining the optimal viewing
conditions for the display monitor so that the ambient light level and color do not inuence the viewing of
images on the screen.
11 | SPECTRAVIEW II - USER’S GUIDE
Dialogs, Settings and Menus
2
Main SpectraView II window
The SpectraView II window shows the current settings and status of the display calibration. All of the features of
SpectraView are accessed from this window and the menus.
Edit Target
Opens the Calibration Target
Conguration dialog box used to
modify Target settings.
Open Target
Opens a Calibration Target
Targets listbox
Selects an existing
Target setting.
Targets that have
been calibrated have
green check mark.
le.
Save Target
Saves the current Target
Settings to a Calibration Target
le.
Calibration On
Turns the display
calibration on or off.
Calibrate
Calibrates the currently
selected display to the
currently selected Target
Settings.
Display listbox
Selects which display to
calibrate if more than one
display is present.
Open Previous Monitor
Calibration
Previous calibrations can
be loaded and viewed.
The display settings and
ICC/ColorSync prole
for the display will be set
automatically.
12 | SPECTRAVIEW II - USER’S GUIDE
Target Settings
The Target Settings group shows the current calibration Target parameters for the currently selected display
monitor. The Target Settings can be modied, saved and loaded using the Edit, Open and Save buttons.
The Target listbox shows all of the available Targets. When the display has been calibrated to a particular
Target, a green check mark appears next to the Target name, indicating that the calibration is available. Different
calibrations can be automatically restored by selecting different Targets that have been calibrated. This makes
it easy to quickly change between different calibrated Target settings. The green check mark will change to
yellow once the calibration for that Target has passed the recommended recalibration time, indicating it is time
to recalibrate that particular Target.
White Point shows the Target White Point.
Gamma shows the Target gamma or Tone Response Curve type.
Intensity shows the Target display intensity value.
Contrast Ratio shows the Target contrast ratio.
Calibration
The Calibration group shows the current calibration status of the currently selected display monitor and is
where the monitor calibration process is started.
The display monitor can be calibrated to the current Target Settings by clicking the Calibrate button. Note that
this Calibrate button will be disabled if either no supported color sensor or display monitor was detected. See
the Troubleshooting section for more information.
Status shows the current calibration status of the display monitor, either Calibrated, Uncalibrated, or
Calibration Off.
Last shows the date and time that the display monitor was last calibrated.
Next Due shows the number of days until the display is next due for recalibration, or the number of days past
when it was last due for recalibration. This is based on the date of last calibration, and the Recalibration
Reminder Period in the Preferences dialog.
If the display is not currently in a calibrated state the Calibration On checkbox will be unchecked. If the monitor
OSD controls are locked using the Lock OSD Controls option in the Preferences dialog, the OSD controls
will be automatically unlocked when the Calibration On checkbox is cleared. Selecting the checkbox will
automatically re-congure the display monitor to its previously calibrated state.
The Open button will open the Previous Monitor Calibration dialog which shows all of the previous calibrations
that have been performed. It is possible to view the detailed results of each calibration, as well as manually
selecting a previous calibration to load. Loading a previous Monitor Calibration will automatically congure the
display and re-generate the ICC/ColorSync prole, if one was generated when the calibration was performed.
This feature can be used to manually switch between different monitor calibrations with different Target settings,
or to restore a particular calibration.
Note: The Monitor Calibrations are specic to each individual display monitor and can not be used to load the
calibrated settings of one display monitor into another, even if they are the same model. This is because of the
individual tolerances and characteristics of each display monitor.
Display
The Display group is used to select the display monitor to calibrate if more than one display is present on
the system. Displays can be selected from the listbox and the Target Settings and Calibration status will be
automatically updated. Note that Target Settings are independent for each monitor when multiple monitors are
used, so each display monitor can be calibrated to different Target settings if desired.
13 | SPECTRAVIEW II - USER’S GUIDE
Display Conguration button (ÿ Windows version only) opens
the Display Conguration dialog which is used to congure
SpectraView II if more than one display is used on the system.
See the following section.
Display Conguration dialog ( ÿ Windows version only)
This Display Conguration dialog is accessed either from
the Edit menu, or by clicking on the Display: Congure
button in the main SpectraView window.
If more than one display is being used on Windows, it
may be necessary to manually congure the relationship
between the display layout on the Windows desktop, and
the display monitors that are connected to the system.
Correct conguration of this relationship is necessary
so that the display monitor adjustments are sent to the
correct monitor, and that the calibration is performed on
the correct part of the desktop.
A diagram depicting the display desktop layout is shown
and the display monitors associated with each desktop
screen is shown. The monitor associated with each
display can be selected using the listboxes.
Clicking on the display rectangles will also select different
displays on the Windows desktop.
Note: Some video graphics adapters may show several
duplicate displays due to issues with the video drivers for
that adapter. In this case the duplicate displays can be
selected to “None”.
Auto Congure - Attempts to automatically detect and
congure the display monitors to the display layout on
the Windows desktop. In most cases this will correctly
congure the correct relationship, but in some cases it
may be necessary to manually congure.
Test LUT - Tests that the video graphics adapter card LUT
(Look Up Table) can be correctly set. Clicking this button
with ash the screen brightness by setting the LUT in the
video graphics adapter card for the currently selected
display. Verify that the correct screen ashes when this
button is clicked.
Note: Since SpectraView applies all correction curves to the 10 or 12 bit LUT inside the monitor, the video
graphics adapter card LUT is always set to linear.
Test Monitor - Tests the communications with the currently selected display monitor. Clicking this button will
send a command to ash the monitor’s screen brightness. If the wrong display monitor ashes then change
the monitor associated with each display can be selected using the listboxes.
14 | SPECTRAVIEW II - USER’S GUIDE
Edit Calibration Target Conguration dialog
The Edit Edit Calibration Target dialog is accessed by clicking the Edit Target button on the main SpectraView
II window, or by selecting Target from the Edit menu. Custom Targets can be created using this dialog. After a
new Target has been created, the display must be Calibrated to it. It is possible to share Target les with other
users of SpectraView on both Windows and Mac OS platforms.
White Point
White Point selects the Target white point for the calibration.
Several popular industry standard White Point values, such as
D50 and D65, are provided.
A Native option is available that can be used to leave the White
Point at the display’s native characteristic white point. This is
useful when the maximum possible luminance is desired but
the white point is not critical.
A custom white point can be specied by clicking the Edit...
button to open up the Custom Color Temperature dialog.
Gamma Curve
Gamma Curve selects the desired tone response curve of the calibrated display. Options are:
Monitor Native Gamma - No correction is applied and the display’s Look Up Tables are set to linear.
•
Gamma Curve Value - The response curve will follow a simple gamma curve. Values between 1.0
•
and 3.0 can be entered. A gamma value of 2.2 is the most popular for most applications.
DICOM Curve - The response curve follows the DICOM (Digital Imaging and Communications in
•
Medicine) specication. This response curve is aimed at medical use, however it can be used for other
applications. The goal of the DICOM response curve is to have a visually linear display response.
15 | SPECTRAVIEW II - USER’S GUIDE
Use Scale Factor - The DICOM response curve shape is based on the measured black level and
Intensity. If the black level or Intensity of the display changes, then the shape of the DICOM response
curve also changes. If a display is not expected to be re-calibrated for a period of several months, this
feature can be used to increase the longevity of the DICOM calibration using the knowledge that the
displays brightness will decrease slightly as it ages. By scaling the black level and Intensity values
used to calculate the DICOM response curve, using the Use Scale Factor value, the response curve
can be based on the lower future black level and Intensity. The value used will depend on the display,
its usage, and the time interval until it is expected to next be re-calibrated.
Custom Curve - Advanced and custom response curves can be selected from presets or created by
•
importing a table of values. Click the Edit... button to open the Custom Gamma Curve dialog.
Intensity
The Intensity selects the luminance or “brightness” of white for the calibration. Options are:
Maximum possible - calibrates the display to the maximum possible luminance that it can achieve.
•
The actual value achieved will depend on the display’s type, its age and the white point used. This is
not recommended when trying to exactly match two or more displays, since there may be a difference
between what Intensity each display can achieve.
Specic Level - calibrates the display’s Intensity to a specied target value. If the display can not
•
achieve the specied value, it will be calibrated to the closest possible Intensity, and a message will be
displayed after the calibration has completed.
Note: If you are unsure about what level to use for the Specic Level for a particular application, it is possible
to interactively adjust both the White Point and Intensity using the Visual Match feature in the Custom White
Point dialog.
Contrast Ratio
Contrast Ratio allows a particular contrast ratio to be used if necessary. The contrast ratio is the ratio of white
to black luminance.
Selecting Monitor Default will calibrate the display to the
highest possible contrast ratio, which is limited by the display
technology, the selected White Point, Intensity value, and
other factors.
In some applications, such as simulating low contrast images
such as in newsprint, it is useful to have a lower contrast ratio
than the display’s native value. Contrast Ratios in the range
of 50:1 to 500:1 can be selected.
Note: If the selected contrast ratio is higher than what the
display is actually capable of achieving, then the display will
calibrate to the highest possible contrast ratio. If a specic
Contrast Ratio is selected, it is recommended that the
number of Calibration and Measurement Steps be set to at
least 32 in the Preferences dialog.
16 | SPECTRAVIEW II - USER’S GUIDE
Custom Gamma Curve dialog
The Custom Gamma Curve dialog is accessed by clicking the Edit.. button in the Gamma Curve section of
the Edit Calibration Target dialog.
Advanced response curves can be selected from presets or custom curves can be created by importing a table
of values.
The following preset curves are available:
sRGB - A curve based on the sRGB specication that includes the offset, transition and slope
•
components.
L* - A curve based on L* in the Lab specication. The L* curve is intended to be more perceptually
•
uniform than a simple gamma value curve.
NTSC Video - A curve based on the SMPTE-170M specication for NTSC that includes the offset,
•
transition and slope components.
SMPTE-240M - A curve based on the SMPTE-240M specication for 1125 line HD video that includes
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the offset, transition and slope components.
Custom curves can be created and imported into SpectraView by creating a text le with a list of numerical
values. The text le must conform to the following specications:
Must contain between 3 and 256 values.
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Each value must be on a separate line.
•
The rst value must be 0.
•
Values must be monotonically increasing.
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When imported, the values will be automatically scaled and interpolated to create a Target curve.
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