TAKE CONTROL OF YOUR COLOUR...

To Start
Calibration Probe integration for the LightSpace CMS consists of a couple of additional options for the standard LightSpace program.

• Calibration Interface - for display set-up checking
• Profiling & profile Management - for display profiling and auto-LUT building

When started, the LightSpace CMS program will offer the chance to register. If the program has been purchased, and is not being used just for evaluation, follow the registration instructions.

For demo purposes, continue without registration, which will give 15 days usage, although many functions will be disabled, and the Calibration Interface Profiling options will display random data.

Registration details (and the option to register at a later date) are always available via the 'help' menu.

Calibration Interface
The Calibration Interface enables display devices to be checked and dynamically aligned while measuring the display output.

When the LightSpace CMS program has started, and a Calibration Probe has been connected, select 'Tools/Calibration/Calibration Interface' to open the Calibration option.

This will open the following window:

Follow the on-screen instruction to perform a dark calibration set-up, if required.

When the dark calibration is complete the main functions of the Calibration Interface can be used.

The first setting to be set is the target colour space to be measured using the above drop-down menu, which offers Rec709, P3-DCI-D55, P3-DCI-D65, and XYZ. If a different colour space is required it can be generated in the 'Convert Colour Space' menu, and saved for use elsewhere, and will appear in the dropdown Colour Space window above.

Next, the display colour for measuring can be set as required from the Colour drop-down menu. Clicking on the colour patch will launch a docked colour Calibration Area of the selected colour, that can be undocked and re-sized/positioned as required.

If measuring a monitor connected to a separate PC/Mac/Linux system on the same network as the LightSpace PC use the 'Calibration Client' to run a linked display window on the networked system (see below for info on the Calibration Client).

Next, the Probe Options can be set as required from the above menu. Select the required light measurement units; integration time (slower for dark level calibration); direct view for monitors, and projectors for, well, projectors. Average Low Light Measurements will help when measuring low luminance, as will longer integration times. And if necessary, another Dark Calibration set-up can be performed.

With the various settings set, measurements can now be taken via the 'Start' menu button for continuous reading, with the option to log the data as it is read in a csv format ready for display in an Excel spreadsheet.

With the continuous reading option it is then very easy to see via the graphical display where the target colour space is, and where the measured colour space presently is, and what needs to be adjusted to make them match... as with the Rec709 grey scale calibration below.

The cross shows in real-time where the colour space being measured actually is, and the circle shows where it should be.

And with primary colour points, as with Rec709 green below.

It is therefore very easy to adjust the monitor control to give the correct reading while looking at the Calibration Display in real-time.

There is also a real-time digital readout of the measured values.

And if 'logging' is enabled a csv formatted readout is available...

Network Connectivity
If calibrating a monitor connected to a PC/Mac/Linux system via a network connection select 'Network Manager' and 'Enable' it. If the Calibration Client has already been opened on any networked systems it will show the available systems.

To install the Calibration Client Java application on a separate system copy the application from the main software directory (usually: C:\Program Files\Light Illusion\LightSpace\Calibration Client). Copy this whole folder into a location within the networked PC, Mac or Linux, and make a link to the .bat file (changing the icon to the included .icon image).

On the networked system connect via the Calibration Client, and enter the IP address/PC name of the system LightSpace is hosted on.

If profiling a monitor connected to the PC LightSpace is installed on there is no need to activate the Network Client.

If a remote monitor cannot be controlled via the network client locally display patches of the correct value, using the values shown within the [square] brackets within the LightSpace Calibration Interface.

Display Characterisation
Display Characterisation enables any display device to be profiled, and the profile information to be used to automatically generate a LUT matching two profiles - such as a digital display to a film profile.

Note: Before profiling different displays the underlying display set-up MUST be performed using the 'Calibration Interface'.

Specifically brightness and contrast values need to be set as close to being matched as possible. Without this underlying display set-up being performed any profile measurement will be next to useless.

When the LightSpace CMS program has started, connect the probe, and select 'Tools/Calibration/Display Characterization' to open the profiling functions.

If this is the first time a probe has been connect since the software has been started, and if required, the option to Dark Calibrated the probe will be displayed. Follow the on-screen instructions.

Next, select 'Probe Options' and set the parameters as required, including Integration Time, Display type (direct view or projection), or to re-perform a Dark Calibration.

Note: it is best to leave 'Integration Time' to the pre-set 2 seconds duration.

When ready to profile, select the 'Measure' option and enter a unique name for the profile to be generated, and after re-checking probe alignment, and after making sure the monitor environment is dark (preferably a totally dark room) press 'Ready???' to begin profiling.

Remember that if profiling a display device on a network the Network Connectivity capability can be used.

Also, if profiling a display that cannot be connected to the LightSpace CMS PC directly (an SDI driven system for example) the software provides for the calibration flats to be exported as a dpx sequence of frames. These frames need to be made into a sequence of 3 seconds duration each.

When profiling is complete the profile will be saved in the 'Manage Colour Space' menu, and can be accessed via the 'Manage Colour Space' button.

To automatically build a LUT from the generated profiles select 'Convert Colour Space' from the 'Tools' menu, and select the profiles (colour spaces) to match to/from.

The above image shows a calibration LUT being generated to match a display to a film lab using Kodak 2393 print stock. The display was profiled using 4913 patched! Eeek indeed!!!

When the LUT has been generated the standard tools of LightSpace can then be used as necessary to modify the LUT. See the LightSpace CMS Manual for operational instructions.

As with everything to do with Light Illusion, Steve is more than happy to answer questions - feel free to contact him on: steve@lightillusion.com.