The following is a step-by-step guide to calibrating a display for accurate softproofing in the Blackmagic/Veripress SoftProof application.
The process described applies to calibrations for any SoftProof and press standard, but for this guide Blackmagic will be used to calibrate and verify an Apple Cinema HD display to an ISO Newspaper press standard.
A Press ICC match profile and a Calcheck Chart (imported or created using Blackmagic/Veripress) for the press standard to be softproofed are required for display calibration and verification. A supported Spectrophotometer instrument capable of reading monitor displays is also required.
For this guide the following will be used:
- Press Match ICC Profile – ISOnewspaper26v4.icc, defining a common newspaper press standard.
- Calcheck Chart – Newspaper, a 72 patch verification chart created with Blackmagic from the ISOnewspaper26v4 ICC profile, including Δe (CIE2000) and ΔH tolerances.
- Spectrophotometer – x-rite i1 Pro 2.
If a Calcheck Chart based on the press standard to be softproofed is not already stored in your Blackmagic Workbench database, one will have to be created and saved.
The chart to be used for this example was created with 72 patches using the Generate Patches from ICC option in the toolbar of the Calcheck Chart datatype.
The following delta (Δ) tolerances were configured:
- Δe Type – Set to CIE2000, the recommended type for measuring colours on a monitor display.
- Δe Average – 3.00
- Δe Maximum – 6.00
- Std Deviation – 1.50
- Cyan, Magenta, Yellow and Black Δe Tolerances – 5.00
- Paper and gray Patch Δe Tolerances – 3.00
The ΔH tolerances are active, turned on using the Target checkbox and configured:
- Average – 1.50
- Maximum – 2.50
- Paper and Gray ΔH Tolerances – 1.50
Configuring the Press
The Press datatype is used to emulate the properties of a press for softproofing.
To create a Press:
- Select the Press datatype in the Workbench application.
- Select File > New to create a new Press and rename it to Newspaper (ISO 26v4).
- Assign the Press Match ICC profile to the press by clicking the Press ICC Profile button in the Colour Management panel of the Press.
- Select the ICC file ISOnewspaper26v4 from the popup chooser window and click OK.
Note: If the Press ICC profile you wish to use is not in the Blackmagic/Veripress ICC folders then select the Upload File option in the ICC chooser window. This will allow you to browse to your ICC file and load it into the database.
- Assign the Calcheck Chart to the Press by clicking the Calcheck Chart button in the Colour Management panel and selecting the chart – Newspaper – from the chooser. Click OK.
- Set the Paper Colour for the Press by selecting ICC Profile from the Paper Colour dropdown at the bottom of the Colour Management panel.
- Save the Press configuration via File > Save.
Setting the SoftProof Default Press
Now the Press configuration should be set as the Default Press in the SoftProof application. To do this:
- Open SoftProof via the Application menu > SoftProof option.
- Go to File menu > SoftProof Settings.
- Select the Default Press tab in the window.
- Click the ‘Press’ button. Select the Press – Newspaper (ISO 26v4) – in the chooser and click OK.
- Click OK in the SoftProof Settings window to save the Default Press settings.
- Close the SoftProof application.
Calibrating Your Display
To begin display calibration, first plug in a supported Spectrophotometer (eg. x-rite i1 Pro) and open the Displays application via the Application menu > Displays.
The Displays application will open on the Calibration summary tab (highlighted in white on the left-side function menu). This tab shows data about the attached monitors, including the monitor name and resolution (in dpi) if the information is provided by the operating system, as well as the monitor calibration status.
- Click on the monitor number button above each summary to identify each monitor (if in a multi-monitor) environment and determine which display is to be calibrated for proofing.
- Select the monitor (eg. Cinema HD) from the names listed under Calibration in the left-side function menu.
- Choose an instrument – X-rite i1 Pro 2 – from the dropdown list of compatible Spectrophotometers in the Instrument section.
- Choose a display type – LCD (Default).
- Choose which calibration method to use from the Options section:
- Use Hardware Calibration – When supported, this option uses the monitors own internal hardware as part of the calibration process, allowing the screen brightness to be adjusted automatically.
- Use Self Calibration – Available on some high-end graphics monitors. Uses the monitors own internal hardware and calibration routines for calibration.
- Use Software Calibration – Calibration is performed using the Displays application software. In this case the monitor brightness level will need to be adjusted manually using a Spectrophotometer and the Measure button in the Brightness section.
- In this case, ‘Use Hardware Calibration’ is selected as the Cinema HD display allows remote brightness adjustment.
- Set the desired display brightness in candela (cd/m2) or percentage (0-100%) in the Brightness section – 200.00 cd/m2
- Set the desired whitepoint for the display in kelvin (K) in the Whitepoint section – Native.
- Set the gamma correction for the display in the Gamma section – 2.2
Note: The most suitable Brightness, Whitepoint and Gamma settings to use will vary from display to display. Some manufacturers or dealers may suggest optimal settings for proofing, but if colour verification fails, the settings can be altered.
- Click the Calibrate button and follow the on screen instructions for your instrument to begin display calibration. The white panel at the bottom of the Displays window will show the progress of the calibration process.
- When calibration is complete a file chooser window will appear.
- Name the display ICC created and Save it in a folder of your choice, e.g. cinemaHD-200-native-2.2
- The ICC profile is automatically saved as your operating system default monitor profile.
Assigning the Monitor ICC profile in Blackmagic/Veripress System Settings
The ICC profile created and saved during the display calibration process needs to be assigned as the Monitor ICC Profile in the Serendipity Client Preferences.
- Open Preferences in the Serendipity Client menu (Mac OS X) or via the Application menu (Windows).
- Select the Colour Management tab. This tab details the ICC profiles and resolution for all monitors used by the Client.
- In the section relating to the proofing display, tick the Calcheck Managed and Native Profile options.
- When the Use Native Profile box is ticked, the Choose Monitor ICC Profile will be grayed out (non-editable), but should display the saved ICC profile as the assigned monitor profile.
- If Use Native Profile is already active in the Client Settings, the ICC profile should already be assigned.
Once the native ICC profile for the monitor has been assigned close the Client preferences.
Calchecking the Display
The final step is to use the Calcheck function of the Displays application to verify your calibrated proofing monitor can accurately represent the print gamut being softproofed.
- Open the Displays application and select Calcheck in the left-side function menu.
- Under SoftProof Calcheck Status check that the Default Press is selected in the Softproof field, that the correct Press – Newspaper (ISO 26v4) – and Calcheck Chart –Newspaper – are selected.
- Select the monitor – Cinema HD – beneath Calcheck in the function menu.
- Choose an instrument – X-Rite i1 Pro 2 – from the dropdown list of Spectrophotometers in the Instrument section.
- Choose the display type – LCD (default) – and select Middle Centre of Screen.
Note: Choosing to Calcheck only the middle centre is normal for most softproofing purposes. If you have a suitable high-end graphics monitor, you may wish to select the 3 x 3 grid option and calcheck all areas of the monitor.
- Click the Measure button. Choose the Calcheck Chart – Newspaper – from the popup and click OK.
- Follow the on screen instructions for your instrument to begin display calibration.
- When the Spectrophotometer has finished taking measurements the Calcheck Summary results will be displayed.
- To view details of individual patch measurements click the Details button (top right icon in the summary screen).
If the display passes a Calcheck as denoted by a green tick then it is now ready for colour accurate proofing.
The latest (current) Calcheck results are now viewable in the Calcheck summary. Previous Calcheck results can be viewed in summary via the History menu option and in detail by selecting the monitor name below “History”.
If the display fails Calcheck possible reasons include:
Brightness, Whitepoint or Gamma Settings
If a few of the Calcheck patches fail or the Δe / ΔH values are up near the edge of tolerances, it may be that all that’s required is to adjust the brightness, whitepoint and possibly the gamma settings of the display.
Calibrate the monitor again as per the guide above after adjusting the brightness and/or whitepoint of the monitor. Save and assign the created ICC profile and try calchecking again. Try higher and lower brightness and whitepoint until the monitor passes Calcheck. Note: A Gamma setting of 2.2 is almost always the correct setting for current monitors and graphic cards.
If the measured Calcheck results for any or all patches are marked different from the reference values, e.g., cyan Δe of 50.00, it is possible the Spectrophotometer has read the patches incorrectly or that it didn’t initialise properly.
Check the instrument is calibrated correctly at the start of the measuring process and that the Spectrophotometer is sitting flush with the monitor when measuring.
Display is not capable of reproducing the gamut defined in the Press ICC Profile
In this case you may find that while many patches pass Calcheck, some parts of the ICC gamut (patches) such as Cyan or Magenta will fail.
For e.g. Δe summary numbers that indicate the monitor may be appropriate to purpose might look like this:
- ΔCyan 12.70
- ΔMagenta 9.20
- ΔYellow 2.10
- ΔBlack 1.70
- ΔGray 2.00
- ΔPaper 1.20
Not all displays are capable of displaying the full gamut of a press (print) colourspace. While many monitos are able to reproduce a newspaper gamut, only higher-end graphic monitors can reproduce an ISO offset press gamut.