Preparation

1. Scan your Q-60 target at gamma 1.0. A 300 dpi scan is more than enough, even 150 dpi is good. Set the scanner driver to full manual with full range (0...255) and disable all "color-management" that there may be in the driver.

2. Download the corresponding Q-60 CGI simulation. They are in WideGamut, D50, gamma 1.0 -space so they must be converted into your color-space. Therefore verify that Profile Mismatch Handling in the Profile Setup is not set to ignore.

3. Open the Q-60 CGI simulation and allow Photoshop to convert it into your linear working space
   I recommend to use either the AIM RGB or AIM RGB Pro spaces. This example was done in the AIM RGB Pro working space (WideGamut, D65 and Gamma 1.0). However this calibration is possible in what ever linear working space.

Arrange the layer situation as shown on the right:

1. The Q-60 CGI is at the bottom, in accurately up-sampled size using the Nearest Neighbor method and aligned accurately with the scan.
   Note 1: Up-sampling and alignment is easiest to do using the FreeTransform command.
   Note 2: In order to have the FreeTransform to do the up-sampling using the Nearest neighbor method that mode has to be first activated in the Preferences.
   Note 3: optionally replace the white border with some dark gray value, (this helps visual adjustment by not adapting the eye to light white).
2. The linear scan (gamma 1.0) from your acquire device is on top of the Q-60 CGI and that scan is in layer mode: Difference.
3. Over the scan add a Curves adjustment layer that is grouped to the scan layer.
4. Finally add a levels adjustment layer at the top, not grouped. This is a helper only, scale the right input lever of RGB composite layer to say down to 64. This boosts the difference so it is easier to evaluate visually.

Achieve Gray Linearity

Open the Curves adjustment layer and using the individual R and G and B channels (do not touch at all to the composite RGB channel) adjust so that the column 16 as well as the horizontal gray wedge at the bottom of the Q-60 appear as black as possible.

On-screen appearance after Curves

Curves adjustment

Only pay attention to gray column 16 and to the horizontal gray swatch.

Use the Levels helper adjustment layer to see the difference more clearly.

Depending on the amount of noise at the black-end the black-point may need an adjustment that can be done with the gray linearity curves, in this example one level is cut.

Note: With some scanners the exposure error may be in such direction that the white end of one or more of the curves may want to locate somewhere on the top edge of the sp-line box, this can not be allowed since it will cut image detail from the highlight. Therefore in this case a levels adjustment layer has to be grouped with the Q-60 CGI simulation in order to scale it downwards that much that the curves will end to the right edge or to the 255,255 corner.

1. Set the ColorSampler option to 5x5 sampling
2. Enable the Q-60 layer only.
3. Add three ColorSamplers.
4. Enter the RGB values into Excel.
5. Enable the Scan layer with the grouped Curves layer.
6. Enter the three RGB values into Excel.
7. Move the sampler over red, green and blue.
8. Enable the Q-60 layer only.
9. Enter the RGB values into Excel.
10. Enable the Scan layer with the grouped Curves layer.
11. Enter the three RGB values into Excel.
12. Enter the ChannelMixer values from Excel to the ChannelMixer adjustment layer.

In case the "Scale w-p to level" in the Excel sheet show other than 255 then you need to add a Levels adjustment layer to the calibration on top of the ChannelMixer with right slider in the composite RGB input channel scaled to that level.

After the ChannelMixer is added it is possible that careful (very delicate) adjustments to the Curves adjustment layer may help to bring the composite difference image even more darker.

So, with the ChannelMixer adjustment layer enabled open the Curves adjustment layer and again try to bring the gray column 16 and the horizontal gray bar as black as possible but not over the expense of larger error in any hue-patches.

Calibration is now done. It is possible that a Hue/Saturation adjustment layer could improve the match still. However the Curves and ChannelMixer usually result a very good calibration and the Hue/Saturation of Photoshop may introduce color noise into the image.

The final calibration is demonstrated on the right. Slowly click between then calibrated and simulation in order to see the difference.

Download the actual Photoshop file (in a small size) in case you like to examine it closer. This calibration was created in the AIM RGB Pro working space, so it needs to be viewed in that space also, the profile is included in the zip archive.