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Discussion Starter #1 (Edited)
I have written a short guide on how to perform a basic set of greyscale and colour measurements, using HCFR and ColourSpace ZRO. The reason for using one guide to describe both, is to show the mapping the corresponding operation between the two, which would be useful for users who are already familiar with one of the programs.

ZRO has comprehensive online Help and a dedicated thread:

This guide focuses on performing a specific task. This guide is also easier to use for those already familiar with HCFR.

The guide assumes you're using the X-Rite i1DisplayPro colorimeter, which is probably the most common meter used. ZRO natively supports the OEM version; if you have the retail version you need to contact them for an alternative DLL. The display type Projector is just an example; choose the type most appropriate for your display. The pattern generator is assumed to the the automatic generator, which is easiest for beginners.

For ZRO, any custom pattern sequence can be measured, using a csv file. I have attached the files for the 10-point greyscale and Primary/Secondary colours; simply rename the files to remove the txt file extension.

Note: the guide assumes that “range matching” the TV or projector is handled bythe PC’s graphic card based on the EDID of the display. This is the reason for setting the calibration software to 0-255, to avoid double scaling which will lead to incorrect patterns. Also note that ColourSpace (including ZRO) is not designed to use 16-235 patches.

Comments on the guide are welcome. Comments and questions on HCFR and ZRO themselves should be raised in the relevant threads.
 

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The same rule Dominic mentioned for the Retail I1D3 applies to the Munki when you're ready to try ZRO.
 

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Discussion Starter #9 (Edited)
This is very cool.

I have a ColorMunki. Any additional steps with a ColorMunki? I'll try this out with HCFR. (Can't try ZRO because even though I got in on the beta, I don't have a PC nor a working VM for my Mac at present.)
Which Colormunki? The Colormunki Display colorimeter should work just like the retail i1Display Pro. The other models (Photo, etc) are spectrophotometers and will require a driver to be loaded.
 

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Discussion Starter #10
Okay I'm stuck with HCFR for now due to software limitations.
Both HCFR and ZRO run on Windows (either native or virtual). There’s an old Mac version of HCFR but it only supports Spyder2, Spyder3, and the HCFR sensor.
 

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Both HCFR and ZRO run on Windows (either native or virtual). There’s an old Mac version of HCFR but it only supports Spyder2, Spyder3, and the HCFR sensor.
Urgh. I really have to get a windows laptop now that my VM software is again out of date.

Something like this would be as cheap as buying a new VM app and Windows license. Would it work fine?
 

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I have written a short guide on how to perform a basic set of greyscale and colour measurements, using HCFR and ColourSpace ZRO.

ZRO has comprehensive online Help, but this guide focuses on preforming a specific task. This guide is also easier to use for those already familiar with HCFR.

The guide assumes you're using the X-Rite i1DisplayPro colorimeter, which is probably the most common meter used. ZRO natively supports the OEM version; if you have the retail version you need to contact them for an alternative DLL. The display type Projector is just an example; choose the type most appropriate for your display. The pattern generator is assumed to the the automatic generator, which is easiest for beginners.

For ZRO, any custom pattern sequence can be measured, using a csv file. I have attached the files for the 10-point greyscale and Primary/Secondary colours; simply rename the files to remove the txt file extension.

Comments are welcome.
why 0-255 and not 16-235?
 

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Discussion Starter #15
why 0-255 and not 16-235?
When connected to a TV or projector, the graphics card will switch to 16-235 automatically based on the display EDID, so the software setting needs to be 0-255 to avoid double-scaling. In principle it would be more accurate to have the graphics card in 0-255 and the software on 16-235, but that’s more difficult to do.
 

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When connected to a TV or projector, the graphics card will switch to 16-235 automatically based on the display EDID, so the software setting needs to be 0-255 to avoid double-scaling. In principle it would be more accurate to have the graphics card in 0-255 and the software on 16-235, but that’s more difficult to do.
If you have the graphics card configured to rescale from 0-255 to 16-235 under the covers, and you haven't informed the calibration software of that fact, then all of the calibration targets computed by the calibration software will be incorrect for the patterns that are actually displayed. I don't see any such HCFR or ZRO setting being configured in your writeup. Does any calibration software even have an option to tell it that?
 

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Discussion Starter #17
If you have the graphics card configured to rescale from 0-255 to 16-235 under the covers, and you haven't informed the calibration software of that fact, then all of the calibration targets computed by the calibration software will be incorrect for the patterns that are actually displayed. I don't see any such HCFR or ZRO setting being configured in your writeup. Does any calibration software even have an option to tell it that?
The graphics card is not under the control of the calibration software, and needs to be configured independently by the user, who also needs to make sure the calibration software is configured accordingly. As explained previously, the rescaling should be done only at one place.
Almost all TVs and projectors default to 16-235, but of course it would be prudent to double#check that, if you’re uncertain. That’s the reason for setting the calibration software to 0-255.
I will add a note in the first post.
 

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The graphics card is not under the control of the calibration software, and needs to be configured independently by the user.
Yes, that's understood, what I meant is that if you don't tell the calibration software what the graphics card is doing, your calibration will be inaccurate, as the pattern actually displayed won't match the pattern that the calibration software thinks it's measuring. If that's not clear, I can provide an example.
 

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Discussion Starter #19
Yes, that's understood, what I meant is that if you don't tell the calibration software what the graphics card is doing, your calibration will be inaccurate, as the pattern actually displayed won't match the pattern that the calibration software thinks it's measuring. If that's not clear, I can provide an example.
You don’t directly “tell” the calibration software what the graphics card is doing; you simply set the pattern range accordingly. The guide assumes the graphics card is set to 16-235 (the default unless overridden), so the calibration software is set to 0-255. That’s all that’s needed.
 

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You don’t directly “tell” the calibration software what the graphics card is doing; you simply set the pattern range accordingly. The guide assumes the graphics card is set to 16-235 (the default unless overridden), so the calibration software is set to 0-255. That’s all that’s needed.
Here's a concrete example based on your settings, assuming Rec 709, 2.4 gamma, and a measured White of 100 nits. Your 60% gray, RGB triplet 153,153,153, within the 0-255 range, will have a target Y of 29.357 nits. Under the covers, the graphics card is rescaling that pattern to RGB triplet 147,147,147 (most likely) within the 16-235 range, so that's what's actually displayed and measured. That pattern would actually have a target Y of 29.133 nits, if you were to configure your calibration software for range 16-235 (and were using a pattern generator path that passed it unaltered to the display). So with 0-255 there's a mismatch between what the calibration software is calculating for targets, and the patterns that are actually being displayed and measured.
 
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