Calibrating an iMac Pro

Hi folks. I need your help with this one. iMac displays don’t come with built-in hardware RGB sliders, so direct adjustment of red, green, and blue channels isn’t possible on the hardware level. I’m using DisplayCal and an X-rite i1 Display Pro. When I google on how I can get the RGB to align, most of the answers is to set DisplayCal to “As measured” for RGB adjustments. This allows DisplayCal to calibrate through software adjustments rather than hardware adjustments. Okay, I got that. But where in DisplayCal can I adjust the RGB? If anyone has done this before, I really appreciate any help. Thanks.

It's a pre-adjustment you'd normally like to do to avoid bending the signal too much. Since it's not available in the iMac, let the calibration just do its job. You may need a more recent probe, though, according to this pretty knowledgeable guy. Citation: "Only Calibrite newest Display Pro HL and Display Plus HL are capable of profiling miniLED backlight displays such as Apple Liquid Retina XDR displays. All previous Calibrite / X-Rite devices are not capable of calibrating any miniLED backlight display including Apple Liquid Retina XDR inside the 14" & 16" MacBook Pro."
Here's the video:

Thanks Uli, as always. I don’t have the latest Apple display with the miniLED Liquid XDR. The iMac 5K, I believe is a mercury free LED backlight. So the xrite i1 probe is still good for it. I will check that video.

Ah, sorry, that was not obvious. Yes, you can calibrate that one quite well with an xrite i1. I have the same old Intel workhorse around too.

I’m using the prior version of the i1 Display Xrite Profiler software on the MacOS because DisplayCal is broken on Sonoma and the python3 alternative package of DisplayCal has issues. Still, it’s been confusing on how to adjust the white points on the MacOS. The new Calibrite Profiler software shown on the YT video is so different from the older version of Xrite Profiler. I downloaded the new version of Calibrite profiler but it doesn’t recognize the Xrite i1 display pro, saying it has an invalid SN and just terminates. Calibrite tech support is horrible as there is no way to reach a human, and there has been no response on the ticket I opened via their web support page to get some help with the latest Calibrite profiler software.

If anyone has a successful installation of DisplayCal (not the one from GitHub) from a package installation for MacOS Sonoma that doesn’t crash on startup and works, please share a link to where it can be downloaded. So far, the Python3 version on GitHub does install and work but it has been reported that some of the calibration algorithms may have bugs or incorrect calculations or recognizing the hardware calibration tool at times.

Ah, sorry, that was not obvious. Yes, you can calibrate that one quite well with an xrite i1. I have the same old Intel workhorse around too.

Do you set the display backlight to White LED or GB LED? I found that I get better results with GB LED on the 2017 IMac Pro and newer. Setting it to White LED produces a slight yellowish shift. After some readings, I learned that older iMac display (pre 2017) should use White LED settings and 2017 and newer should use GB LED. What’s your experience and method of calibrating your iMac?

Well, mine is not the Pro, so my results may not apply, but I got best results with White LED. Could it be that Apple changed panels during that year?

Well, mine is not the Pro, so my results may not apply, but I got best results with White LED. Could it be that Apple changed panels during that year?

Here’s something I found from X-rite on the Apple displays if this is interesting.
https://xritephoto.com/ph_product_overv ... rtID=5941#

Thanks, Ellory, for finding that. I may have to re-calibrate it now, even if I liked what I saw.
For final check, I got a calibrated screen via an I/O device anyway.