HDR Headroom?

[sloan.d]

Pardon my ignorance, but is HDR headroom part of a camera's exif data and, if so, can the exiftool be used to modify the value. I'm asking because my camera's (EOS R5 Mark I) HDR PQ images are too dark when displayed on an HDR monitor on a computer running macOS Sequoia (15.1).

My theory is that the colour management software on the Mac sees the Canon images as much brighter than than they actually are and subsequently dims the brightness to accommodate the limitations of the HDR monitor.

Not surprisingly, HDR PQ files from an iPhone 15 Pro display beautifully with the same setup. I am hoping that I can adjust the HDR headroom so that Canon HDR PQ images look as good.

[StarGeek]

I don't have any knowledge on HDR stuff, so I can't answer you. But you should run the command in FAQ #3 on your file to see what might be there.

The only EXIF tag that mentions HDR is the CustomRendered tag. Take a look at the notes on that tag on the EXIF Tags page, as they are Apple specific.

Otherwise, any such information might be in the MakerNotes, listed as a Canon tag. Very few programs will actually read the MakerNotes, though, so if it is there, it is unlikely to affect the display.

[sloan.d]

Thanks for that information. I didn't find much related to HDR.

I found an article about HDR stating the following:

Tonemapping Content to a Display

When HDR content is rendered to a display, it is transformed by a tone mapping operation to produce an image that fits within the display's HDR headroom.

This information suggests that incorrect headroom for Canon HDR PQ images may be the cause of the issue that I observed.