I'm struggling with the best way to edit HDR; I don't have an HDR timeline monitor. I use a FS5 and Atomos Shogun Inferno to shoot ProRes RAW, and edit with FCPX on an iMac Pro. I mainly produce for an LG HDR TV (at 700 nits). For workflow I adjust the clips within 700 nits, and without an HDR monitor really guess at the intermediate levels. My results so far are good but could really be improved.

In principle the Shogan Inferno can be used as a timeline monitor for FCPX but I have NOT been able to get the Inferno to respond (to my MacBook) as a monitor. Can anyone point me to a 'how to' article or YouTube for this?

I'd like to have a larger external timeline monitor, but have not located anything appropriate yet. I might pay quite a bit for this; I have several hours of spectacular Fiordland National Park NZ HDR clips to process.

It would be best to use a dedicated video card that can output SDI, that way you have no issues with the OS being in-between. For instance, a Blackmagic Decklink card would do.

Note that Atomos Shogun inferno is not fully HDR, it can output HDR luma wise but the color space is still limited. It's more like a "torch mode" monitor than a full HDR monitor.

https://www.blackmagicdesign.com/products/decklink

Perfect, thanks for the quick response.