Does HDR editing work with 13" M4 iPad Pro in sidecar mode?

[johannes_42]

Does the 13" M4 iPad Pro work as an HDR screen for the Develop module of Lightroom Classic when used in the sidecar mode with an Apple Silicon Mac (M1 Mac mini in my case) when the non-sidecar screen is an SDR screen (Studio Display in my case)?

If it works as an HDR screen, how many stops of HDR can it do? Does the iPad Pro have to be in Reference Mode?

[Jao vdL]

Last time I tried with my mini (which has HDR capable screen) it did not do HDR on the sidecar screen. That's a while ago so this might have changed and Apple might enable different modes for the iPad Pro. 

[johannes_42]

Was that with an M4 iPad Pro, specifically?

I suspect that if HDR works in sidecar at all, it probably requires the M4 iPad Pro to be in reference mode. Has anyone here tried that specifically?

[Rikk Flohr: Photography · Accepted solution]

I've tested an M4 iPad Pro in Reference Mode, and it does view HDRs correctly when used via Side Car. If you disable Reference mode, the image returns to SDR. 

[johannes_42]

Excellent. Thank you!

[Conrad_C]

Wow Rikk, that’s great to hear. Thanks for responding because probably not many people have tried this specific combination (Lightroom Classic, iPad Pro, Sidecar, Reference Mode, HDR).

I was interested in the answer too, because although I have an iPad Pro, it’s the generation before Apple upgraded that display to HDR with Reference Mode so I couldn’t test it.

[johannes_42]

I have now have a 13-inch iPad Pro (M4), so a couple of additional details:

1. In the Reference Mode, the screen brightness of the iPad Pro cannot be adjusted (but the locked brightness works indoors, especially with room lights turned off)

2. The amount of display headroom reported by the histogram in Lightroom Classic is between 3 and 3.5 stops.

Notably, the spec sheet nits of the OLED display on iPad Pro and the mini-LED LCD on M4 MacBook Pro are the same, but when M4 MacBook Pro is _not_ in Reference Mode (I haven't tested MacBook Pro's Reference Mode; I was briefly testing someone else's MBP), its screen brightness can be adjusted such that Lightroom Classic's histogram reports 4 stops of display headroom.

Still, I find the 3-and-some stops of headroom with iPad Pro is enough for HDR editing whereas the 1 stop of headroom on the Studio Display is not.

[miric]

Which display mode do you use for the Sidecar iPad as a second display in Lightroom?

[miric]

Which view? Adobe Lightroom? Apple Photos works well, but not HDR editing in LrC.

[miric]

Has anyone been able to edit a RAW photo in the latest Lightroom Classic using a sidecar iPad Pro M4?

I connect the 11” iPad Pro M4 to my Mac mini via USB-C and use it as a Sidecar display in Reference Mode (Extended Display). I launch the latest Adobe Lightroom Classic and open a RAW photo for editing. I enable the second display with the options “Full Screen” and “Loupe - Normal.”

I can see the changes on both displays as I adjust the photo settings. However, HDR is not visible on the iPad. Google Chrome passes HDR tests from https://gregbenzphotography.com/hdr/, I can view HDR photos in Apple Photos opened on iPad display but it does not work with Lightroom.