Today’s Question: When I click the HDR option in the Basic section for Develop in Lightroom Classic, why does it always overexpose the whites?
Tim’s Quick Answer: The issue you’re describing is a matter of how the image is being presented, and your experience suggests you are not using an HDR display to view and edit the image.
More Detail: The HDR button in the Basic section of the right panel in the Develop module in Lightroom Classic enables you to switch to HDR editing mode. As the name implies, this mode is for HDR image, but is also best employed when you have an HDR-capable display.
When you click the HDR button the image will be displayed in HDR mode, which among other things includes a histogram with sections for SDR (standard dynamic range) and HDR (high dynamic range). If you’re seeing blown highlights in the image as soon as you switch to HDR mode that generally suggests that there is some image data that extends beyond the SDR tonal range and that your monitor does not support HDR.
Only a limited number of monitor displays support HDR, and printers do not support HDR. Therefore, there are limited options for sharing HDR images with others unless they have been tone-mapped to SDR (standard dynamic range).
The HDR editing mode enables you to exercise greater flexibility and control over true HDR images, but is mostly only useful if you have an HDR-capable display. Even then, you most likely want the final image to be shared as SDR so it can be printed or properly viewed on monitors that do not support HDR.
You’ll notice, for example, that the histogram showing both SDR and HDR ranges shows data in the HDR section, which can’t be viewed on a non-HDR display. You would therefore want to either not work in HDR mode at all, or work in HDR mode but optimize the image so the tonal values do not extend into the HDR range based on the histogram.
Ultimately, I consider the HDR editing mode to be a bit of a niche feature that is mostly applicable only to photographers who are passionate about creating HDR images and also have an HDR-capable display for viewing the image data.
You can learn more about the HDR editing mode on the Adobe website here:
https://helpx.adobe.com/lightroom-classic/desktop/process-and-develop-photos/hdr-output.html
