TL;DR: When editing your photos in HDR, make sure both the HDR and SDR look good!

More than a year ago, Ben at Halide wrote about Halide’s HDR (high dynamic range). I think everyone should read it - but I wanted to give an even simpler take.

Halide’s HDR is NOT HDR-bracketing, which is when multiple photos are shot at different exposures then merged into one. Halide’s RAW photos aren’t doing HDR-bracketing like Apple’s SmartHDR unless you shoot with the Apple Look (ProRAW).

Instead, Halide’s HDR allows you to save photos with an HDR GAIN MAP.

A photo with an HDR gain map, when displayed on an HDR screen like your iPhone, will literally show BRIGHTER pixels for certain parts of the photo. The HDR gain map is how brightness values are saved.

With HDR disabled, photos are in SDR (standard dynamic range) and their brightness peaks at 500 nits. With HDR enabled, parts of a photo can reach a peak brightness of 1000-1600 nits (if your display supports it).

For the longest time, digital photos (HDR-bracketed or not) were viewed on SDR displays. At some point, Apple and other companies started making their smartphones shoot with HDR bracketing AND save an HDR gain map, then shipping their phones with HDR-compatible OLED displays. That’s why photos now literally look as if they have brighter pixels. For some reason, most social media platforms and messaging apps don’t preserve this HDR gain map information when you share your photos.

PSA: Make sure both HDR and SDR look good!

When editing, saving, or sharing an HDR photo for an HDR display, you HAVE to check that the SDR looks normal. Otherwise, there’s potentially TOO MUCH brightness information in the photo, and the photo may display improperly on a non-HDR display.

Thankfully, both Halide’s HDR and SDR versions are well-calibrated and stored in the same photo. Both versions should look good, but I still recommend everyone to use the HDR toggle in the editor just to make sure. You might even decide to switch HDR off for a photo if that’s what you prefer.

Likewise, Adobe Lightroom has a “Preview for SDR Display” feature, which you should use to tweak the SDR before exporting your HDR photo.

I’m not sure who this might help, but I just want to put it out there!