If you've been irritated that you can't control when the official Windows 10 Mobile Camera app uses HDR (high-dynamic-range) for photos, some good news is headed your way. Microsoft imaging head Juha Alakarhu says the Camera app will soon get a "Force HDR" option, giving you the control you desire.
From All About Windows Phone:
After more than a few complaints around these parts of how Rich Capture works on the Lumia 950 and 950 XL, Microsoft's (ex-Nokia) imaging chief, Juha Alakarhu, has been in touch to let us know that 'Force HDR is coming' soon to Windows 10 Mobile's official Camera application, though he couldn't promise 'any dates yet'.
High-dynamic-range imaging is a technique that combines multiple images taken at a range of exposure levels in order to create a higher-quality, richer photo. Currently, the Windows 10 camera app automatically switches HDR on or off. There's no timeline yet for the introduction of this feature, but it's good to know it's on the way.
Source: All About Windows Phone