What Is HDR, Anyway?

Summary

It's not you. HDR confuses tons of people.Last year we announced HDR or "High Dynamic Range" photography was coming to our popular photography app, Halide. While most customers celebrated, some were confused, and others showed downright concern. That's because HDR can mean two different, but related, things.The first HDR is the "HDR mode" introduced to the iPhone camera in 2010.September, 2010The second HDR involves new screens that display more vibrant, detailed images. Shopped for a TV recently? No doubt you've seen stickers like this:This post finally explains what HDR actually means, the problems it presents, and three ways to solve them.What is Dynamic Range?Let's start with a real world problem. Before smart phones, it was impossible to capture great sunsets with point-and-shoot cameras. No matter how you fiddled with the dials, everything came out too bright or too dark.The result of trying to capture a sunset with an old-school camera.In that photo, the problem has to do with the different light levels coming from the sky and the buildings in shadow, the former emitting thousands of times more light than the latter. Our eyes can see both just fine. Cameras? They can deal with overall bright lighting, or overall dim lighting, but they struggled with scenes contain both really dark and really bright spots.Via WikipediaDynamic range simply means, "the difference between the darkest and brightest bits of a scene." For example, this foggy morning is an example of a low dynamic range scene, because everything is sort of gray.Screens have no trouble showing this low-contrast photo. Shot with Halide in Osaka.Most of our photos aren't as extreme as bright sunsets or foggy mornings. We'll just call those "standard dynamic range" or SDR scenes.Before we move on, we need to highlight that the HDR problem isn't limited to cameras. Even if you had a perfect camera that could match human vision, most screens cannot produce enough contrast to match the real world.Regardless...