If you follow consumer technology news, you may have noticed increasing mentions of high dynamic range, or HDR. It's a technical term used to express a large range of luminosity in an image. Typically, HDR describes the quality of a photographic image. But it also describes video images--and with recent advancements in display technologies, HDR televisions and monitors are becoming a new confusing option for shoppers. Let's explore what this all means for you if you're in the market for a new display.
HDR for Still Images
When you take a picture with a smartphone, DSLR, or anything in between, the image is captured with fixed values for the shutter speed, ISO, exposure value, etc. In short, these all affect how much light the camera captures, and therefore how bright or dark the picture is.
If you're trying to take a picture of something with an extreme range of luminosity, you will find yourself with details being washed out in bright areas or lost in the shadows of dark areas. Imagine yourself indoors on a sunny day in a room with a large window. Or, looking at a person outside when the sun is behind them. The human eye is able to simultaneously see detail both inside and out, or the person's face despite the sun, but a camera taking a single image at fixed settings cannot.
It's these types of scenarios you want an HDR image. All high-end smartphones today can create one. Hit the toggle to turn it on, and now your phone magically takes pictures with a better dynamic range. Well, not quite. You've probably noticed that taking a picture on your phone with HDR turned on takes a bit longer. That's because it's actually taking multiple pictures: one overexposed, one underexposed, and one at a normal exposure, and then the camera software stitches them together for one great looking picture.
To make an HDR image from pictures taken with a DSLR it requires more steps. At the very least multiple images taken at different exposures are needed. Next you'll need image processing software. The most recent versions of both Photoshop and Lightroom from Adobe are capable of automatically creating HDR images. If you don't want to go through the process of manually putting them together with layers and the whole nine yards, you can use the merge to HDR feature and the software will automatically create an HDR image with what you've provided. Some DSLRs can do "in-camera HDR"; merge three bracketed images. However, they won't look as good compared to creating them with computer software.
No matter the device, or more specifically, the display, you're viewing an HDR image on you can see the benefits. This is thanks to a process called tone mapping. It's a technique used to bring down the dynamic range of an image or video, and can preserve most of the detail while allowing the content to be viewed properly on a standard dynamic range display.