![]() Once you open the camera app, it's running. Does it show 12345, making everything bright in the image look like a white blob? Or does is show 56789, making everything in shadow look like a black blob? Of course the answer is it will show 34567 or 45678, so some highlights are lost, and some shadow detail is lost, but the overall image at least looks something like what you shot.īetter cameras have better dynamic range: a mediocre phone camera might only be able to show 4567 while a great dSLR might be able to show 234567. Let's say the camera can show 5 of these numbers. They don't have the dynamic range of your eye. In other words, your eye can see 123456789 all at once.Ĭameras, though, can't. In real life, your eye could see both of those things at the same time, with minimal difficulty. In this example "1" is dark, like the shadow under a car during the day, and "9" is the sunlight reflecting off the car's chrome. Let's say you want to take a picture of this: 123456789. What does that mean? Let's put this in a slightly simpler way, with some arbitrary but easier to understand numbers. Google's HDR technology, used on the right image here, blends several underexposed frames into one final photo to boost dim areas while keeping unpleasant glare out of bright patches. It expands the dynamic range of the photo by preshooting and under-exposing images before you take the photo. It works largely the same as other HDR modes in phones, though it perhaps does a better job. The new Google Pixel has a camera technology called HDR+. Perhaps not quite as much detail as what's possible in the darker exposure image, but more than what we have now with our 8-bit TV system. That means more detail in the areas above that look blown out now. So for the above image, there could be more steps available in the bright parts. In addition, with 10-bit LCD panels and the right content, there will be extra gradations available. The same image on a non-HDR TV would look flat by comparison, with less punch in the bright areas. If you were to view the dark photo above on an HDR TV, for example, the sun would be very bright, with the dark parts very dark. It's not doing processing to "enhance" the image. TV HDR aims to actually expand the dynamic range of what you're seeing, not just enhancing TV contrast ratio. The idea behind HDR TVs (and HDR content) is to allow those images to be seen in the home. The professional-level sensors used in motion picture cameras can capture higher dynamic range images than current TVs are capable of reproducing. This is more like what I saw when I was standing there. Using Photoshop and Lightroom, I combined these to create the one image above that has both the shadow detail and the bright details. You can't have extreme brightness at the same time as shadows. This is the limitation of most mainstream camera sensors. It could be used to bring out some details in the shadows in a picture with bright sunlight, for example, or bring out details in the clouds near the sun. At the very least, it lets you capture a difficult scene that normally would be blown out or underexposed, depending how you set the exposure. Many cameras use up to six shots to produce HDR images in-camera, a process referred to as "multishot HDR."Īnd many cameras have an HDR feature built in. These are combined using processing, either in the camera or after, via software like Photoshop. In a typical two-shot HDR process, one exposure captures the bright information, the other captures the dark info. To create an image with a greater range from light to dark, HDR in cameras capture the same image at multiple exposures. The cheaper, worse or older the camera sensor, the less "range" it has (generally) to capture everything in one image. Getting really bright objects, like the sun, at the same time as objects in shadow, is really difficult. ![]() A camera sensor (and the rest of the processing involved) can only capture a limited range of light at one time.
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