Originally Posted by PattiCakeUS
At the risk of sounding stupid, I'm just going to ask.... what's HDR?
It stands for High Dynamic Range, and that refers to the amount of contrast captured in the final image. With a regular photo, the dynamic range captured is much less than what our eyes can perceive. Therefore, shadows look darker, and bright areas get washed out much more easily on paper than it does with our eyes.
HDR requires that you take several photos in quick succession at different exposure levels, taking care to capture the details of the shadows, the midtones, and the bright areas. No one photo can capture it all, but through a post-processing technique called tone mapping, you can merge the best contrast ranges from each photo into one. The resulting image is what people refer to as the HDR shot. It allows us to capture light that more closely matches what we can see with our eyes. Extreme tone mapping can also capture more of a dynamic range of contrast than what we perceive, and when this happens, the HDR image has a surreal feeling, like things are glowing.
When we take an HDR shot with our phone, the phone is taking three shots in rapid succession, one underexposed to capture bright contrast; one normally exposed to capture midtones, and one overexposed to capture shadow details. Then the images are tonemapped and saved as one image.
HDR worked better for me at night because one of the shots was an overexposure, and I'd imagine most of the data from the final shot came from that one. The other two would be near solid black.