You may have heard the term HDR before or you may have even seen it on your phones camera settings, if it is used correctly you can create great photographs. HDR stands for “High Dynamic Range”, The dynamic range of an image is the ratio of the maximum and minimum light intensities, essentially how dark are the darkest and how light are the lightest and how they interact with one another.
Our eyes have a dynamic range of somewhere around 11 f-stops, whereas most DSLR’s are around 9 f-stops and camera phones are around 5 f-stop. Our eyes can see a much better dynamic range than a camera can, and you may notice that sometimes when you take a photo it doesn’t appear as you see it with your eyes. This is mainly down to the capability of the sensor in the camera not matching our eyes capabilities.
Example of a low dynamic range photograph: The sky and sunset are exposed correctly and look good but there is no detail in the foreground and it appears underexposed.
Increasing the Dynamic Range
In order to combat the deficiencies in the cameras capabilities we use a technique called “High Dynamic Range” (HDR) photography. The specifics on how you personally go about capturing a HDR photograph can vary, but essentially it requires taking 3 photos of the same subject at 3 different exposures. The 3 separate images will capture different lighting intensities in a scene within the normal dynamic range of the cameras sensor. As each of the 3 photos are captured at different exposures, they are capturing details of the scene at their respective exposure.
The 3 images are then combined in software which can give you up to 14 f-stops of dynamic range, which is why it is known as a High Dynamic Range photograph. The range of a HDR photo is much more similar to that of your eye which results in images that look much more like how they look to you through your own eyes.
When to use HDR
You may now be thinking that I should be using HDR all the time if it equates more closely to how my eyes see, but you don’t need to apply HDR to every situation. Usually it is only required if there is a large range of light intensity in the scene you are photographing, if there isn’t then your camera will capture the full range of the scene with a single capture.
Sunrises and Sunsets
Sunrises and Sunsets are great candidates for HDR photos because there is a big difference in the light intensity of the bright colorful sky and the land. Using HDR will allow the sky and land to be visible at the same time.
Landscape shots that cover a large area usually have a lot of contrast between the sky and the land, so these are also great for HDR shots.
When to avoid HDR
As HDR shots usually require 3 different exposures, the longest of the exposures can be quite a slow shutter speed so if there is any movement in the frame they can come out blurry. As you can see in this example the traffic is blurry.
The HDR process tends to bring colors back into images, but if your subject matter already has vivid colors they can appear over saturated or add an unwanted tint to the image. In this example the colors are too vivid and appear unrealistic.
I would suggest to generally avoid shots of people, at least if they’re close up as the HDR process will make a persons skin look strange and unnatural.
Bracketing with DSLR’s
When taking HDR shots with a DSLR camera you will have to take 3 separate shots. There should be a setting on your camera that enables you to do this easily, its might be called bracketing or something similar.
Smartphone HDR setting
Nowadays most smartphones have a HDR option on the camera that can be turned on, the phone will take the 3 shots for and merge them all at once. This is useful for quick shots and the results can be good, however I personally do not like the lack of control as the shots are merged for you and you are unable to adjust the result in any way.
When you are taking HDR shots a tripod is usually used, it depends on the situation of course but they do make things easier when dealing with low light shots. This is because the shutter speed can be quite slow and the shots will come out blurry if the camera isn’t kept completely steady.
If you are still unsure when to use HDR in certain situations, just try and experiment with it and you will soon discover when its appropriate or not. I hope you have found this information useful and are able to create some new HDR shots, i would love to see your results. If you wish to share just post in the comments.