High dynamic range images (HDRi) are created through the manipulation of several superimposed images by special software. Generally, the idea is to take on more than one image of the same shot using a different exposure each time. For example, I have taken three images below. The first is a normal mid-range exposure (EV 0), the second is underexposed (EV -2), and the third is over exposed (EV +2).
The images need to all be aligned exactly, and some software does this automatically. To avoid an discrepancies in alignment, use a tripod for best results.
I’ve found out that my favorite software for creating HDR images is Adobe Photoshop due to its wide range of tools which all have a powerful ability to correct images.
If you own Photoshop, there is a built-in automatic “Merge to HDR” function. Go to File>Automate>Merge to HDR. Now browse for the images you would like to work with, and make sure “Attempt to Automatically Align Source Images” is selected, unless there is a reason the software my make a mistake in alignment due to ripples in water, moving subjects, etc.
Depending on your computer’s ability and the size and format of the images you input, Photoshop may take a while to “crunch” these images. When these intense algorithms finish computation, a dialogue box opens with the HDR. in the top right, you are able to adjust the brightness. This does nothing permanent to the image, but only enables you to see it better since it’s a 32-bit image (our computer monitors do not have to ability to display these). In the left, the images are listed, and if you see that an image is harming the overall effect, you can uncheck it and have it removed from the HDR. Otherwise, leaving the bit depth to 32-bit per channel, click OK.
Now you have an HDR image that you can manipulate with Photoshop’s amazing tools. In my next post, I will go over some different Photoshop techniques on how to get the most out of an HDR.
Tech Tower, Georgia Institute of Technology, Atlanta, Georgia
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