In this tutorial we will take a look at HDR photography. HDRI (High Dynamic Range Imaging) was originally used in 3D and is now in full force in photography. Basically it's the process of taking multiple exposures and merging them together into a single 32 bit image. Let me explain: A camera is capable of capturing a limited amount of tones in a single photo. Typically we sacrifice elements in a photo when we press the shutter. For example there is a powerful cloudscape and some cliffs. If we expose for the clouds the cliffs become dark. If we set the camera's exposure to capture detail in the cliffs, the brighter sky is blown out and detail is lost. This is because the human eye can see a larger range of tones than the camera can capture on the chip or film in a single photograph.

The solution is to take more than one photograph and bracket the photos. Shoot normal exposure, then under-expose a shot to capture highlights and over-expose a shot to capture shadow detail. Finally, merge these photos together to produce a single image with a larger range of tones that can now show all the details in the shadows and highlights. This tutorial will show you how to complete this process with the minimum fuss.

First we need to get our source images. (You could begin with a 32 bit 3D image and then skip to step 6). Typically we will capture these with our camera. You will need to shoot a minimum of 2 photos with different exposure settings.

Its been recommended by Adobe to limit the bracketing by 1 stop and this will help reduce banding. You may also take 5 or more shots with a smaller gap in the bracketing. I personally get good results from 3 shots. I like to over expose and under expose by 2 stops. I know this is a bigger bracket than most people are comfortable with, but for the type of HDR images I like to create (cityscapes), this works great. If your shooting people, you may want to reduce this to even 3rd stops.