A Very Basic Intro to HDR

The human eye is a wonderful thing.  It can take in details in the highlights and shadows in a scene; combine them in the brain; and we see the whole image.  The camera does not have this capability – yet.  Believe me, they are working on it.  What do you do in the meantime? The difference is the dynamic range of our eyes and brains versus the lens and sensor of the camera, and we still beat the machines.  We have all seen the results in photographs.  People with their cameras set to the “Program” mode will show you their images with a subject near a bright light source and a couple of silhouettes or pictures of people surrounded by a bright light and burned out skies.  The camera cannot handle the extremes between the shadows and highlights.  Let's take the camera off the "P" and try this technique.

If you don’t have a program like Photoshop, you should expose for the highlights and add some flash to light the subjects.  Most new photographers never think of using flash in the daylight, but it can really make quite a difference.  If you can control the amount of flash output, you can blend the flash into the scene so that people won’t even know it was used.  This works well and allows you to get a feeling of a greater dynamic range within the camera.

If you use Photoshop, you can buy plug-ins that assist you in creating a high dynamic range (HDR) image.  I don’t usually use this technique, so I haven’t bought any of the HDR plug-ins.  You can still take advantage of Photoshop to create an HDR if you take your time and plan out your workflow.

The first step is to pre-plan the images.  In order to bring all the variations of the scene into the computer, you usually take 3-5 images of the scene, with a constant aperture and varying the shutter speeds.  Shoot at least one image slower than the camera solution (constant aperture) and one faster than the camera solution.  This produces images that are properly exposed for different portions of the scene.  For the best result, you should use a tripod to keep the framing of the scene constant.   So you get three images like these:

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You can see from the images that I didn’t use a tripod on these (I was on a photowalk). I imported the images and aligned them in Photoshop.  Once aligned, they were combined into a single image that more closely represents what I saw.  Yeah, I did a little tweaking, too.

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We don’t go into all the details on this blog, but you can find instruction about this technique all over the web.  So, grab some images and have fun creating an image that can’t be done inside today’s cameras.