Sunday, November 28, 2010

fun with High Dynamic Range (HDR)

These are pictures of my first attempts at HDR, or High Dynamic Range, pictures. A short explanation of HDR is:
  • In situations of high contrast in light, it can be impossible for your camera to properly expose a bright or dark area in one part of the picture without under or over exposing a different part the picture (the camera sensor has a limited dynamic range for a single shot)
  • HDR addresses this by having you take multiple pictures with different exposures, properly exposing different parts of the picture in different images
  • The multiple images are then merged later using software which takes the best exposure pieces of each picture and merges them into one image
There are a number of software programs available for processing HDR images, for these pictures I'm trying out a free demo version of Photomatix Light (demo leaves the "Photomatix" watermarks on my pictures you see here, $39 to purchase and get rid of watermarks).

My first photo above is an HDR composite of three separate exposures I took in Sedona, AZ yesterday. The dark sculpture was in the shade, with a much brighter sky and leaves behind it (no flash used).

Here's a better example. This is a foot bridge across Oak Creek at sunset last night. I would not have been able to get the above picture without using HDR -- the sky/redrock cliffs were still in full sun, the bridge in partial light, and the highly shaded creek bed below very dark in comparison.

To illustrate, I've posted my three exposures below which were then merged to make the above picture (remember, these are my very first attempts at this, so with experience this could be done much better).

I took the above picture with the exposure basically set on the distant redrock cliffs. Notice how the dark creek bed is very underexposed.

This this is a 2nd photo, -2 ev, (shorter exposure), resulting in darker sky / cliffs, and even darker creek bed.

and the 3rd exposure was +2 ev (longer exposure) which shows the dark creek bed, but completely washes out the distant bright sky and cliffs. The bridge is also better exposed.

This was a really nice place to experiment with HDR. It turns out to be easier than I thought. Some cameras, including my G12, have an exposure bracketing option which allows you to set the camera to take 3 pictures in a row, one normally exposed, one slightly underexposed, one slightly overexposed. That's what I did for these pictures. But, it is possible to experiment with HDR by just taking multiple pictures with different exposures. The software also helps to align the images from from the multiple pictures.

For best results the pictures should be taken on a tripod.

For my experiments, my first HDR photo of the sculpture was hand-held, the bridge series with the camera sitting on a railing, and the last sculpture (below) with the camera handheld but partly resting on the ground.

My third attempt -- looking up at a very dark sculpture up into a much brighter sky. No fill flash used.

I hope you enjoy these pictures as much as I did putting them together. I'm a convert. You will certainly see more pictures (certainly not all) posted over time on my blog where I use HDR techniques. And without demo watermarks on the images (smile). So far, I like what I've seen with this Photomatix software and after a little more research will probably end up buying their Photomatix Light version to get started.

There are a lot of techniques and available resources on the web about HDR techniques. I'm a total newbie and was very pleased with my novice attempts at a first try. Pretty cool stuff!


  1. HDR is new to me. I usually just point and click and hope for the best. ;)
    Great job of explaining and showing what outcome you can achieve.

  2. Jen -- thanks, I think its going to be an interesting area for me to explore, esp. on potential pics that I would normally not even try to take due to high lighting contrast. We'll see...


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