Thursday, December 8, 2016

HDR Photography....A Few Thoughts

Pillar Point Harbor, California!
High Dynamic Range HDR photography uses multiple exposures at a wider range F stop to extract more information from a photo scene!  This is not a new technique some early examples are evident around 1850 by Gustave  Le Gray who combined two B&W images to capture detail in a sky and sea image! 
Today there are HDR stand alone programs, HDR filters for Photoshop plus many cameras now process and generate HDR within the camera. I use a stand alone program called Photomatrix which I'm pleased with. Once you get certain parameters set, it delivers good results.

Here is my rudimentary understanding of HDR and why I find it useful under certain circumstances! Our eyes take in a lot of photographic information, more so than a camera. To relate HDR and our eyes you can equate F stops in a camera. If you consider the human eye is equivalent to about 24 F stops, whereas an ordinary digital camera maybe 10-14 F stops, some think 5-9 F stops is more realistic. So it makes sense if you can shoot multiple photos with a range of exposures say +1, 0, -1 you have more data or information that can be combined into 1 photo!

HDR is not without criticism as some people tend to over process their photos that results in unnatural elements in the photo. It should be noted that HDR does not add or subtract anything from a photo, everything contained in the photo was present at the scene and time of the shot! Any out door scene has continually changing light dependent on the earths rotation, the sun and cloud position! A photo taken at 3 pm will be different than the same photo shot at 3:05 pm as lighting is constantly changing for the reasons given above! Most photographers post process their work, whether a simple crop or adjustments of color and lighting.

I've done a lot of backpacking in the past and always carried a decent camera and lens. However I was usually disappointed at the final results, because the camera was not capturing correctly all the information present with one shot. Not being a professional photographer I was unaware of multiple shots and dark room skills. One of my first experiences with HDR happened on a trip to Sierra Valley in California when a thunder storm appeared and presented wonderful lighting and dramatic clouds!
I was very pleased with the results but when I showed my wife the photo, she said it did not look real. I then showed the photo to one of my friends who was on the trip with me and experienced the same scene, he immediately said that's exactly how I remember the scene!

Another aspect of HDR I'm experimenting with is taking photos directly into the sun! All photographers know taking photos directly into the sun is a bad practice and results in poor back-lit photographs. I've found you can take photos directly into the sun as the group of photos show below. The sun is just above the top frame of the photos, I cropped to make sure the sun itself was not in the photo.  The one major drawback is this technique generates lots of digital noise and extreme noise reduction post processing is necesary.

HDR Example Shooting directly into Sun

HDR 1of 3 0 Exposure Adjust

HDR 2of 3 -1 Exposure Adjust

HDR 3of 3 +1 Exposure Adjust

HDR Final Version