High Dynamic Range Photography (HDR)

HDR, Detail of the Wigwam Hotel, Holbrook, AZ

www.dennismook.com

What is high dynamic range photography (HDR), why do we want to make high dynamic range images and how do I make them?  Can an HDR image look natural or are they always "over the top" and garish as I have seen them on the web?
After returning home, do you look at some of your images and feel disappointed because you didn't capture all of the detail in the shadows or highlights or the textures, etc., and your photograph didn't turn out the way you were hoping?  HDR can help.

High dynamic range photography is term used when the photographer combines or composites several images into one to be able to display (render) all the luminance (brightest to darkest) tones in one image. 

Sometimes we want to photograph a scene that has tones from extremely bright to extremely dark.  For an example, blowing white sheets in sunlight in front of a cave entrance in which you want to show petroglyphs just inside.  I don't know why you would want to photograph that, but let's use that as an example.  There is no way film or any digital sensor can successfully record all of the tones in the above example.  The dynamic range (brightest to darkest tones) is too great.  Some tones would be lost.  If you decided to keep the delicate white tones in the white sheet, the cave entrance would be totally black.  If you set your exposure to record the petroglyphs just inside the cave entrance, your white sheet in the sunlight would be totally without detail and look like a white blob in the image.  How do you record all the tones to make a satisfactory image?  High dynamic range photography.


Five images combined as an HDR image and processed to look natural.
Notice the bright daylight outside is rendered normally as well as the dark inside.

In our example, the photographer would take several different exposures of exactly the same composition.  The camera would not be moved.  He or she would make an exposure so the white sheet shows texture and make an exposure where the entrance to the cave was dark, but the details of the petroglyphs would be clearly visible, while making several exposures in between the two extremes.  Typically, HDR imaging requires a minimum of 3 exposures.  There is no number of maximum images, but typically one makes 3, 5, 7 or 9 images to blend together.  The images are typically taken about 1 f/stop apart, or double the exposure for each image.  The point is to capture the brightest detail and the darkest detail plus capture all of the mid-tones.  You are always better off taking more images than fewer.  Err on the side of too many, always.  You don't have to use them all when making your final HDR image, but you have them if you need them.

Getting back to the computer, the photographer would composite all those images together to make one that captured the brightest tones, the darkest tones and everything in between.  There are several software programs that will allow that to be easily accomplished.  First, Photoshop has that capability.  Also, Nik HDR Pro 2.0 (now owned by Google) as well as Photomatix 4.2, by HDRSoft,  can also easily accomplish it.  There are some other programs, but I don't have experience with them.  I do know that these three mentioned here work wonderfully and give slightly different outcomes.  All three give you lots of controls so you can tailor your final image to what you envision.  Sometimes, I will make an HDR image in all three to see which one I like best for that particular image.  The process is pretty straightforward and if you want more information, there are many tutorials available at the manufacturer's websites, You Tube and especially look at Trey Ratcliff's site, Stuck in Customs, for a free, extensive tutorial.


Same image as above, but with the typical HDR look.
There is a place for both methods, depending upon your vision.

HDR imaging has come under fire because most people make a final image that looks really artificial with oversaturated colors, halos around darker detail and even very grungy looking.  That is fine.  Everyone gets to make what he or she likes.  But you don't have to do that if that is not your vision. 

You can also use HDR as a true tool to capture the tones that otherwise would have been lost, but still result in an image that looks natural.  You can do that by using Photoshop and, instead of having Photoshop tone map your images, change the mode to 32-bit of the combined image, then make your adjustments in Camera Raw.  Or, if you are using Lightroom, export to Photoshop for combination into HDR, then instead of Photoshop tone mapping your image, change your mode to 32-bit, click okay, then save it back to Lightroom.  You then can use Lightroom's Develop Module to make your final adjustments.  This is what I did in creating the image at the top of this post.

If you are interested in making HDR images, do a bit of research.  You may need to acquire a piece of software, but that is what we now do in photography.  Most digital cameras will auto-bracket so you can even hand-hold your camera if you are really steady and careful.  These images on this post were handheld.  The only real problem you may encounter is with moving subjects or parts of subjects.  For example, tree leaves blowing in the wind or moving water.  Those take some extra effort to make sure they appear without ghosting, but now the newest versions of the HDR capable software even handles most of that automatically!

Go out and try some HDR.  I think you will enjoy expanding your vision and capabilities and make some really pleasing images.  If you have any questions, I will be more than happy to help.

Thanks for looking.

Enjoy!
Dennis Mook