High Dynamic Range is referred to as HDR and is the art of using different exposures to process one, or a series of images. The amount of light is compressed in the photograph so it can be displayed on a computer in print. HDR photography ensures bright backgrounds and foregrounds are properly exposed. The result is a fantastic picture. Expert, D. Scott Carruthers, explains how it’s done.
Using HDR Photography
The way to begin is to take three photographs using different levels of light. This can be accomplished with a multiple exposure setting or bracketing. The bracketing should be set to increments of 2 EV to ensure the first photograph is too dark. The next photograph will have proper exposure at zero EV, and the third will be overexposed, or too light at plus 2 EV. The camera should be set at aperture priority since this will prevent the shutter speed from changing.
The result is three photographs with a blurry HDR image and different depths of field. Noise in the HDR image can be eliminated by setting the ISI to the lowest setting. If possible, using a tripod is helpful. These photographs should be taken in the RAW. This type of photo is similar to a film negative. The light information far exceeds a jpg image, so amazing adjustments can be made to highlights and shadows. Although not possible with a jpg, any exposure errors can also be fixed in a RAW photograph.
Uploading and Processing the Photographs
The photographs are now uploaded into a computer, then saved on the hard drive. Software designed to process HDR photographs is required to process the photos. An excellent option is Photomatix Pro. This software is cost effective, very good, and can be installed as a plug-in for both Photoshop and Lightroom. Generally, the stand-alone program works best. It is easier to use and install.
Using the Software
Once the software has been installed, convert the photographs into tiff or jpg files. This is easily accomplished with photo processing software such as Photoshop. Now the converted files are imported into the processing software. When the HDR image is created using tiff or jpg files, the noise in the finished image is greatly reduced. If the photograph is of a moving subject, one RAW file can be used to create a pseudo HDR image. This is the easiest way to create an HDR photograph when the subjects are moving. The finished photograph will not have the broad dynamic range of a stationary image.
Open the software program, and select generate HDR image. Choose the three images taken with bracketing. The selection of align source images will align the images. This will compensate for any minor imperfections in the framing. Even with a tripod, there can be very small shifts between the individual shots. It is also helpful to select reduce noise and reduce chromatic aberrations. If there were any objects moving in the photographs, select background movements, and attempt to reduce ghosting artifacts. If this is not selected, the HDR image will be blurry due to something small such as foliage or grass moving from a slight breeze. This feature can only fix minor movements.
The default setting should be selected for color profile tone curve. The software will require a few minutes, and this depends on the speed of the computer processor, the size of the images, and the number of images. When the software has finished, you will have your first HDR photographs.
Scott Carruthers enjoys numerous activities when he has free time including photography, adventure travel, scuba diving, recreational golf and football. Carruthers is a resident of Anaheim, California where he also has his photography studio.