High Dynamic Range (HDR)

This is another topic for advanced users but perhaps one everyone will enjoy.  There is one inherent problem with digital that the camera manufacturers have been unable to address so far.  The problem is even the best digital sensors used in the most expensive digital cameras made, do not have the dynamic range (the range from the brightest to the darkest point) of even the cheapest film.  This means when the scene has a range of light that exceeds the dynamic range of the sensor, that you must compromise your exposure to clip either the highlights or the shadows.  This severely reduces tonal range and it almost becomes a matter of luck to get the rich tones you’re used to seeing with film.  This isn’t a problem with most scenes, but it is a problem with the most beautiful landscapes and this is why some of the best landscape photographers are still using 4x5 and 8x10 films.

There is a digital solution!  However, it takes a bit of work.  Using a program like Photomatrix from HDRsoft you can combine images of the same scene taken at different exposures and drastically increase your dynamic range.

Three different exposures

Notice the three images above?  Each a different exposure.  If you combine them in Photomatrix you can increase the dynamic and tonal range and get the resulting image below.


The technique used during capture is fairly simple.  If you have a DSLR capable of at least four frames per second you can set your camera to auto bracketing, set it for 2/3’s of a stop between each exposure, put your camera in Av (aperture priority mode), meter as you would for a regular image, brace carefully, and with the single press of the shutter button you will capture three images 2/3’s of a stop apart.  The critical part of this is twofold.  You need excellent hand holding technique, and the aperture must always stay the same.  And this only works on scenes without anything that moves fast like wind moving branches, moving water, or fast moving clouds.  The scene must be nearly static.

HDR-Rice field

A better way is to carefully set up on a quality tripod, use mirror lockup, an external shutter release, meter for the aperture you want in manual mode, and then carefully take 5-8 images 2/3’s of a stop apart, 2-3 up, and 2-3 down from your original metering point.  This will give you a wide range of exposures of the same scene to combine.



This last example (below) shows the rich tonal qualities of the best black and white film.  It was captured by combining seven exposures in Photomatrix and then carefully tone mapping the resulting image.  Notice the very wide range of tones?  Using this technique you can create digital images that rival any film, or even exceed it.