There are few techniques that divide the photographic community as much as HDR or High Dynamic Range photography. One person’s hyperrealism is another’s garish monstrosity. Some photographers use it to enhance tricky lighting situations, others to make striking shots from compositionally naive images. Either way, mention HDR and there is a good chance you will start an argument. So, what are we talking about today? Rather than tell you how to create HDR images or why you should or should not create them, we are going to give you a little information about the history of HDR, some of which might surprise you.
What is HDR?:
Before we go too far, and for the benefit of those who don’t know, lets look at what HDR photography is. Put simply it is a technique to create images with a higher range of luminosity that can be created with a single standard image. In other words, your camera’s sensor or film can capture a specific number tones between pure white and pure black. HDR is a technique to increase that number of tones beyond what can be captured in a single natural shot. Generally it is thought that the aim of an HDR images is to bring the tonal range of an image close to what the human eye can see.
When Did HDR Photography Start?
Many people assume that HDR photography is an invention of the digital age, an age where we all have the tools to easily produce HDR images. In fact, HDR is nearly as old as photography itself, the first examples being created as early as 1850 by Gustave Le Gray. He realised that when shooting scenes of extreme contrast such as seascapes, he had to compromise either the sea or sky to get an optimum exposure. His solution was to shoot two negatives, one exposing for the sky and one for the sea. He then combined the two negatives to create one composite print with an extended dynamic range. The technique was also used by other photographers of the era such as Hippolyte Bayard and to a lesser extent Camile Silvy.
The next development in the HDR story is also another technique that has survived into the digital era as well known Photoshop tools, Dodging and Burning. These days we tend to assume that HDR is created using multiple images, but the fact is, HDR can be any technique that extends tonal range. Dodging and burning are darkroom techniques that allow the photographer to either lighten or darken a specific area of the image. When dodging, the photographer uses his hand or a small opaque object to prevent light reach parts of the printing paper during exposure. For example if the image has an area of very dark shadows, the photographer would hold his had over that specific area for a period of time. This would reduce the light getting to the print, making that area lighter.
Burning uses the same technique only using a longer exposure to “burn in” for example the sky whilst holding back other parts of the image to maintain a natural look. Perhaps the greatest exponent of this technique was Ansel Adams.
The rise of colour film made HDR in the form of dodging and burning an impossible task in most cases. Some highly specialised films were developed using layers with different ASA sensitivities but these were confined to the realms of science and the military. The most well known of films was created by Charles Wyckoff and was used to capture full colour HDR images of nuclear explosions amongst other things.
Arguably the father of modern HDR is Greg Ward. His creation of the RGBE file format opened the way for cameras to capture HDR in realtime, initially in specialised video cameras. HDR in still imaging started in 1993 with the creation of Global HDR, a mathematical theory published by Steve Mann and Rosalind Picard. The theory described how to create tone maps from differently exposed images and combine them to one shot. The late Nineties/early Naughties saw the advent of software for “developing HDR images” In 2000, Greg Ward released Photoshere, a Mac application that allowed creation of tone mapped HDR images, this was followed by a number of other, relatively accessible applications putting HDR in reach of anyone with a digital camera. In 2005, Adobe released Photoshop CS2 with a built in Merge to HDR application offering full 32 bit tone mapping. Since then there have been a plethora of stand alone apps and application plugins that have made HDR part of the mainstream photographic world.
So What is the Future of HDR?
HDR is here to stay there is no doubt. As sensors and cameras' CPUs become evermore powerful, we are seeing the advent of live in camera HDR negating the need for post production, however, we may reach a point where the sensors can naturally capture a dynamic range similar and perhaps beyond that of the eye in a single capture. If that happens who knows where HDR will go. For now however, HDR is an important and long established part of our photographic history.