March 16, 2014 0
Recently I got lucky. Very lucky. Following a recent shoot I briefly put my camera down on the roof of my car to fumble for my keys… and watched it slide slowly off and hit the tarmac with a painful crunch and the merry tinkling of shattered plastic and glass. This was lucky for two reasons: firstly, because the camera was insured; and secondly, because it forced me to look for a new DSLR. And therein lay the serendipity!
One of the irritating limitations of almost all DSLR cameras to date has been their half-hearted implementation of the primary feature required by HDR photographers – exposure bracketing. This is the process whereby several shots of exactly the same are taken in a single burst, with the camera automatically adjusting the shutter speed so that each one at a different exposure. Most DSLRs can do this.
Subsequently these “bracketed” shots are combined together using HDR software on a computer to produce a single image with the full dynamic range of the scene (from deep shadows to bright highlights) all well exposed.
Nikons allow you to take 5 photos in a bracketed sequence, but they limit you to one stop increments. So the 5 photos cover a range of -2 to +2 stops: -2, -1, 0, +1, +2. In practice the -1 and +1 photos don’t add anything much to the process so to save processing time these often aren’t used.
Canons normally let you take only 3 shots in the sequence but they allow increments of 2 stops, so this results in a more practical bracketed sequence of 3 photos: -2, 0, +2. So this is pretty similar to Nikon.
The problem is that in many situations where there are elements of high contrast this range of 4 stops is not enough to properly capture the dynamic range of the scene. For example the common situation of a dark church interior with bright sunlight illuminating stained glass windows.
There are workarounds of course, but they’re fiddly and involve extending the bracket set by taking more photos at higher or lower shutter speeds. This is achieved by either: Manual shutter speed changes (with your camera on a tripod take several shots, carefully adjusting the shutter speed by 2 stops between each); or by exposure compensation adjustments (take a first bracketed set with exposure compensation at -2 stops, then a second set with exposure compensation at +2). But that’s all way too much trouble. Fortunately there’s now a much better way!
The Canon 70D has much more versatile exposure bracketing controls. It allows you to take up to 7 shots in a bracketed group, and in increments of up to 3 stops each. That’s a total dynamic range of 18 stops, which is as much flexibility as you’ll ever need!
Another key feature available on this camera which seals the deal for the HDR photographer is the “Custom” mode on the exposure selection dial. This can be programmed with your preferred HDR setup, including number of bracketed shots (usually 3, 5 or 7), bracketing increment (1, 2 or even 3 stops), and an initial aperture and iso. To switch from standard photography in Aperture Priority mode to HDR photography is then just a simple twist of the dial and you’re immediately ready to go. So, for example, you can quickly switch to HDR as you walk into that old church, and just as quickly switch back to Av as you walk out. Its perfect!
In the next post I’ll show you some how I use this camera to easily and quickly make great HDR photos, even without a tripod.
In Other News
The news is bad. It always is! Read any newspaper or watch any TV news channel and all you see is war, nasty politics and misbehaving celebrities. One of the best examples of incessant bad news presented by paranoid and hysterical reporters and fully intended to outrage and horrify us is the UK’s Daily Mail. To this laughable journal of scaremongering schlock and depraved trivialities everything appears to either cause or cure cancer, and everything else is the fault of immigrants!
But now there’s a great alternative. The English philosopher Alain de Botton has written a new book about the adverse impact of the news media on our lives and our wellbeing. And to try to counteract all that relentless negativity and nastiness he and his School of Life have started their own online alternative, The Philosopher’s Mail. It looks at stories currently in the news and tries to present the same information in a “nicer” more positive and productive way. Give it a try – its a concept that we should all support.Leave a reply