So what is infra red light? Think of the cover to Pink Floyd's seminal 70's album (showing my age here?) Dark Side of the Moon. It shows white light being refracted through a prism, displaying the entire visible spectrum; violet, indigo, blue, green, yellow, orange, red. That's the range we can see with the naked eye, and so when Louis Daguerre and Fox Talbot were concocting their first light sensitive emulsions back in the 19th Siecle the aim was to replicate the sensitivity of the human eye, and that, by and large, is what films and now digital sensors have done ever since. But beyond the two ends of the spectrum there is light bouncing around the atmosphere that we can't see; ultra violet at one end, and infra red at the other. Many animals can see these rays; kestrels use ultra violet sensitive vision to see vole pee. But we can't. So why should we try? I don't need to see vole pee.
‘Cos it looks neat. Your classic infra red monochrome landscape has white clouds against black skies and seemingly luminescent foliage. Impact, un je ne sais quoi, a definable look. Minute particles in our atmosphere reflect the shorter wavelengths at the blue end of the spectrum. It's why the sky here in Provence looks so blue. It doesn't happen quite so much in Merseyside but you get the idea. The UV light so dispersed causes haze, a landscape photographer's curse, but the longer wavelengths at the infra red end slice straight through the atmospheric grot, giving IR landscapes a clarity totally devoid of haze for even distant views. And as those same longer IR wavelengths are not reflected by the tiny floating jobbies in the atmosphere, they pass into space unmolested and lost to the world, so skies appear black. In spring and early summer all the photosynthesis going on in plants causes leaves to reflect infra red, so foiliage looks almost white. And this is just the start. Learning how different subjects reflect and transmit IR light is all part of the game. Photographically it's a whole new world.
So enough theory, how's it work in practise? In the film era shooting IR was a somewhat haphazard affair. The film had to be loaded in total darkness. I don't want to think about what the chambermaid at my Paris hotel thought when she disturbed me fumbling under the duvet behind drawn shutters in the middle of the day with a Nikon FM2 and a roll of 35mm Kodak IR film. Exposure was a matter of guesswork; 1/125th @ f11 and bracket like mad. Ditto focusing, I had to manually offset the focus point by…well, a bit, and hope the small aperture would save my bacon. It worked, but the film was horrendously soft and grainy. That I guess was all part of the look. But now My Life Has Changed.
I've had my “old” Canon 1Ds mkII converted for infra red. It's a one way process; this camera can now only be used for IR work. I take a picture and all I get on the monitor is a red image. But with this conversion I can shoot, meter exposures and focus just as normal. Forget about using IR filters, if you want to do digital IR photography this is the way to go. And let's face it; even though the 1Ds mkII has been left behind by more recent cameras it is still capable of producing a big 16.7 megapixel full frame high resolution image that makes the old 35mm IR film look pretty sick. I am excited. It's official.