Tuesday, 29 November 2011

Infra-red photography

I've recently had my attention drawn to infra-red photography.
Not the most ideal time of year for it but still.

There's a few ways to do such photography, the most expensive way is to buy a specialist camera or have a camera physically modified to remove in-built filters that purposely filter out light from the appropriate end of the spectrum... The red end I guess.
The cheaper method, the method of choice for folks such as myself, is to use a filter, these come in varying strengths, restricting the spectrum of light that can pass through the lens to the cameras sensor. The result of which, in camera, is a black and red photograph of, whatever you should choose to shoot.
For a better explanation here's a wikipedia link...

Some cameras work significantly better than others and, fortunately for me the D50 is fairly good for it.
Most folks convert IR photographs directly into black and white images but, with some jiggery pokery in software to get the desired white balance and colour temperature compensation, you can squeeze a bit of colour here and there. The shades of colour you get as a result can differ as per taste/technique however the effect of infra-red photography is quite consistent.

The effect can result in an image that looks quite alien but not quite unrealistic. At a glance it might seem like the image is a mere colour negative of reality, however the specific focus of infra-red light that is captured has a notable effect.
The most noticable effect is that blue skies tend to be darker whilst green plantlife glow up brightly infront of it. The more sunlight the better and the greener the plants the more drastic the effect,while other surfaces tend to appear relatively consistent with reality (though in duo-tone.)

Here are some images from my first trip out using some cheap filters I nabbed off of amazon, it's worth noting that you can't use the auto-focus and as infra-red is a slightly different frequency you'll have to offset the focus ring slightly to compensate. I did this via trial and error myself so it's difficult to explain it precisely, also expect shutter speeds to be long due to the volume of light being restricted through the lens, so bring a tripod.

Here is another set, from a familiar location, near my place of work a few weeks after the above set.
I'd had a little more practice by this time so I believe the standard of images is a little better myself.
This last image is a panoramic stitch of several portrait photographs.