One of the joys of photography in the current digital era is that in our creative endeavour to see the world in a new light, we can experiment with techniques that previously would have been difficult to achieve or restricted to a small group of aficionados. Colour Infrared is one such area in which we can experiment.

 Today we have Photoshop and the host of other software post production packages that have become not only our dark room, but even our studio, with the opportunity to utilise a vast range of adjustments or combine effects from our cameras with graphical treatments that would previously have required whole art departments. Experimentation has always been at the heart of the photographic craft from the earliest pioneers in silver halide and all of these ideas are of course open for us to revisit today should we be so inclined.

With this in mind and while leafing through some old album covers from the 60s, I was struck by how much experimentation photographers and designers in the psychedelic era were doing with colour IR (infrared), with its dreamy, out-of-this-world characteristic look.

Anyone familiar with the music of the time, for which album cover artwork was such an important part, will probably remember the Frank Zappa cover for ‘Hot Rats'. LA photographer Andee Cohen Nathanson had used colour IR to capture a strange, almost opaquely white, frizzed model apparently climbing out of a crypt against a background of bizarrely red foliage.

Then there were further examples from seminal 60's British rock photographer Karl Ferris on such legendary cover work as the Hendrix ‘Are You Experienced' album and a host of Donovan covers such as ‘Wear Your Love Like Heaven'. This cover featured a strangely purple castle in the background and again the surreal red foliage hanging over the reclining Donovan.


Colour Infrared Photography

The Gateway

Perhaps slightly lurid by today's standards, but I was intrigued to see if colour infra red could be used in a gentler style, maybe more sympathetic to the natural environment, or perhaps mixed with some of the effects of black-and-white IR, but where to start?

I hate to knock any film because generally I love using it, but several years ago I had used black and white infrared (IR) film leaving memories of how difficult it was to use. IR film, both B/W and colour, is also getting increasingly difficult to source these days let alone get developed. It is highly sensitive and needs to be loaded and unloaded in total darkness. Some cameras have infra red sprocket counters that position the film and can fog it around the sprocket holes, which gives some idea of the sort of problems IR film users can expect to have to deal with.

An infrared filter is needed to allow only infrared (IR) light to reach the film in the camera, while blocking most or all the visible light spectrum. The problem here is that the filter accordingly reduces exposure considerably and looks black or deep red to our eyes. Impossible or difficult to see through, it effectively blocks the viewfinder while the filter is in place and exposures will be too slow for hand holding. The lengthy and complex procedure with infra red film therefore is to place the camera on a tripod to counteract the long exposure times which can be seconds long, then compose and focus without the IR filter in place, replace the filter and then adjust focus for infrared. Now we're ready to shoot, but wait, bracketing will also be necessary as IR films only have nominal speed ratings which vary depending on subject and conditions!


The good news is that it is possible to greatly simplify the infrared photography process in the digital world of today. Some DSLRs are better than others, and digital infrared photography is possible with an unmodified digital camera, but an infrared filter is still needed in front of the lens as with film, so exposures are still long, in most cases requiring a tripod. Alternatively, if you are prepared to pay for a dedicated digital IR camera, Fuji have developed 2 cameras specifically designed for digital IR photography. Based on the Nikon D200/Fuji Finepix S5 Pro, Fuji's pro'spec IR camera, the IS Pro can take interchangeable Nikon fit lenses. Fuji also introduced a cheaper infrared bridge-camera, the IS-1, a modified version of the Fuji FinePix S9100. Both cameras have increased sensitivity to infrared light,but as they record visible light as well, they still need an IR filter on the lens to record infrared. Live view on the IS Pro and the EVF (Electronic Viewfinder) on the IS-1 help to mitigate for the fact that a filter still has to be used, but at around £1,400 and £400 respectively these are not the cheapest or easiest options for digital IR. A more economical alternative is to adapt an existing DSLR, perhaps that old model that sits in the cupboard or was eventually going for trade-in for next to nothing! The latest digital cameras are sensitive to infrared light, so manufacturers place a ‘hot mirror' filter in front of the sensor to block infrared light.

 

Once this filter is removed, and replaced with a filter that allows IR to pass, it becomes possible to photograph infrared images without the need for visible-light blocking infrared filters on the lens, opening up the possibility of hand held IR photography even at low ISO speeds, a real revolution!

Since you no longer need to use an infrared filter in front of the lens, the whole process is vastly simplified all round, for example you can change lenses easily, compose through the viewfinder which is no longer blocked and focus much more precisely.

Although you can do this yourself, (some cameras like the Sigma SD14 with its unusual Foveon sensor has a combined anti-IR filter and dust protector close to the lens mount that can apparently be easily removed without major surgery), it is still a job best left to an expert.

There are a number of specialists advertising on the Internet and with the imminent arrival of the Canon EOS 5D MkII, I decided to have my old 5D converted by Life Pixel in America; I liked their site www.lifepixel.com which had some useful examples and tutorials which gave me confidence. There are 2 main choices of the degree of adaptation available for colour IR, dependant on what needs you have or what effects you intend to achieve: ‘Standard IR', which is equivalent to Hoya R72 / Kodak Wratten 89b / 720nm, is described as an all round filter choice.

In the event my camera was back in a little over 3 weeks allowing for a short hold-up in US customs and I was eager to try it, but for IR to work well, you need sunlight and that's something we haven't had a lot of this summer! In the end it was weeks before suitable conditions arrived, with bright sun to bring out the foliage and good cloud formations to stand out against dark blue skies.

Life Pixel also calibrate the filter to allow for the infrared focus shift, either to the standard 50mm f1.8 lens or another lens of your choice for a small extra fee. In the event, I found the standard lens focus compensation worked very well with both my wide-angle zooms. To allow for any slight focus variations that may still remain, it is worth using a smaller aperture around f8 to f11, which gives plenty of depth of field on wide lenses and so will usually take care of any focus issues. In the event, either my camera allows more colour information to pass (DSLRs do vary), or Life Pixel have given me the ‘Enhanced' colour IR filter by mistake because it immediately became apparent that I was getting results with much more than just the ‘blue sky' effect. Whatever the reason, I am more than happy as I now have the option of going as luridly psychedelic as I like bringing back fond memories of those old album covers! Alternatively I can tone things down in Photoshop for some subtle and creative effects or remove all the colour and have very effective B/W IR. Like all things creative, IR is very much a matter of taste, but I haven't had such powerful images from my camera for a long time. This is a new way of looking at the world allowing the creative flow to move in new directions and after all, no artist should be afraid of trying a new palette, it is one of the great advantages of living in the digital age!


Infrared Film  

Infra red film is sensitive to the part of the spectrum known as ‘near-infrared' as opposed to ‘far-infrared', which is used for thermal imaging. Wavelengths used for photography range from about 700 nm to about 900 nm, the human eye is sensitive to wavelengths up to around 700-720 nm, so the film is picking up waves above the range of human sight and a deep red filter is needed to prevent the visible light fogging the highly sensitive IR emulsions.


 Digital IR Conversion  

Modern DSLR sensors are sensitive to the IR light that is not required for normal photography, so manufacturers place an IR blocking filter in front of the sensor. By removing this IR filter and replacing it with a filter that removes visible light but allows the IR to pass, the camera can be used almost normally. Shutter speeds can be close to those in normal visible light photography meaning handheld IR is now possible as well as clear unobstructed view through the viewfinder making composition much easier. With some minor adjustment, even A/F and manual focus will work like a normal camera.


Focus in IR

Infrared light has a longer wavelength than visible light and our visible light balanced cameras and lenses focus at a different point. To counteract for this different focusing of visible and infra red light, many lenses display a red focus dot beside the normal focus indent so that once focusing is achieved in visible light, the distance on the focus ring can be re-aligned with this red dot to compensate for the focus shift in infrared, but this is not an exact science!



Colour infrared is possible although not as saturated as the ‘Enhanced' filter. Only a blue sky effect is possible with this conversion. Black & white IR photography is also possible with good tonal range. ‘Enhanced Color IR', equivalent to 665nm, apparently allows more color to pass through and is especially designed for color IR work with ‘great saturation and color range'. B/W is also said to work well although with a bit less contrast without adjustments. Life pixel also offer an all B/W adaptation called ‘Deep BW IR', equivalent to Kodak Wratten 87c / 830nm, which is apparently best for black and white infrared photography with very dark skies and bright foliage, if that's the route you want to go down. As very good B/W is also possible with both the colour filter options by just removing the saturation and playing with contrast, I decided the most flexible choice would be to go for one of these colour options. I chose the Standard IR filter which at $500 or around £250 at the prevailing exchange rate seemed good value. Sending your cherished camera all the way to the US takes a bit of nerve and it's worth packing it well and making sure it is well insured. If you have second thoughts, it is worth remembering that any such work will invalidate the camera's warranty, but most of the specialist outfits will reverse the conversion if required.

Tips for using an IR converted DSLR  

Try varied white balance settings for different effects rather than leaving the camera on auto white balance which can result in heavily magenta tinted ‘pink' images straight out of the camera. Exposure can vary widely depending on the IR reflectance of different subjects. Use the histogram and adjust shutter speed or aperture to ensure the result sits in the middle of the brightness range. It's best to shoot in RAW to allow the most control of the image in post production. Don't be put off by the apparent lack of contrast in images straight out of the camera. Levels and curves can work wonders in improving the tone and impact of IR images. Unadjusted images will have the hallmark magenta cast of IR. For the ‘blue sky' effect, try changing colours with Hue/Saturation. Alternatively go to the ‘Channel Mixer' and reverse the Red and Blue channels. A combination of adjusting the white balance ‘tint' control in Raw conversion followed by Photoshop ‘Photo Filter' to enhance the false colour effects can have very interesting and sometimes quite subtle, pastel like results (See above).