Friday, 22 April 2011

Digital Infrared IR Photography

This is a guest post from Guy Dawkins, a very talented photographer with a fascinating day job!

The sun is out so now is the time for a post about a technique which demands good sunlight to create some stunning images.

Pond view: 20mm 2.8 nikkor into the sun
Clear sky in the autumn comes very dark and clouds or dust bright reflective
Foliage usually white or pale blue
Lens flare reminiscent of uncoated optics may add interest as not all lens coatings suppress IR flare
No post process

In other words, making what could be an ordinary everyday scene into an extraordinary image - thank you, Guy.


On one of my photography workshops last Autumn/Fall I met Guy and was intrigued by his use of infrared photography using a specially converted camera body.

D200 IR 720 nm conversion by Advanced Camera Systems in Norfolk  ( I also use D50 IR 720 conversion which is good but lacks bracketing etc...). Rather less cheap than just a filter, but full sensor resolution and hand holdable shutter speeds where required. Great way to re-develop and re-use a retired DSLR body, and works very well onto a 6MP APS-C or DX sensor with great actuance at lower res.

Think of it as the contrasty edge of monochrome, or "oligochrome" - palette of only four, black, sepia, turquoise and white depending on chosen target for white balance with high contrast depending on light warmth - sun, filament bulbs and temperature of the material "lit" so sun on cold gives a lot of signal.  There's a lot of fascinating environmental learning to get exposure parameters to than yeild both low and high key images.

Birch copse: 16-85 at 16mm  sidelit just before sunset
Away from the sun minimal flare
Adams-esque approach
Stark contrast between lit and shades improves the textural feel
No post-process


Pseudo colour sepia and turquoise generated by interaction between JPEG parameters, anti-aliasing filter and photosites on the sensor especially in the near infrared (720nm), not seen at 900nm or by using RAW particularly good for textures in sky, stone and wood - skin comes up waxy white which can be quite eerie but good for goth and geisha, most clothing also white or turquoise with a veil like appearance some like this alternate reality not normally seen by humans, some don't, some portrait images look slightly deathly which may startle or shock some viewers.

Some lenses work well for IR (Nikon 20mm f2.8, 16-85mm, 18-70mm, 50mm f1.4, 60mm f2.8 micro   85mm f1.8, Sigma 10mm fisheye for DX)  primes best for sharpness as usual  
and some lenses don't (especially Sigma 10-20 and Tamron 17-50 in my bag) - flare and hotspots of central overexposure and poor contrast you need to experiment, much depends on optical design, use of acrylic elements, coatings.

In IR one tends to see more lens flare as most coatings are designed for visible light, though Zeiss make some IR specific opticals, but even pricier than their usual amazing glassware.

All the usual comments about previsualisation, composition and "get it right in camera" apply as ever but the type of result is so different that some subjects previously dismissed can reveal new content of interest to then venture into a different world of contrast and texture.

Thank you Guy for a wonderful insight into the (once) invisible world of infrared photography.

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