Tag Archives: Jon Bowles

Infrared Aerial Photography

A few months ago I bought an IR converted Sony Nex 5N, converted at 665nm. I first got interested in IR after reading about it’s use for photographing bombed targets in World War II; the IR apparently allowing one to see through haze. Since haze has been a perennial problem with my aerial shots, it seemed a good idea to try it. I started with a Pentax *ist DS, converted at 830nm, then traded that in for a K20D, also 830nm.

 

Kunlun Mountains, China. Pentax *ist DS @830nm

    



The problem with these cameras was that they use phase-detection auto-focus, which means focusing is a problem when using zooms. I had both cameras set up to focus at infinity, which is all I need for aerial shots, using the IR marks on my smc Pentax-A 50mm f1.4 and Sigma Super-Wide II 24mm f2.8. These two lenses are both excellent for IR work, but I really wanted to be able to use zooms. I decided to get a Sony Nex 5N, converted at 665nm, which would allow me to add filters (720nm or 830nm) so that I had three frequencies to choose from. It also uses contrast-detection AF, allowing the use of AF zoom lenses. After some teething problems (mainly in setting WB), I was still struggling a bit with the processing, my aim being to get realistic looking colour shots. My first successful image with the new camera was an image of the Labrador coastline, taken with the kit lens. To adjust the WB, I set it in-camera using a piece of white paper, then adjusted it in ACR using a camera profile I created using DNG Profile Editor.

Labrador coast, Sony Nex 5n @665nm

      

 

The image was processed by swapping the red and blue channels, then adjusting reds, yellows, cyans and blues using a Hue/Saturation adjustment on a seperate layer in CC5. However, the more challenging problem of scenes with more colours remained. A few days ago I stumbled across a free free IR faux-colour Photoshop action provided by Khromagery. This has not only cut down my processing time, but gives better results than I was getting with my own home-made action. First results look promising!


Rift valley, Kenya. Nex 5n @665nm




Just for a comparison, here are two shots of the Rift valley taken at the same time, the first a normal colour image taken on my K5, in which the atmospheric haze caused by UV is very apparent, and the second image   an IR shot at 665nm taken on the Nex 5N. The K5 shot has been processed to remove as much haze as possible, the nex 5N processed using Khromagery’s Photoshop action, red, yellows, cyans and blues adjusted in CS5, then a minor final tweak on WB in Lightroom. 

 

K5

 

 

Nex 5N

 

 

 

If anyone would like any more info on how I process my IR images, feel free to contact me. More of my IR images can be seen on my Flickr IR set , and also on here in Galleries.

 

 Meanwhile, keep the blue side up!

 
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