Top of the World with Albert W Stevens

This week's breathtaking freefall from 128 thousand feet by Felix Baumgartner has reminded me of another high-flying pioneer who also plays his part in the history of infrared photography.

Up to 1956 the record for a balloon ascent was held by Albert William Stevens and Orvil Arson Anderson of the Army Air Corps who reached 72,395 feet on November 11 1935 in their sealed gondola named Explorer II. They launched from South Dakota with millions listening on live radio. [Pathé newsreel coverage here.] Stevens and Anderson, together with William Kepner, had made a previous attempt, 1934 in Explorer I over Nebraska, but the balloon burst and the intrepid trio had to parachute to safety from the plunging gondola. There's a good piece about Stevens and the preparations for this ascent in the March 17 1934 Literary Digest. You'll note the photograph of him and a huge aerial camera, for Stevens was an accomplished aerial photographer.

Many of his photos were taken on infrared film, to combat the problems caused by haze when photographing from altitude. He took the first photograph to show the curvature of the earth and he photographed the shadow of the moon on the earth during the 1932 solar eclipse over the US. His images from Explorer II included the highest photograph ever made (a record that also stood until the 1950s) and covering the largest area ever taken with a single lens, showing a horizon around 330 miles away. (The specification was 1/25th second using a Fairchild F4 camera with a Kodak 304mm f5 lens on Eastman infrared Aero film through a red filter.) This wasn't the longest distance Stevens managed to photograph. His 1933 aerial photograph of Mount Shasta in California was taken from a plane flying at 23 thousand feet from a distance of 331.2 miles. The atmospheric haze rendered the mountain invisible, so the camera was oriented using a compass. The Mount Shasta photograph, courtesy of the Kodak Archive in Rochester, was included in the Infrared 100 exhibition.

Stevens's adventures were usually undertaken with the help of the National Geographic Society and stories of his exploits and many of his photographs can be found in editions of that journal from the first half of the 1930s. The Explorer II gondola is now in the US National Air and Space Museum.

... and now the Marsden calendar

If you fancy a 2013 calendar of infrared photographs ... and sorry but I don't do one .. you should look at a collection of superb infrared photos in the latest edition from Simon Marsden's archive.

Available from the Marsden web site. Even if you don't fancy the calendar you should look at the photos: all taken on Kodak HIE from Simon's private refrigerated stash.

Nikon Owner article on Simon Marsden

The latest issue of Nikon Owner features Simon Marsden and his atmospheric 'ghosthunter' images, often taken using Kodak infrared film. Gray Levett's article The Dark Knight Rises: Sir Simon Marsden is also available as a PDF on the Marsden Archive web site.

Simon's photos are well worth studying if you're into infrared photography. His technique of shooting into the sun with buildings usually silhouetted and haloed as a result is an interesting alternative to the bright foliage we usually strive for. It took me a long time to get what he was doing.

Simon was very helpful with the RPS infrared centenary in 2010 and I am really sorry that we never got the chance to meet.

Flaming exhaust

Thermal imaging makes it easy to see hot gases and this is clearly visible in part of the video in this BBC new story.

A stolen car is shown driving along a slip road on the M6 motorway, turning around to go back up the slip road (the wrong way) to avoid a trap and then turning back onto the motorway at speed. The exhaust gases from the car can clearly be seen as it speeds away. The wheels can also be seen 'white' (ie hot) and there are tails behind the car which could be either camera lag or heat left on the road by the tyres.

Filter experiments: blue

It's taken me a while to get around to doing some serious experimentation with my FujiFilm IS-Pro. This is basically a FujiFilm S5 with the infrared blocking filter removed and while, when released, it was ludicrously expensive the price came down to clear stock. As far as I know it was the only commercially available infrared-capable DSLR since the early Kodaks.

With an SLR the difficulty when photographing using infrared film was being able to see through the viewfinder. Of course you could use a tripod but this wasn't always an option. Most of the time I used a deep red (#25) filter, which gave a good Wood effect but could still be seen through, albeit dimly. The problem continues with a DSLR, especially if you don't have a live view mode.

I thought I'd try filtration alternatives with the DSLR - red, yellow (minus-blue) and blue - as alternatives to opaque infrared-pass filters such as the Hoya R72. The plan was to be able to see through the lens while making the most of the sensor resolution, which means always using the green channel as it has twice the pixels of the others in the Bayer matrix. Of course the Bayer processing mixes things up quite a bit and in an ideal world I'd write my own RAW decoder ... but perhaps that's for later.

I took the opportunity of a holiday in southern Spain ... with lots of sun and plenty of foliage ... to try out using a blue filter, a #47 colour-separation filter made by Tiffen. The light path is like this ...

... because the blue filter does pass a significant amount of near-infrared. I think all blue filters do but I can only vouch for the Tiffen.

Initial experimentation suggested that setting the camera's auto-exposure to -3 or -4 EV brought the histogram into the centre for all channels and the autofocus would work. I could also shoot at f8 and ISO 100 since there was plenty of 'light' available. The lens I used was a Nikkor 18-200 mm f/3.5-5.6 zoom which appears completely immune to the notorious hot-spot.

This is the result straight out of the camera (apart from some desaturation of the blue channel).

The colour palette isn't as broad as the one you get using an R72 (less greens) but I thought it quite pleasant. And what about the green channel on its own for that pure infrared look?

Pretty promising I think.