Laurie Klein: New book and Infrared Photography Course

 The first edition of Laurie and Kyle Klein's book, Infrared Photography: Artistic Techniques for Brilliant Images, came out in 2016 (and was featured here). Now there's a new edition from Amherst Media with extra input from technologist Shelley Vandegrift. I haven't as yet seen the new edition but I like the earlier books so this should be worth consideration.

Info on the book is on this web page.

Laurie and Shelley are also giving a three day "Intensive" course towards the end of September. This will be held using the ubiquitous Zoom running from noon to 1700 (I assume east-coast USA time) and with a course fee of $695. It's aimed at photographers across a range of infrared experience. The middle day will be a practical, where you shoot around your own area with the opportunity for discussion. More info on Laurie's web site.

Photocrowd IR competition

Occasionally photo communities ask for, and sometimes rate, infrared photographs. DP Review have done it in the past and I selected one of their winners for the 2010 Infrared 100 exhibition.

Just launched is one for Photocrowd. If you're a member, or want to join, you can submit photos and rate others. In this case the contest finishes on the 28th. Anyone can view the entries. The ones so far include some interesting ones as well as some strange ones, some of which are (IMHO) not even infrared images! But worth a peruse.

Go to www.photocrowd.com/photo-competitions/infrared-1-technique-photo-contest-5980/.

What colour is the sky in your infrared world?

If you take a digital photograph using a camera which has no infrared-blocking filter, infrared will pass through the colour-filters (the Beyer matrix) on the sensor and will register with the red, green and blue photo sites. With an infrared filter such as the common 720nm one, almost all the radiation reaching the sensor will be invisible to the naked eye. (Saying a filter has a wavelength of 720nm means that at 720mn the filter blocks 50% of the light with shorter wavelengths reduced more and longer ones by less.)

The three colour filters on the sensor will pass near infrared light but in differing amounts and that results in what seems to be a colour picture. I call this faux-colour to distinguish it from the false colour that infrared Ektachrome produced.

It will usually look something like this ...

Here the colour balance has been adjusted slightly to make the foliage appear white/grey but even without this change the sky is a reddish-brown colour.

If you don't like this you can change it since there is no correct version of this colour arrangement, it is purely an artefact of your camera's Beyer filtering when confronted with near-infrared.

The usual technique is to use the colour mixer in Photoshop (or similar) to swap the red and blue channels which results in this ...

There is an alternative way, which is quicker and produces slightly different results. If you convert the image from RGB into LAB colour then you can invert (make negative) the A and B channels to change that reddish sky to a blueish one. Neither of the A or B channels has a red-blue axis. Red-green (A) and yellow-blue (B) are the axes of the components: colours are defined by their position along those two axes (and the L is the luminance or brightness).

Inverting the B channel changes the sky to a blue colour ...

This is different to the channel swap result. Inverting the A channel has a much smaller effect on the image but you can do this as well as inverting B to get this result ...

So now we have three ways to post-process the faux-colour images. My personal preference is for the one with both LAB colour components inverted, but your mileage may differ.

View from the roof

During the 1930s infrared photography was regarded as being one of the wonders of the age. It was featured regularly across the pages of national newspapers, especially The Times, demonstrating its ability to cut through haze and show distant landscapes.

This was brought home to me while perusing a 1938 book called Byways of the BBC which included the photo above, showing the view north from the roof of Broadcasting House towards Regents Park. Including an infrared landscape was clearly quite a reasonable thing to do then. BBC hands will realise that this is before the extension, let alone the current additions, so such a view is probably not available now.

[Feb 21st 2018]

I now find this photograph is also included in the 1932 book the BBC published for the launch of the then new Broadcasting House.

From Wimbledon to the remote Pacific

Two online news stories caught my eye recently.

The BBC web site has a short video montage showing photographs taken by Belgian photographer Sanne de Wilde on the Pacific island of Pingelap. This island is notable because a disproportionate number of the inhabitants are totally colour blind, a condition called achromatopsia. They basically have no functioning cones in their eyes. The cones are what provide us with detailed colour vision, while the rods are more sensitive but only register brightness and at a lower resolution. Our brains combine the two and while we think we see everything in sharp colour, this is not actually the case and only the centre of our vision is actually sharp and colourful. There is another difference between the two parts of our vision, which is that we process the rod images faster than the cone ones. The result of this is that if you look at a bank of TV screens, all showing the same programme, and watch for cuts between shots the screens you are not looking at will seem to cut first.

The colour blindness on Pingelap results from a genetic bottleneck, when most of the population were killed by a tsunami in the 18th century. One of the survivors happened to have the colour blindness and since the population was so small the genetic defect became more prevalent. Neurologist Oliver Sacks wrote about the island in his 1997 book The Island of the Colorblind.

Sanne de Wilde has also produced a book with this title but in her case she has uses faux-colour infrared photography as a way of looking at the islanders' condition and has produced some striking images. A 10 minute film was also shown at the 2016 Tribeca Film Festival and a book is available (which has a UV-sensitive cover!). Check out the web site at www.sannedewilde.com and those of the book's publishers, Kehrer Verlag and Uitgeverij Kanibaal.

You probably know that Wimbledon fortnight has just finished and, with it, the 2017 tennis championships. The Guardian's sports photographer, Tom Jenkins, decided to take some faux-colour infrared shots at the championships and you can see the results on this web page. My only niggle is that whoever wrote the captions is confused between near-infrared and thermal imaging because these photographs are not thermal images and do not show heat. Nevertheless they are fascinating, partly because Tom has sometimes used selective focus to increase the otherworldliness of the scenes, making them take on the appearance of models.

Biggles shoots infrared photographs over Mount Everest

There has been news coverage recently of the digitisation and publication of films from the archive of the Royal Geographical Society, and BBC reporter Pallab Ghosh narrated a film on the BBC News channel about some of them. One such film comes within our purview, being a record of the 1933 Houston Expedition which flew biplanes over the Everest range. They shot movie footage and stills, including some infrared plates provided by Olaf Bloch at Ilford.

In the early 1930s, infrared photography was something of a popular sensation and from about 1932 newspapers regularly printed large IR photographs demonstrating the ability to penetrate atmospheric haze and achieve extremely long distance views.

Everest summit and Chamlang taken from 100 miles away

The published book documenting the expedition, 'First over Everest', goes into some detail about the infrared setup. Plates came from Ilford, and by this time the sensitivity of infrared plates was such as to allow exposures 'as rapid as one-sixtieth' of a second. Taylor, Taylor & Hobson loaned a lens with an aperture of 4.5 and a focal length of 25 inches (635mm). The camera 'was a somewhat rough and ready improvisation made of plywood' which was sourced with the help of The Times newspaper and its legendary art editor Ulric Van den Bogaerde (father of actor Dirk Bogarde). There was, presumably, a quid pro quo because the Times had first publication of images from the expedition. On May 8th 1933, almost exactly a month after the flight, the Times was able to publish the expedition's most famous photograph, showing the summit of Makalu, the fifth-highest mountain in the world and 22 km east of Mount Everest itself, rising above cloud from a distance of over 100 miles.

The camera was very big and heavy and required special mounting in the plane. It was three feet long by a foot square and was placed under the fuselage, hanging in vibration-proof mountings where this aircraft was designed to carry torpedoes, and set up pointing forwards so that the field of view did not include the bottom cylinder of the engine. Plates were changed through a hatchway in the floor of the observer's cockpit. The observer had to hang upside down and put his head and hands through the floor to reach the rear frame of the camera and so access the wooden double half-plate dark slide ... hoping that the wind didn't whip it out of his hands. From this position the camera shutter could be operated. Lining up the shot involved either using the plane's intercom or, if necessary, writing notes. The cue between pilot and observer to take the shot was done using a piece of string. A sharp tug telling to pilot to line up and fly right, with a reverse pull giving the cue to fire the shutter.

The size and weight of the infrared camera were such that it couldn't be fitted to the aircraft for the high altitude flights, so infrared photographs were taken on subsidiary flights, after the main sorties had been completed. There was the added problem that, being outside the fuselage, the camera and lens would have frozen up at the higher altitude. Electric heaters were used for both men and equipment (these were open cockpits) but heating an external camera would have taken too much current.

Even though it doesn't mention the infrared work, the 1934 documentary film of the expedition, which won an Oscar that year, was called 'Wings over Everest' and is well worth a look. It's available to view freely on the BFI web site. There is a definite 'Boys Own' feel about the whole affair, and the BBC described observer Major Latham Valentine Stewart Blacker as being a real life Biggles. While some of the documentary was re-enacted in a typically 1930s way that we now see as being wooden, the real people are featured. But the expedition was filmed as it happened, including aerial footage shot from the cockpit which is a combination of shots from three of the flights.

Two final notes: the expedition was named after Lady Lucy Houston (pronounced How-sten), who provided funds and was quite a character herself (check out the Wikipedia entry on her) and, as the BFI points out, the while thing was inspired by novelist John Buchan.

Professor Wood's slides

This is a tale I have been waiting to tell for a while.

Regular readers will know that in 1910 Professor Robert Williams Wood, of Johns Hopkins University in Baltimore USA, published an infrared landscape photograph. The Midwinter Number of the Century Illustrated Monthly Magazine, priced at 35 cents, appeared in February 1910. In this was an article by Wood called A New Departure in Photography, which included an infrared photograph of his summer home in East Hampton. As far as I know this was the first infrared photograph (as distinct from a spectrograph) to be published. Later that year Wood presented his seminal paper on photography by Invisible Rays to the RPS in London and then went off to Italy. While in Italy he took more infrared photographs, many of which were published in the Illustrated London News in June 1911.

I had thought that Wood's actual photographs from this time were lost, despite the set from his RPS lecture being made available for hire from famous slide dealers Newton of Museum Street, London. So the ILN printed versions were the only ones available.

Surprisingly I came across a web page from Chris Fastie. His late father was a contemporary of Wood's at Johns Hopkins and had been given some slides, large format 'lantern' slides, of Wood's infrared photographs. These included some from the Italian trip, but also included one labelled 'First infra-red photograph' which showed another view of the East Hampton house.

The label on the slide of the East Hampton photo (above) is interesting:

So this claims to be the first infrared photograph; different from the first one published. There isn't a date on it unless that is part of the missing text (could that be revealed under infrared light I wonder). Wood's biography refers to the first photograph being of 'distant hazy' mountains taken in 1908 but this would seem to be a label, probably written by Wood himself, contradicting that. Definitive?

You can read a more detailed account on Chris's web page here.

The house was (and apparently still is) on Apaquogue Road and he was famous enough for there to have been a postcard produced, early in the 20th century, showing the 'Home of Prof RW Wood, East Hampton LI'. You can see it here, as part of a book of old postcards of East Hampton by Richard Barons and Isabel Carmichael and from the collection of the East Hampton Historical Society.

At this time I contacted Professor Paul Feldman at Johns Hopkins (he took part in our symposium in London back in 2010) and told him about this discovery. It turns out that Chris Fastie's father Bill was Paul's mentor at JHU and they all know each other. Then, Paul decided to take a look in what he called 'the attic' in the Physics department and found some more slides. These look to be others from the same set but,as they don't include the 'moon cave' image published in the ILN, it is possible there are more out there.

[My thanks to Chris Fastie and Paul Feldman for sending me scans of their discoveries]

Infrared forensics

Infrared imaging has applications in forensics. Sometimes this is because an infrared image can show variations in an object that are otherwise invisible (which applies to UV as well of course), sometimes because changes in the appearance of something under IR can show up a surface artefact, such as a fingerprint. I'm sure there are more, but I have much to learn in this area.

A recent email alerted me to a somewhat sideways use of IR in forensics, where photographer Robert Schults spent a year documenting work at the Forensic Anthropology Center at Texas State University. This seems to be basically Bones meets Silent Witness, including a 'body farm', where decomposition is studied. Robert used infrared photography in this project.

Jayme Blaschke, who emailed and works at the university, worked with Shults for more than a year on this project, along with the staff of the center. He tells me that the camera was a Leica converted with an 830nm filter (Jayme's recommendation ... good call).

You can read more in a New York Times blog piece on the project, called Photographing the Science of Death and Decay. Robert Shults' own web site is www.robertshultsphoto.com. Wired have a story with a fascinating set of images as well ... scroll down for the text. (They mention an IR converted Fujiflim X-Pro 1.)

[Image from National Institute of Standards and Technology (NIST)]

Laurie Klein Artistic Techniques Book

Following on rapidly from her excellent book Photographing the Female Form with Digital Infrared, Laurie Klein has joined forces with her son Kyle for a more general coverage of infrared photography.

Basically (and simplifying somewhat) Kyle discusses the subject from a technical perspective while Laurie discusses the art and technique. As I noted in the review for Female Form, Laurie studied with Ansel Adams and his fingerprints can occasionally be found in her work. This book even mentions the Zone system, in the context of using the camera's histogram display. For infrared photography, where the captured images often have a restricted palette, the histogram is even more useful than in conventional photography.

There's a lot to glean from this book. Personally I find more to learn in Laurie's contributions but that's not to denigrate what Kyle wrote, just where I'm coming from with my research into the subject. What I really like is that post-processing, which is undoubtedly an essential part of digital IR, is placed in a reasonable perspective. The book leads you through the workflow of making the image with the camera and then adjusting it to match the vision. I'm particularly interested in the section on emulating the old Kodak film halation and will be exploring that before long.

Infrared Photography: Artistic Techniques for Brilliant Images by Laurie Klein and Kyle Klein is published at $37.95 by Amherst Media. I note that Amherst have really upped their game with the printing in their recent books: no complaints on that score. The format fits the usual Amherst US-Letter size, perfect bound.

I've also been sent a copy of Karen Dórame's Mastering Infrared Photography by Amherst, which I'll be looking at before long.

Infrared rainbows

It was Robert Greenler who, having deduced that there should be an infrared component to a terrestrial rainbow, finally succeeded in photographing a natural one in 1970. I've had a go myself and if the sky does what you need and the camera is steady enough it is not too difficult to give it a go yourself.

Scientific American recently published an article entitles Think You Know Rainbows? Look Again, which discussed and showed examples of rainbows that were not particularly rainbow coloured, including a white one and a red one.

The red example in the article (reproduced above) was taken from the Wikimedia Commons, and was taken by Jason Campbell in 2011. The cause, as the article explains, is that the light source is a setting sun and at this point only red light was available to be refracted by water droplets to form the bow.

You probably see where I'm going here. Let's assume that near-IR is also in the sunlight as the sun sets and that this remains a little after the red has gone. In this case it should be possible for an infrared-only rainbow to exist.

Presumably anyone with a suitable light source and some fine mist could produce one in the lab but has anyone managed to take a photograph of such a thing 'in the wild'?

[As an aside, I recently saw that the light from a rainbow is polarised along the circumference of the bow. Obvious when you think about it but I'd never noticed before.]

New Books for a New Year

I've been notified of three photographic books that may be of interest, coming out over the next few weeks (or May in one case).

Ed Thompson's The Unseen: An Atlas of Infrared Plates has a May 2016 publication date from Schilt Publishing and a cost of €45. More information on their web site.

I love the idea that this is somehow an old-fashioned atlas of hitherto unknown territory ... down the spectrum with gun and camera (without the gun) in the manner of a Victorian explorer. One thing I would take issue with is the publisher's quote that "Thompson has created a swan song to the medium of infrared photography" since the technique is alive and well. What this is a swan song to is infrared film of course, and especially the false-colour infrared film that Kodak used to produce, and of which Ed is an accomplished exponent.

I've mentioned Laurie Klein, and her book Photographing the Female Form with Digital Infrared, before. Her follow-up is almost with us, co-written with her son Kyle Klein, and published by Amherst on January 12th 2016 at $37.95 (list).

I haven't seen the book on paper as yet, but there's a comprehensive preview on Amazon and it will also be available from other stores who stock Amherst's books..

Finally, a quick note to say that Elliott Landy's Kickstarted book of The Band Photographs (Big Pink etc) is now available in various enhanced formats from his web site ... and going fast ... (there's a preview there as well as on Amazon) and from book stores. Prices range from $45 to $500 and Elliott's web site is offering the first edition print of the book. I mention this because, although they are in a minority, there is a section of infrared photos amongst this set. I wrote more about this almost exactly a year ago.

October odds and ends

A couple of items for your interest.

Shutterbug published a lovely appreciation of Sir Simon Marsden on October 5th. I also found him very communicative and helpful at the time of the Centenary and really regret not meeting up, especially now I live a lot closer than I did in 2010. This has prompted me so that this year I've decided to desert Ansel Adams and get my 2016 calendar from the Marsden online shop.

Rather oddly, considering the piece dates back to August 2014, New Scientist just tweeted a link to an edition of their 'Last Word' column, which asks 'How far beyond the visible spectrum does a rainbow extend?'. The responses discuss both UV and IR extensions of what we see, and especially how those might be more dominant on other worlds such as Titan. It reminds me of the work of Robert Greenler who, having deduced that there should be an infrared component to a terrestrial rainbow, finally succeeded in photographic a natural one in 1970.

I recently had a visit from Ed Thompson and had a sneak preview of his upcoming book of colour infrared photographs. I'll write more about this when it's published but suffice to say there's lots of red and a delightful conceit in the way the book is packaged. In the meantime if you're in the vicinity of the Rough Print Gallery (14 Bradbury Street, Dalston in London) then images from the Red Forest and The Village portions of his epic Unseen project will be on show. The gallery Tumblr stream tells us that it's part of the White Rabbit Restaurant and the gallery is open 10-5 Wednesday/Thursday and during the restaurant opening hours. Starts 15th October and runs to the 21st.

I think that'll do for the moment.

Ed Thompson @ Photo-Forum

Ed Thompson will be talking about his series of colour infrared photographs - Unseen - at a Photo-Forum event in London on May 14th. His talk is alongside one by Lewis Bush, another photographer with an unique vision.

I wrote about Unseen last month: here and here.

The Photo-Forum event is being held at Calumet in Drummond Street, starting at 1800, and you can find out more on the Photo-Forum web page.

[Always happy to help promote exhibitions and talks involving infrared imaging: just drop me a line]

The physics of near-infrared photography

Klaus Mangold (a photographer), Joseph A Shaw and Michael Vollmer (who are physicists) have just published a paper, The physics of near-infrared photography in the European Journal of Physics. This is the best technical paper on the subject that I've seen since Clark's book Photography by Infrared (which went out of print in 1984).

The European Journal of Physics has a policy of making papers freely available for 30 days from publication, although you will need to set up an online account to access it.

Amongst other things the paper tells us that red wine, Diet Coke and even espresso coffee are transparent to near-infrared wavelengths.

This is the URL: stacks.iop.org/EJP/34/S51

The citation is Eur. J. Phys. 34 (2013) S51–S71

DSLR infrared sensor response

Camera manufacturers tend to be coy about releasing the spectral response of their sensors: they're (logically) more concerned about how the camera as a whole performs than how the sensor might deal with infrared (or UV).

A peek behind that curtain has come courtesy of Christian Mauer of the University of Applied Sciences in Cologne. His thesis Measurement of the spectral response of digital cameras with a set of interference filters (January 2009) is interesting in its own right but if you work your way down to Appendix A page 81 (section A.1.7) you will find the spectral response of a Canon EOS 450D without its IR blocking filter. It shows the usual bump in blue response just beyond 650 nm so that the respective responses of the red, green and blue channels at 800 nm are around 20%, 30% and 40% of the peak green response (at 540 nm) respectively. All channels come together at 20% at 850 nm and the response is monochromatic beyond that.

These figures are actually showing the spectral response of the sensor plus its Beyer filtering, since the underlying sensor is monochromatic and should have a smooth response curve peaking at around 600 nm and slowly dying away to over 1000 nm. However, this explains the strange colours when you take infrared images through a 720 nm filter and why ones through an 850 nm or longer filter are colourless.

60 megapixels of near-infrared

Back in April, I wrote about the Leaf Credo wide spectrum backs which had been set up to shoot near infrared out of the box at resolutions up to 80 megapixels. Yair Shahar (from Leaf) and I spent a couple of hours on Primrose Hill in London trying the 60 megapixel version out with both a Mamiya body and a technical camera.

The image as shot with the 60 mp back is an extraordinary 8984 by 6732 pixels. With a suitable lens the resolution is also impressive, giving scope for huge detailed prints. To give you an idea, here is a 6200 by 4000 crop from a shot through a 950 nm filter looking south from Primrose hill directly towards the Shard.

If I zoom in on this until you're looking at it pixel for pixel, this is what you see just to the left of centre on the horizon, between the two dark buildings to the left of the Shard.

This was with a Mamiya 80m lens (half a second at f9, ISO 50). With a technical camera lens the image was even sharper. I have found that infrared can produce very interesting cloud images even on an overcast day, presumably because of a different balance between the brightness of the ground/trees (which show up bright in infrared due to the Wood Effect) and the cloud base. You can focus using live view with this back, which is pretty well essential for such a shot, as is a tripod. The back has no anti-aliasing filter. In general you don't need one for landscapes although there was one distant building in the scene we shot that exhibited some moiré, which was easily removed/disguised.

Leaf use another of our shots from that test on their guidelines brochure.

I had hoped to be able to do more infrared tests with the Credo during July but, unfortunately, it wasn't possible due to my work load. But the main point is made by the brief trip to the top of Primrose Hill, which is that you can produce dramatic landscapes with this kit. I'd love to see what a real landscape photographer could come up with, given more time and better weather. The Credo WS back is also proving of interest in art conservation and for forensics. There is a lot to be said for the 'shoot first and examine later' ability of very high resolution images.

[My thanks to Leaf and Yair Shahar for their help with this test.]

Russia: A World Apart (Simon Marsden and Duncan McLaren)

It's very sad that Simon Marsden's refrigerated and dwindling stock of Kodak HIE outlasted him. He was, to my mind, the finest and most consistent user of that idiosyncratic film stock with its haloed highlights and exaggerated grain. That's not to understate his abilities in the darkroom, but it's the classic HIE look that I will remember him by.

With its distinctive look, many people have thought of infrared film as showing something supernatural. When he loaned us a print of Moydrum Castle for the Infrared 100 exhibition, Simon wrote to me saying ...

The goal of my work has essentially always been the same: to demonstrate that magic is real or that reality is magic. I have used infrared film for its ethereal quality, day is turned into night and nothing in this twilight world is quite as it seems. The unusual texture of the film's grain produces a timeless feature that lies somewhere between an etching and a photograph.

The trail that began with ruined Irish castles has finished with an eerie collection of Russian landscapes in the book Russia: A World Apart. Some are unkempt ruins, which always lend themselves to the increased contrast that infrared brings. I sometimes think that our ruins here in England are too neat: should a derelict monastery be set in manicured grounds? Not all the places visited are ruined: the Winter Palace in St Petersberg is not, but stands under a brooding cloudy sky while the sun fails to break out from behind the Alexander Column. Backlighting is another hallmark of much of Simon's work.

Chernyshev Estate, Yaroplets, Moscow Region

I should not forget the text. Duncan McLaren, who collaborated on those Irish Ruins (indeed he instigated that first project) and a post-USSR venture beyond 'the wall', accompanies the photographs and photographer again. He tells the stories of not only the artefacts' past but often what is happening now; the people he and Simon met on their journey.

Russia: A World Apart is an atmospheric book; in keeping with the best of Simon Marsden's work. Infrared photography is a genre that you either love or just don't get. This book demonstrates one aspect of it at its best.

[Published by Mudds & Stoke at £25 ISBN 978-0-9573795-0-3]

AP Award for Simon Marsden

I know this isn't a news site but - a trifle belatedly - I can report that Amateur Photographer acknowledged the late Simon Marsden for Exceptional Achievement in Photography in their 2013 awards. I can add that successfully publishing book after book of infrared photographs is an achievement in itself and his contribution to the technique will be (is already being) sorely missed.

As usual, a pointer to the Simon Marsden web site and a note that a new book, Russia: A World Apart by Simon Marsden and Duncan Mclaren, will be published on May 9th 2013.

Emulating infrared Ektachrome

The false colour infrared Ektachrome (or Aerochrome) can be emulated with a digital camera. I had noticed, when researching my history of infrared photography, that early digital cameras did include infrared models.

The AP NC series, introduced by Kodak in conjunction with Associated Press in 1994, included an infrared monochrome model, the AP NC2000ir with a resolution of 1012 by 1268 pixels. The DCS 420 and 460 series, introduced in 1995, also included infrared but this time included colour models. The 1999 DSC 6XX series also included an infrared configuration. However, with the basic colour units selling for between ten and twenty thousand dollars, and the infrared versions being special orders on top of that, these were not exactly consumer cameras. The colour infrared cameras, such as the DCS 420, were simply colour digital cameras with the kind of Beyer tri-colour filtering that is still standard, but with the infrared-blocking filter removed.

The aim was to reproduce the false colour abilities of Kodak's EIR infrared Ektachrome and this could be achieved by putting a minus-blue filter in front of the lens. The blue channel then only contained infrared information and the red and green channels contained their colour plus some infrared 'leakage'. By calibrating the system and subtracting appropriate amounts of the blue channel from the other two a result similar to EIR could be achieved.

I'd tried this before, using a borrowed Canon but on a somewhat overcast day. Using my FujuFilm IS-Pro I've shot some more tests, such as the image above, of Eashing Bridge. That's how the raw image looked after each channel had been normalised (ie the darkest and lightest points set).

Using the Photoshop channel mixer, the red output channel is set to the blue input, green output is set to red input and blue output is set to green input. Remember the yellow filter will have removed any real blue from the image. Next some of the blue input channel (which is really the infrared) needs to be subtracted from the green and blue outputs. This is not scientific and is certainly uncalibrated but in this case subtracting 50% blue from the blue output and 65% of blue from the green output gave a suitable colour balance. I also played around with gamma and curves to improve the look of the image: as I said, it's not scientific.

This is the result:

Matson infrared photographs

An interesting and unexpected source of infrared photographs from the 1930s is the American Colony in Jerusalem, later the Matson Photo Service. According to the Library of Congress, where the collection [infrared photographs | whole collection] is now kept, the colony was “an independent, utopian, Christian sect formed by religious pilgrims who emigrated to Jerusalem from the United States and Sweden. The history of the Colony is intimately linked to the photography collection it spawned.” Eric and Edith Matson continued the photographic work in the middle-East and around east Africa after the colony broke up in 1934. They were innovative photographers working with infrared, colour, 3D and aerial photography although most of the collection is conventional.

This is one of the infrared plates in the collection, entitled Haifa, looking across the bay from Carmel showing harbour & Acre beyond. It's a 5 by 7 inch dry glass plate, which begs the question of where this was sourced. Given the climate in what is now Israel my guess is that the plate was sensitised locally.

More detailed information on the colony and the collection can be found on this LOC page. There are thousands of fascinating images in the whole collection and many of them can be seen online. You can find a few more infrared photos by searching using infra-red but this also hits a lot of false drops since the term appears in a general descriptive field (hover over the thumbnails of the first few photos to check titles for the word infra-red). I should also add that there are photos taken around Africa as well as in what is now Israel.