Tristán and Michaud

In a letter to the Times, dated June 4th 1932, CEK Mees referred to long-distance infrared photographs of mountains, taken in Costa Rica in 1915 or 16 by Gustave Michaud and J Fidel Tristán of Costa Rica State College, which were published in Scientific American. I've been trying to track down more information about them, and it seems they were pioneers in both infrared and ultraviolet photography.

Unfortunately I have been unable to find the Scientific American article to which Mees refers. Scanning through the bound volumes for 1915 and 1916 in the British Library did not reveal them. However I did find a few relevant items there and on the web.

They wrote an article on Flowers photographed by invisible light in the October 10th 1914 edition of Scientific American. Most of this demonstrated how many white flowers came out 'black' when photographed under ultraviolet light, or showed some patterning that was not apparent in ordinary light. They did comment on how flowers looked in infrared but as they usually showed up as 'white' they didn't find this as interesting.

I have photographed flowers, even dark ones, in infrared. This is an example. It is actually a dark red rose, illuminated by a flash gun.

An unusual reference to their work appears online in a 1918 edition of a magazine called Rays from the True Cross (see page 209) in an article called Insects that see 'Invisible' Light, which tells us that in an edition of Scientific American dated Jan 15 they were again investigating the appearance of flowers, which

led us recently to photograph, in ultra-violet and infra-red lights, a number of butterflies

This article was not in any Scientific American in 1915 but the date may well refer to January 15th, possibly in 1918 ... but I have not had a chance to track that down as yet.

A further piece of research was published in Archives des sciences, March 1915 into absorption of UV and IR by arable soil and included both kinds of photographs.

It is remarkable that only a few years after Wood demonstrated that the world could look different in infrared (and UV) that these two researchers used photography to investigate aspects of this in detail. I would like to find out more about these two. Anyone know anything more?

[FYI: A useful resource of Scientific American for this period can be found at www.scientificamericanpast.com.]

Olaf Bloch's 1930s lectures

In the early 1930s Olaf Bloch was the president of the RPS. He was also chief chemist of Ilford's laboratory, and I was already aware of a paper he presented early in 1933 to the Royal Society of Arts called Recent Developments in Infra-red Photography. During that presentation he took an infrared photograph of the audience which was projected later. The RSA journal does not include the photograph.

I recently got hold of a copy of the RPS Photographic Journal for August 1932, knowing it included an article on infrared. I had hoped that, given the date, it would give me some more information on the infrared plates that became available during 1932 from Kodak and Ilford. That wasn't the case. Instead the RPS paper was an earlier appearance of Bloch's presentation, actually given in April 1932 and hence a little early for my historic purpose.

However, despite this lecture being given unexpectedly because the planned showing of various new pieces of equipment wasn't possible, Bloch performed his 'party piece' with an infrared photograph of the audience. This is it.

I don't think this was taken in complete darkness but I would expect the normal room illumination was low and lamps with infrared filters were set up for the purpose. The published paper also included a long-distance infrared photo of the Isle of Arran that was published in the Times on May 30th 1932.

Is there or is there not an infrared Olympus Pen?

Further to my note about a infrared version of the Olympus EP1 being seen at a show, we have tried to get some further information from Olympus about this and, sadly, we got nowhere. This probably means that yes, there is one ... but there is only one and it's not a product.

You can guess my feelings about manufacturers missing a trick with the potential market for well-configured infrared cameras.

Further back on the Wood Effect

In a post in December last year I wrote about the Wood Effect, which causes foliage to look white in infrared photographs. I had traced the term back to a reference to an article in a journal called Photofreund published in Germany in 1938, which I had not seen.

Now, with help from a friend in Germany, I have been able to read the article. (Bearing in mind I don't speak German so this was achieved with some assistance.)

The paper is called Warum erscheint gruner Pflanzenwuchs bei Infrarot-Aufnamed weiss? This translates as Why do green plants appear white on infrared-photography? and one paragraph (translated) reads

In that kind of pictures it is extremely disturbing when all plants appear in an unnatural bright tone, as if covered with white frost or snow. Where does this so-called "Wood-effect" (1910) come from?

This doesn't actually resolve my search, since Dr Marmet, the author, refers to the Wood Effekt as bezeichnete, literally designated according to my dictionary. This implies that the term was already in use and Dr Marmet had heard it elsewhere, but whether in a German or an English language publication is unclear. He includes the 1910 date as well but doesn't say to what he refers: this could be the RPS Journal or Century Magazine. Remember that Mecke and Baldwin, writing in 1937, were calling it the Chlorophylleffekt.

The difficulty with online searches for wood effect is that you keep coming back to timber! But I shall keep digging.