Thursday 7 April 2011

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.