Ultraviolet isn't really my speciality. It's more difficult to shoot (best with quartz lenses) and doesn't really show anything that interesting ... with one notable exception.
Around 100 years ago, Tristán and Michaud investigated flowers in both infrared and ultraviolet. They were working in Costa Rica and published their findings in Scientific American amongst others. They found that while flowers tended to look bland in infrared, at the other end of the spectrum things got more interesting.
On the BBC web site there's a brief clip showing (from a programme called Growing a Planet) Professor Iain Stewart using a modified Nikon with special flash to produce false colour UV shots of flowers. If you've never seen this view of flowers then you should find this insects-eye view fascinating. It's called an insect's-eye simply because research has shown that some insects can detect UV and flowers have evolved to capitalise on that.
More on Tristán and Michaud sometime soon. Stay tuned.
Tuesday, 14 February 2012
Monday, 13 February 2012
Simon Marsden: 1st Dec 1948 - 22 Jan 2012
I'm shaken to have just received an email from Cassie Marsden to say that Simon died on January 22nd. As you know I am an admirer of Simon's infrared work and he contributed to the Infrared 100 exhibition, although we never met.
Our thoughts go out to Cassie and the rest of the family.
Friday, 10 February 2012
BBC Sky at Night on Infrared
The current edition of Sir Patrick Moore's long-running BBCTV astronomy programme, The Sky at Night, is called Age of the Infrared (follow the link for the schedule). The program abstract says:
Space telescopes such as Herschel and Spitzer are peering at the dusty, dark cosmos and with their infrared eyes they can see the cold parts of the sky where stars are being born. Sir Patrick Moore discusses why the infrared is full of hidden delights, whilst Dr Chris North talks to Dr Amy Mainzer about NASA's infrared WISE telescope.Origination is Sunday/Monday at five minutes past midnight (later in Northern Ireland) with several repeats on BBC Two, BBC Four and BBC HD. It will be on the iPlayer as well.
Wednesday, 8 February 2012
More swords and ploughshares
Chris Lavers' Swords into Ploughshares exhibition, looking at the transfer of military technology into civilian life, and including thermal imaging, is running now until March 30th in the Naval Library at Britannia Royal Naval College in Dartmouth, Devon.
Tuesday, 17 January 2012
Thermal video of Concordia shipwreck
Poignant images from the Concordia shipwreck have been released taken with what I assume to a thermal camera mounted on a helicopter. They are described as 'night vision' but I think they are thermal (or composite), with a black and white palette that makes white cold and black warm. You can see the black (warm) passengers and crew making their way down the side of the cold (white) hull.
As you might imagine, the wreck of the Titanic a century ago triggered research into remote detection of icebergs, notably a bolometer with which the horizon can be scanned. Since the bolometer only needs to scan a single defined line it is practical to try and use such a device: a bolometer only detects temperature remotely at a single point. Unfortunately it didn't seem to work, presumably because icebergs are at pretty well the same temperature as the sea and so wouldn't show up with the kind of bolometers available a hundred years ago.
As late as 1934 the American liner Manhattan was fitted with a fog camera, which automatically took an infrared photograph ahead every 50 seconds and then developed and printed it. The hope being that this system would give an early warning of obstacles in haze and fog. The liner's captain reported that the system had indeed been useful in a blizzard and in fog but remarked that it could not be used at night until "ships, lighthouses, and buoys are equipped with infra-red beams". But it was already clear that infrared photography would not penetrate fog and a Times special correspondent, explaining how what could be photographed was dependent on particle size, commented that the Manhattan voyage had "not been suitably foggy for a real test to be made".
Modern thermal imaging cameras are very capable of distinguishing between sea and either objects floating or surface obstructions and the video gives some indication of this. Note that the exposed parts of the ship seem colder (lighter) than the surface of the sea.
As you might imagine, the wreck of the Titanic a century ago triggered research into remote detection of icebergs, notably a bolometer with which the horizon can be scanned. Since the bolometer only needs to scan a single defined line it is practical to try and use such a device: a bolometer only detects temperature remotely at a single point. Unfortunately it didn't seem to work, presumably because icebergs are at pretty well the same temperature as the sea and so wouldn't show up with the kind of bolometers available a hundred years ago.
As late as 1934 the American liner Manhattan was fitted with a fog camera, which automatically took an infrared photograph ahead every 50 seconds and then developed and printed it. The hope being that this system would give an early warning of obstacles in haze and fog. The liner's captain reported that the system had indeed been useful in a blizzard and in fog but remarked that it could not be used at night until "ships, lighthouses, and buoys are equipped with infra-red beams". But it was already clear that infrared photography would not penetrate fog and a Times special correspondent, explaining how what could be photographed was dependent on particle size, commented that the Manhattan voyage had "not been suitably foggy for a real test to be made".
Modern thermal imaging cameras are very capable of distinguishing between sea and either objects floating or surface obstructions and the video gives some indication of this. Note that the exposed parts of the ship seem colder (lighter) than the surface of the sea.
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