ajkitt
Member 
Posts: 175
What I collect: Classics, Central Europe, World
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Post by ajkitt on May 26, 2018 3:26:25 GMT
Hi all. Does anyone have any information on fluorescence in Germanias? I found a couple 3 mark 1902s (no watermarks) by accident - they happened to be out when I was checking other stamps, and were glowing vividly enough to catch my attention. The brighter of the two was glowing sort of a bluish white, and the other yellow, maybe yellow orange. I have the English version of Michel's Germany Specialized, and the only one they list is from the 1905 series, and it should be red orange.
And, is there any easy (or hard, for that matter...) way to photograph fluorescence? My camera does nothing to capture the colors I see.
Thanks, Andy |
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Post by feebletodix on May 26, 2018 7:03:56 GMT
Good day to you Andy.
Your question caught me by surprise because I was not aware that phosphor was applied on that issue. I pulled out my stockbook and found that where the surface had been worn away the paper slightly flouresced bluish-white on a couple of stamps.
To photograph a uv reaction you need a completely dark room, and a longer exposure. Also make sure you have the correct wavelength uv.
Regards
Gavin
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Ryan
Member
Calgary, Alberta, Canada
Posts: 2,720 
What I collect: If I have a catalogue for it, I collect it. And I have many catalogues ....
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Post by Ryan on May 26, 2018 8:59:11 GMT
Hi all. Does anyone have any information on fluorescence in Germanias? Some older stamps do show fluorescence in their ink even though there was no detection equipment used for automated cancelling anywhere in the world until the early 1960s. Here's a photo nabbed from another board showing fluorescence in early Australian stamps (1c red KGV sidefaces) from around the World War I era. Apparently some ink components used for these colours would naturally fluoresce - it wasn't anything that they were trying to accomplish, it's just what that particular shade of red would do when viewed under UV light. The top 2 stamps here certainly have a big difference in their shade when viewed under UV light, far greater than they would have when viewed under white light.  I don't expect there's any reason for paper of that age to fluoresce, however. I haven't found any paper produced with brighteners in it until the 1950s. Note, however, that soaking stamps for a long time in tap water will often whiten paper appreciably (due to chlorine in the water) and I have also found that stamps soaking against paper with high amounts of brighteners can sometimes be contaminated by that paper. For example, some stamps printed on non-fluorescent paper that are soaked off of envelope cuttings with high amounts of brighteners can change the colour of the stamp's paper when viewed under UV light. Soaking stamps in tap water can brighten them both under UV light and under white light, but stamps contaminated by other paper only seem to be noticeable under UV light. And I agree with Gavin, try photographing in a completely dark room and take your picture with no flash. You need to isolate any white light out of the picture so you are only using the UV light for illumination. I have a guest bathroom with no windows in it and that's where I do my UV light work during daylight hours. At night time I can get a dark enough room just by closing blinds and turning off the lights, but that isn't good enough during the day. Ryan |
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ajkitt
Member
Posts: 175
What I collect: Classics, Central Europe, World
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Post by ajkitt on May 27, 2018 2:21:38 GMT
Hi Ryan, Gavin
The Michel guide does list several early German stamps as fluorescing - it doesn't specify whether it should be the ink or the paper, but, of the few that are supposed to that I have, it seems to be the paper.
I did have a little better luck taking pictures in a darker room, but nothing like the photos posted by Ryan. I'll have to check my camera's manual to see how to extend the shutter duration (or digital emulation thereof). If I get that to work, I'll post what I'm looking at here.
How can I determine the wavelength of my light? I Googled the part/model #and came up with nothing. Is there an optimal wavelength I should be looking for if I have to use a different bulb?
Thanks again, Andy |
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Ryan
Member
Calgary, Alberta, Canada
Posts: 2,720
What I collect: If I have a catalogue for it, I collect it. And I have many catalogues ....
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Post by Ryan on May 27, 2018 4:31:22 GMT
How can I determine the wavelength of my light?
A simple way is to just look at different stamps (assuming you have common run-of-the-mill worldwide stamps). US letter-rate stamps use a type of taggant that fluoresces only with short-wave UV light (high & low face-value stamps often have no tagging, since they aren't used for the same purposes as letter-rate stamps). If your lamp doesn't cause US stamps to glow green (or red for older airmail stamps) then you likely have a long-wave lamp. Canadian general tagged stamps will glow nicely under either wavelength, you'll see the same yellow glow under either wavelength. Ryan |
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ajkitt
Member
Posts: 175
What I collect: Classics, Central Europe, World
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Post by ajkitt on May 29, 2018 3:21:40 GMT
hmmm...so any recommendations on an inexpensive short wave light?
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Ryan
Member
Calgary, Alberta, Canada
Posts: 2,720
What I collect: If I have a catalogue for it, I collect it. And I have many catalogues ....
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Post by Ryan on May 29, 2018 4:30:44 GMT
You can buy small battery-operated UV lights in either wavelength for little outlay. I can't make any recommendations on them, though, as I'm a fan of paper & tagging varieties so I spend lots of time with my UV lamp. I have one of the expensive dual-wavelength Raytech things in a metal case (actually I have two of them, I found a used one once so I snapped it up to make sure I have a working spare). Hooray for tagging varieties!
Ryan
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ajkitt
Member
Posts: 175
What I collect: Classics, Central Europe, World
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Post by ajkitt on May 29, 2018 12:10:29 GMT
I've been looking around online, and apparently rock collectors also make tremendous use of uv - a few long-, mid-, short-wave lights are out there for 50-70$. Is there any real value to the mid-range? Or is that a "try it and find out" kinda thing?
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Ryan
Member
Calgary, Alberta, Canada
Posts: 2,720
What I collect: If I have a catalogue for it, I collect it. And I have many catalogues ....
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Post by Ryan on May 29, 2018 20:09:13 GMT
I've been looking around online, and apparently rock collectors also make tremendous use of uv - a few long-, mid-, short-wave lights are out there for 50-70$. Is there any real value to the mid-range? Or is that a "try it and find out" kinda thing? My UV light came with a usage instruction booklet and it was far more oriented to the mineral collectors than it was to stamp collecting. That was a surprise to me, I didn't know anything about minerals being fluorescent at the time. I've since learned that you can look at colourful tropical fish with UV lights for different markings than what you see in white light, and there was an article popular in the news recently about puffin beaks also being fluorescent! (Kung fu puffins added for reference ...)  Any stamp tagging references I've ever read only detail the use of two different wavelengths, but the type of thing we're talking about here with these ancient inks has more to do with "unintentional" fluorescence. Stamp tagging is intentional and will be specific to the wavelength detection used by the automated facing / cancelling equipment - perhaps there are only two main UV ranges used for that detection equipment, I don't know. It's entirely possible that the "unintentional" UV reactions will include some that have a very narrow range of UV excitation and maybe a third wavelength would turn up something, but it isn't anything I've ever seen mentioned before. Scott Starling is the guru of fluorescence on those old Australian inks and perhaps a careful search through his site (specifically his listings for KGV sidefaces) will turn up something. I was able to find images for perhaps 15 or so of his expertisation certificates and all of them specified the use of a 365nm wavelength (long-wave UV). And just because the odds are that someday somebody might want to know more about some of the chemicals used for fluorescent tagging, and because this is a sensible place to put such info, I found the following snippet which outlines the composition of taggant on US stamps (short-wave UV, not long-wave as with the old Australian ink): "The compounds used were zinc orthosilicate [glows green] for use on ordinary postage, and calcium silicate [glows red] for air mail stamps". Ryan |
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