dbooksta Posted February 14, 2016 Share Posted February 14, 2016 I was wondering if very strong infrared light would be effective at blinding digital cameras, which are sensitive to near-infrared light (<1000nm wavelength) but which often have strong filters for wavelengths just beyond visible red. So naturally I'm wondering if there are any pyrotechnic compounds that could produce a strong infrared flare for testing this out. So does anyone know of elements or other compounds that are efficient light-producers in the 700-850nm range? Link to comment Share on other sites More sharing options...
Fulmen Posted February 14, 2016 Share Posted February 14, 2016 Yes, do a search for IR tracer compositions. Seems like boron is the fuel of choice, although I'm sure there are other alternatives. Link to comment Share on other sites More sharing options...
felixthecat Posted February 14, 2016 Share Posted February 14, 2016 im shure ive read somewhere that magnesium and ptfe flares produce a lot of infra red and are used in heat seeking missile decoys Link to comment Share on other sites More sharing options...
Fulmen Posted February 14, 2016 Share Posted February 14, 2016 If visible light isn't a problem your have more options, anything white will produce copious amounts of IR as well. Link to comment Share on other sites More sharing options...
Arthur Posted February 15, 2016 Share Posted February 15, 2016 Looking for a reaction that gives you spectral lines in the near infra red will be hard, but there will have been theoretical work done on the chemistry somewhere sometime. Just that for a hobbyist the infra red spectral analysis could be difficult. Link to comment Share on other sites More sharing options...
lloyd Posted February 15, 2016 Share Posted February 15, 2016 Get thee a copy of Shidlovsky, Principles of Pyrotechnics. Lloyd Link to comment Share on other sites More sharing options...
dbooksta Posted February 15, 2016 Author Share Posted February 15, 2016 Looking for a reaction that gives you spectral lines in the near infra red will be hard, but there will have been theoretical work done on the chemistry somewhere sometime. Just that for a hobbyist the infra red spectral analysis could be difficult. Yeah this is the hang-up: Visible spectral lines are easy to find. I haven't found a single source with data on the broader spectrum, but for elements and simple organic compounds I know the data have to exist for astronomical reference if nothing else. Actually I'll post the question on an astronomy forum and see if that yields any clues. Lloyd: I'm not expecting to find more than a footnote on near-infrared output in any conventional pyrotechnic reference. Just not as dazzling as visible wavelengths Link to comment Share on other sites More sharing options...
lloyd Posted February 15, 2016 Share Posted February 15, 2016 (edited) Shidlovsky, a conventional pyrotechnic reference? Yep... it's all about how to make sparklers and illegal firecrackers -- That's the one! (It was translated from Russian to English by our US Air Force because of its content. I suspect they're not really into "conventional pyrotechnic reference(s)", either.) There are at least half a dozen good military pyrotechnics tomes out there being sold in the 'greater pyrotechnic genre'. But since you already know the formulae and treatises within them... (Even "The Wizard's Formulary", which is directly targeted to fireworkers, contains five infrared-specific flare formulae...sigh...) LLoyd Edited February 15, 2016 by lloyd Link to comment Share on other sites More sharing options...
dbooksta Posted February 15, 2016 Author Share Posted February 15, 2016 Lloyd -- forgive my assumption. I'll go back through my existing books and also try to get a copy of Shidlovsky's. Meanwhile, I was pointed to this cool NIST site which has extended spectral data. Boron, for example, does have a line at 783nm, but it's less than half the brightness of several lines in the visible spectrum. Link to comment Share on other sites More sharing options...
lloyd Posted February 15, 2016 Share Posted February 15, 2016 FWIW, Shidlovsky doesn't expressly list infrared flares in its available formulae, but it does discuss the impact of various materials on the emitted wavelengths and strengths. Boron and boron compounds are often used in IR devices, expressly because of that strong 783nm line. To raise the 'effective luminosity' of a pyrotechnic flare, you increase it's burning surface area. So... a perfectly spherical comet/star that required to be twice as bright as it is, would only require to be 1.414X larger in diameter. Lloyd Link to comment Share on other sites More sharing options...
dbooksta Posted February 15, 2016 Author Share Posted February 15, 2016 I was hoping to find a compound whose strongest line was in the near infrared: Nobody is going to be surprised to see a bloom in their camera if the light is visibly blinding. Link to comment Share on other sites More sharing options...
Fulmen Posted February 15, 2016 Share Posted February 15, 2016 Then the IR tracer formulations would be your best bet. Link to comment Share on other sites More sharing options...
lloyd Posted February 15, 2016 Share Posted February 15, 2016 I'm unaware of any pyrotechnic devices which emit strongly in the IR region and do not also produce a fairly strong visible light. We used a very few of them in the '60s, but they're more common now as aircraft decoy flares, launched in large volleys. They're ALL quite visible, in addition to providing that 'false target' IR signature necessary to deflect missiles. LLoyd Link to comment Share on other sites More sharing options...
Mumbles Posted February 15, 2016 Share Posted February 15, 2016 Your best bet for a primarily IR emitting species is probably Cesium. It at least is the best I know of. It has a few moderate strength visible bands in the purple and red region, and several very strong lines in the near IR and IR. Being the best suited from a physical standpoint is not the same as being the best suited from an economics standpoint. Link to comment Share on other sites More sharing options...
Fulmen Posted February 15, 2016 Share Posted February 15, 2016 Standard IR flares will indeed be quite bright as it's the easiest way to get IR and doesn't impede it's function. I have a few 556 IR tracers somewhere, just never got around to testing them. Most ranges frown upon shooting after the dark, and they're mostly a curiosity although I do have a Russian NV-scope to go with them.I doubt the IR tracer compositions will be invisible, but they are usually designed for low visibility outside the IR range. Link to comment Share on other sites More sharing options...
dbooksta Posted February 16, 2016 Author Share Posted February 16, 2016 Yeah, I'm coming to the conclusion that LEDs may be the way to go for this. I did find that Potassium has an absolute peak about 766nm, so as far as elements go it would probably be the best for a near-IR flare. Link to comment Share on other sites More sharing options...
Recommended Posts