Hi all, after some experimenting I have to correct my previous statement that a modified webcam (after removal/exchange of the IR filter) is unsuitable for thermal imaging. Here are my learnings: - Objects hotter than approx. 260 degrees centigrade (about 500 degrees Fahrenheit) seem to “light up” in the near infrared image. The hotter the brighter, so at least a relative temperature comparison is possible, to some extent. The tip of a hot soldering iron, for example, appears to shine quite brightly when looking at it through a modified webcam. - Hot combustion gases show up brightly in the IR image, even if they are invisible to the naked eye. (Not sure if it’s the CO2 or some other gas that causes the effect. As a proof, here are some videos taken simultaneously with three cheap webcams of the same brad and model. One had the IR blocking filter removed, anouther one had the blocking filter replaced by a filter blocking visible light (i.e. only letting IR pass to the sensor), and the third camera was not modified at all. The so-so quality of the videos is not due to the camera but due to the slow computer used for recording and encoding. If the videos don’t play in your browser, downloading them may help. This is me frying an egg as seen by a normal webcam (visible light only): https://onedrive.live.com/redir?resid=6838BE39B86A56AC!178&authkey=!AKrXza_7QKYre8s&ithint=video%2c.mp4 Please note the familiar short, blue gas flame. Looking only at the IR componente with a modified webcam, the flame looks totally different: https://onedrive.live.com/redir?resid=6838BE39B86A56AC!176&authkey=!AOAS5uk5p0QffiA&ithint=video%2c.mp4 The hot gas moving upward is visible, and after shutting down the flame you can see the metal frame “glowing” for quite a while. The frying pan itself does not light up because it never really exceeds 200 degrees C. Here is a post-processed version of the video with a so-called gradient-mapping applied to the IR video: https://onedrive.live.com/redir?resid=6838BE39B86A56AC!177&authkey=!AKwVxXkHqhw0Z_k&ithint=video%2c.mp4 The camera that only had the IR blocking filter removed but no blocking filter for visible light installed took the following video: https://onedrive.live.com/redir?resid=6838BE39B86A56AC!179&authkey=!AOZAg8XGkhGL0aQ&ithint=video%2c.mp4 (The videos were recorded simultaneously, and the lights in my kitchen are fluorescent ones, containg very little IR. Things look quite a bit different under incandescent lights.) So after initial doubts I do see some value in using modified webcams for IR imaging of rocket motor tests. Compared to low-end FLIR cameras the resolution is higher and the cost is nearly negligible (less than 15$ for the cameras I used). You can observe the flow of exhaust gases and see where things get really hot (>260 degrees), and I could imagine that IR penetrates the smoke a little bit better than visible light. Absolute temperature measurements, however, would probably be impossible or at least require quite a bit of calibration work. Only a single egg was hurt in the process of recording the four videos ;-) (The other 11 eggs from the same box will be hurt later.) Hope it’s interesting. I’ll send the cameras to Vicente, who started this thread. Have a good day! Mattias From: sugarshot-bounce@xxxxxxxxxxxxx [mailto:sugarshot-bounce@xxxxxxxxxxxxx] On Behalf Of Lampe, Mattias SLC CT PEK Sent: Sunday, May 04, 2014 10:12 AM To: sugarshot@xxxxxxxxxxxxx Subject: [SS2S-Main] Re: Infrared webcam Hi, I think removing the internal IR filter works with most webcams, and if you want to make sure you ONLY see the infrared but not the visible part of the spectrum, you can add a filter that only lets infrared light pass. A piece of overexposed and developed color negative film (like from the beginning of a film roll) works quite well for that purpose. It blocks nearly all visible light and is quite transparent for IR. If you know someone who still shoots pictures on film or someone who did so in the past and kept the negatives, they should be able to find a suitable piece of material. Not sure how you want to use the IR camera, but you should be aware that it will not be a thermal imaging device. It will be sensitive only to near infrared, and in order to emit those wavelengths a body must be quite hot already, i.e. close to glowing. I have a few unused webcams at home and will check if they can be converted. Have a great day! Mattias From: sugarshot-bounce@xxxxxxxxxxxxx<mailto:sugarshot-bounce@xxxxxxxxxxxxx> [mailto:sugarshot-bounce@xxxxxxxxxxxxx] On Behalf Of James Fackert Sent: Saturday, May 03, 2014 1:18 AM To: sUGAR sHOT TO SPACE LIST Subject: [SS2S-Main] Re: Infrared webcam here is one, $30. http://www.adafruit.com/products/1567 On Fri, May 2, 2014 at 9:53 AM, Lyn Berry <lyn_berry@xxxxxxxxxxx<mailto:lyn_berry@xxxxxxxxxxx>> wrote: Hi I am no expert but if memory serves webcams contain an IR filter. If the filter is simply removed the webcam becomes much more sensative to the IR part of the spectrum. QED Regards, Lyn Berry On Friday, 2 May 2014, 12:52, Vicente Alvero Zambrano <vicente_alvero_14@xxxxxxxxxxx<mailto:vicente_alvero_14@xxxxxxxxxxx>> wrote: Hi, Does anyone know and is willing to turn a webcam into a webcam with infrared vision for the series of motors VIC and to study the ablative materials? Cheers Vicente Alvero