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Re: [LUG] Linux-friendly web cams

 

On Thursday 22 March 2007 14:04, Robin Cornelius wrote:

> Thats quite cool, I never considered that there was a simple IR filter
> on the front.
>
> I am having some ideas for some wildlife cams. My inital thoughs are:-
>
> a Linksys NSLU2 loaded with debian of course running of a USB stick, a
> wireless adapter and a IR modified web cam (and a hub cause now i need
> 3 USB sockets). NSLU2 runs of 5v and hubs are typicaly 5v or 12v so
> battery operation is also possible so a small bit of voltage
> conversion hastle but not a big problem. Put in a water proof box, Add
> a solar pannel and a battery for day time charging and you have a
> remote system.
>

Interesting - I run my own converted cams, together with one of those cheap 
security cameras you can buy which connect to a tv card, for the exact same 
purpose. The main problem with a webcam IR conversion is light level. 
Depending on the wildlife you want to watch, some form of low level lighting 
is likely. IR leds work well, but you need a far few to get a decent output. 
To enhance the effect, I "encourage" my wildlife to visit a piece of white 
board in the garden, on which I place a small bowl with food in it. The white 
board helps to make use of the IR and you get a much better picture.
Some people use those stick in the ground night time lights which charge with 
solar power during the day - you don't need loads of light, just enough to 
help pick out what is happening. Light doesn't seem to deter the majority of 
wildlife anyway from what I have seen.
There is a guy who runs a site called beautiful britain - 
http://www.beautifulbritain.co.uk/
which has some interesting webcam stuff on it - bird box cams and nocturnal 
stuff.
I did do some experimenting with diy cheap lighting for night time. Never 
really got very far, but a bottle of coke acts as a good filter for a torch - 
it blocks most of the white light but through IR the light is fine! Likewise 
filters created from unexposed but developed film does a good job at 
filtering white light (as is used in the conversion of webcams to stop the 
white light spectrum).

Mark

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