|Simone models her scary giraffe costume in visible and near IR|
There are many things that can be explored with a near IR camera. One of the more surprising things to observe is paper money. The back of $10, $20, and $100 bills have strips of near IR reflecting pigment that obscure the printing behind it.
|The reverse side of a $20 bill in visible and near IR|
|The reverse side of a $10 and $100 bill in near IR, notice almost invisible 100 on right|
The counterfeiting measures on the front of the $100 bill look very different in near IR. The inkwell disappears revealing the Liberty Bell. This happens in visible if you tilt the bill. The fountain pen and phrases from the Declaration of Independence disappear and the security ribbon becomes very faint.
|Obverse of $100 bill in visible and near IR|
Near IR passes through black plastic bags. You can shine an IR LED through it or place IR emitters like this space heater behind it and see right through the bag.
|Visible and near IR image of a black plastic bag draped in from of space heater|
|My classroom with all the fluorescent lights on in visible and near IR on a foggy morning|
|The red LEDs of my binary clock and shining a remote control on my face in the dark with a remote control shining on it|
|South San Fransisco Bay Area from Saratoga, distant mountains only seen in near IR include Mission Peak|
|Colonial Peak looms over Diablo Lake in North Cascades National Park|
|Los Gatos High School pool in visible and near IR|
I hope I have piqued your interest in near IR imaging. Near IR cameras can be made by modifying a webcam. All you need to do is replace the IR cut filter with an IR pass filter. Another option is to purchase a Sony Nightshot camera and place a near IR pass filter over the lens. You can find used Nightshot cameras on eBay for less than $40. I will describe both of these options in detail in my next post. If you can't wait, there is a lot already posted on the Internet, search "DIY infrared webcam".