To do this project, all you'll need is a 3.5mm Floppy Disk and a cheap digital camera. A digital camera in a super cheap phone could easily be suitable, we'll get to why cheap is important in a second, but for right now I'm going to address that double take you're doing. A Floppy Diskette? Yes, a floppy Diskette. While not much use as a storage medium anymore, it does have the useful property of blocking most visible light while allowing most infrared light to pass through. But most companies have discontinued manufacturing of floppy diskettes, and they can be a little hard to come by. Any of the following links might die when supplies run out.
You will need to get ahold of the clearest packing tape you possibly can, the kind they use as a sort of ad-hoc way to laminate shipping labels. The clearer and thinner the better. This Shurtape PP-803 is some of the clearest and thinnest I've used, but I have no reason to think it is the best other than my anecdotal experience. This might be useful information to have on-hand.
You should also have a small pair of sharp scissors, and a pair of tweezers will help you keep from getting fingerprints on the filter you will be building.
Additionally, disclaiming the title, don't rely on me for real counter-surveillance tips. If you need that, you'd be much better off getting your information from the Electronic Frontier Foundation, The Guardian Project, The Tactical Technology Collective, or another similar organization who makes it their mission to protect people from the dangerous erosision of privacy we're experiencing. I write these articles because they're enjoyable and I hope they are informative, but I can't save your life with a blog. So, as always, grain of salt.
Why You Shouldn't Use Old Floppy Disks For This Project
The history of computing is important, and much of it is housed on fragile, obsolete media like ancient cellophane tapes and thin magnetic film slices. This data can be precious in unexpected ways, sometimes even valuable. If you must recycle an old floppy disk for this project, you should back up the information on it first as a disk image, then upload it to a server of your choice for safekeeping. Do not commit copyright infringement, don't share anything you're not allowed to by your terms of ownership, but don't let the information go to waste.
If you need a floppy drive to do your backups with, external drives are really cheap these days.
Out of the Pulpit, on to the Practical
So you wanna know something else neat about floppy disks? They block out almost all visible light, but they let almost all Infrared light through. They aren't perfect infrared filters, but they work great for detecting certain types of Infrared Security Cameras. How? Well it's actually pretty simple.
First, find a suitable phone and set it up.
The first thing you're going to need is a digital camera of some kind, with a low-end Infrared Filter which doesn't attempt to filter out any more than the average, ambient ultraviolet light given off by say, the sun. This means that cheaper, older cameras can be recycled and put to this use fairly easily, as well as cameras in cheap smartphones and even feature phones if they support increased exposure. In order to test your camera's IR filter, get a remote control with fresh batteries and go into a dark room. Press buttons on the remote while taking a picture with the camera. If you see a bright purple flash in the picture, congratulations! You have a phone with a suitable Infrared filter.
Now that you have your camera, turn the "Exposure" setting up as high as it will go. If you can change the default settings, you may just want to make maximum exposure the default setting. Now set it aside for later.
Second, get the required piece of the Floppy Diskette
Next, get one of your floppy diskettes and hold it flat by either side. Gently bend it until you hear the sound of the glue cracking in each of the corners of the diskette. Pull off the metal protective plate from the diskette and carefully remove the film material within. Carefully cut a slice of the material which is just large enough to cover the lens of the camera from a section which your fingers have not touched. Pick the slice up with your tweezers and place it on a clean sheet of paper and set it to the side.
Third, apply the Floppy Diskette to the Camera Lens
Put your camera flat on the table with the lense facing up. Pick up the slice of floppy diskette material and place it on the lense. Pull some tape off the roll, then use your scissors to cut a clean section, devoid of oil and dust as much as possible. Quickly use the tape to secure the floppy diskette material to the lens of the camera. Press it down firmly and then wipe the surface with a clean towlette.
And there you have it. Now the camera will, as near as makes no matter, only detect light from the Infrared spectrum. On to why that's important:
Why it works
Because security cameras that need to operate at night have to find a way to illuminate the field without introducing light pollution or informing uncareful persons of their presence. In order to do this, they use these big arrays of infrared LED's which illuminate an area with Infrared light, which they then use to produce the security image. We use this to our advantage by using it to detect the presence of the Infrared emitter by making it the most visible light source in our field of vision. Hold your camera up and look for purple-to-white areas of light. Those are Infrared emitters, usually indicative of IR photography nearby.
For more information on Infrared Hacking, visit my project blog for ig88ROM at ig88rom.github.io.
First, you need an On-The-Go USB cable. This is a USB cable that has a male Micro-USB end and a female standard USB end. This allows you to attach a peripheral USB device to your phone like, in this case, a USB Wireless Adapter. 