IR photography is fun. However, getting a proper IR filter (technically a visible light filter but whatever) for your camera can be a pain, especially if you only have a point and shoot, or in my case, a cell phone. Sticking true to my "Poor Man's" philosophy of using only things I have around the house to make this, all that is required are 4 things:
*A cell phone (obviously with a camera on it)
*A case that fits snugly on said cell phone
*A floppy disk
*A pair of scissors
IR photography requires an immense amount of sunlight (or IR lights) to properly expose shots. That being said, do not look into the sun, with or without the filter on your phone.
*This isn't technically a true IR filter. However, for the price it does the job well enough.
Step 1: Camera Check
The first and most important step of this is to check that your camera does not have a good IR Blocking filter in it. Most cameras do, but they are cheap and only meant to filter out IR from visible light pictures. Some cameras have very good ones, which block nearly all IR light, and this filter won't do anything if yours is one of those.
So how do you know if your camera has a blocking filter? Turn the camera on, get a remote control of some kind (TV/DVR/etc etc...), point the end of the remote with the IR LEDs in it (the end you point towards whatever you are trying to control/the end that has little LED bulbs on it) towards the camera lens, and press buttons. You should see them light up (probably purple). If you don't see anything, make sure the remote isn't dead and that you are pressing a button. If you still don't see anything, then you have a good camera and unfortunately the only way to continue is to take it apart. If you do see them light up, congrats! You have a camera capable of taking IR pictures.
Step 2: Break Your Floppy
Take your floppy disk and flex it between your hands until you hear a crack. This will release the adhesive holding the two halves together, allowing you to obtain the actual disk from inside. This is what we are after.
Step 3: Assemble Your Filter
Using your scissors, cut a small piece from the floppy that is large enough to completely cover the opening for your phone's camera on the case. Position it in the bottom of the case over the opening, and insert your phone. You are now done.
Step 4: Photographing in IR
You will notice that when you attempt to use the camera now, you more than likely can't see anything. That is because the film from the floppy disk blocks most visible light coming through it. If you hold it up and look through it, chances are you won't see anything. What it does allow through is IR light. The sun gives off most of the IR you will use to take pictures, but other things such as IR LEDs, lightbulbs, fires, and heating elements from stoves give off IR light as well. This being said, in order to get a proper exposure you will likely need to be outside on a sunny day, and if possible, set your exposure to +1 or +2.
Some of the best things to shoot in IR are plants. They reflect IR very well. The color of the film will come through in your IR pictures, so shooting in black and white makes for great pictures in IR.
Above are some examples of things photographed with this IR filter on my HTC Rezound. The first is a 60w equivalent daylight CFL, and the second is outside on a cloudless day at about 2pm. You can see how much light you lose putting the filter on, so remember to shoot with as much light as you can. I didn't bother doing any post-processing with these pics, but a little touch up can definitely help.