Spectral Colors (The visible spectrum)
Infrared (Wavelengths of about 1 mm to 750 nm)
Electromagnetic Spectrum (Unfiltered)
It is not absolutely necessary to remove the "eye" PCB. Doing so makes it easier to work with.
Before the lens can be unscrewed, the hardened glue needs to be scraped away. An exacto knife works well for this task.
Once unscrewed, the infrared blocking filter element can be removed. This will likely take some work. Part of the plastic housing may need to be removed in order to extract the filter.
Removing the lens shielding is accomplished by pulling back the plastic tabs found on the main case, then working the shielding tabs out through the 4 openings on the main case. Do not attempt to bend the green tabs of the shielding. They are very brittle. Once the shielding has been removed, cut or file the inner portion of the white case tabs to remove the locking wedges. This will prevent the shielding tabs from snapping/locking to the main case. With the locking tabs removed, the shielding component will become detachable, yet fit snugly in place when attached.
After removing the lens shielding, the plastic disk is exposed and can be removed by simply applying pressure. The glue which holds the disk in place is not very strong. Use a blunt object that will not scratch the plastic disk, such as a pen cap.
The IR filter element is adhered to the plastic disk. If something is to go terribly wrong with this project, this is likely when it will happen. Because of it's small size, the IR filter is difficult to work with. And, adhering it to the disk requires a great deal of precision. In addition, conventional glues can not be used for the fluid will seep under the filter and distort light as it passes through. Hot glue works well because of it's gel like properties. This also allows for an "undo", in case the filter is not positioned correctly on the first attempt.
The disk is then fastened to the lens shielding. The filter element is positioned on the camera side of the disk, allowing the disk to protect the filter.
Use this lens for NORMAL mode.
I repeated the last step substituting the IR filter with black film negatives. Infrared light passes through film negatives regardless of how dark the film may appear to the unaided eye. At the same time, dark portions of film negatives block light rays which create spectral colors. Therefore, film negatives can be used as an exclusive IR pass filter. Click here for a video demonstration of this phenomenon.
Use this lens for IR mode.
I used this opportunity to paint the "eye" portion of the main case. The results are mostly cosmetic. However, it does help keep light from bouncing around near the lens. A flat paint is preferred over what I had handy.
FULL mode is accomplished by using your camera without either lens attached.
Unlike visible light, IR light does not cause ones iris to change. In a dark environment, the eye can become exposed to large amounts of IR light without any pupil constriction, which leaves the retina exposed. It is unknown weather or not IR light is harmful to the human eye.
The light from night vision cameras is visible in FULL and IR mode.
This demonstrates how colors appear while recording in different modes.
Since monitors and televisions do not produce infrared light, they appear to be turned off while viewing infrared light exclusively.
Some dyes/inks allow infrared light to pass through them.
The only light in this video is IR. To the human eye, this appeared to be completely dark. This technique is the essence of "night vision".
This demonstrates how a twenty dollar bill appears under different modes. Notice, a vertical band of ink is invisible in IR mode.
As mentioned above, film negatives allow IR light to pass through, making the film transparent.
The read-side of popular "Black" CD-R's, do not block IR light. This allows IR rays to pass through the filtered plastic and reflect off of the actual metal, making them appear as normal compact disks.
The normally invisible IR light emitted by IR communication devices, such as those found on television remote controls and computer (usually laptops) IR ports is visible to the camera while the IR blocking filter is removed.
Recording video in the absence of a camera's IR blocking filter usually results in bright, colorless images. However, the image on this LCD monitor appears to be sharper with improved saturation when viewed without the IR blocking filter. Since monitors/televisions do not produce IR light, the camera's image sensor is not overexposed while receiving all possible light. Therefore the image does not appear to be washed out and is actually enhanced.
Full mode is especially good for poorly lit environments. This allows the camera to be used in situations where the resulting footage would normally be too dark. This, of course, comes with the sacrifice of color saturation.
Other mods I have performed on my CVS camcorder