Wratten 25A filter
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This square of Wratten 25A gelatin filter is large enough to convert four Canon PowerShot or other point and shoot cameras to plant analysis cameras. The small PowerShots typically used for aerial photography have an internal infrared block filter that is 8 mm by 9 mm. By opening the camera and replacing that filter with a rectangle cut from this filter, the camera will record near infrared light in the blue channel and mostly red light in the red channel. Those two channels can then be used to produce Normalized Difference Vegetation Index (NDVI) or false color IR images. This 2 cm x 2 cm square can also be used in front of the lens of a camera which has had its IR block filter removed. See more about what you can do with your own Super-Red Infragram camera here.
In the drop-down above add a small screwdriver with a Phillips 000 head for removing the external and internal screws of Canon PowerShots and other cameras.
|A super-red photo taken with a PowerShot modified with a Wratten 25A filter (top), a false color infrared image from that photo (NRG), and a normalized difference vegetation index image from the photo (NDVI).|