What I want to do
Motivated by Chris Fastie and Ned Horning's work, change internal filter on A1200 from exposed color film (for NIR two-camera approach) to Wratten 25. I already tried the Wratten 25 as an external filter on an A490. However, I wanted to mount the gel film inside to protect it. Try it for NDVI.
(Updated: 1. Took 85 more test images, revealing internal blemish in some specific lighting conditions. Not sure if it is a fingerprint on filter or sensor, or something else. Most images appear ok 2. In response to comment tried processing without stretching vis or NIR using Ned Hornings Fiji tool)
My attempt and results
Updated as noted above: Composite showing example images with blemish:
Contact sheet views of as shot images, mostly ok and portion of processed images:
Composite image showing result of processing without stretching vis or NIR using Ned Hornings Fiji tool
End of update
Photos of conversion: [For initial conversion for NIR two-camera approach, see prior note].
For Wratten 25 filter material, see prior note.
First testing image examples of my front yard in Livermore CA were shot after custom white balance in sun using red file folder:
Images processed with Ned Horning Fiji tool with blue channel for NIR and red channel for red; with the Chris Fasti lut. Thanks again to Chris for his helpful comments on the A490 initial test results.
Questions and next steps
Tune white balance or other parameters to improve results.
Why I'm interested
Continue to explore as tool to assess vegetative health.