handheld Infragrams of 462 Halsey Garden, Brooklyn

My attempt and results

I shot Infragrams of this mid-lot community garden, hoping to see differences in where plants were well-established and where they were just getting started. I was also interested in

Questions and next steps

I'm wondering about the white balance card -- when is it important to use it? I feel the range in the example below is lacking calibration -- there are clearly areas of intense photosynthesis and areas where there are none, but the NDVI values are all middle of the road.

Another example of lacking calibration:

Wonderful photo of Rose