Just a quick hack. I came across this again while experimenting with a red-vegetation formula.
This is mainly for photographers who enjoy specific false-color infrared looks that rely on letting only a limited amount of infrared light through. A common issue is that hot mirror filters (which reduce IR, especially GRB3) often cut out too much infrared light.
So how can you compensate for that?
By reducing the amount of visible light as well. This can be done with an ND (neutral density) filter or, alternatively, with a polarizer. These filters generally don’t affect the incoming IR light, only the visible light.
The advantage of the polarizer is that it provides an additional benefit: it can dramatically enhance the appearance and color of the sky and, of course, reduce reflections on many surfaces.
This is sort of like fine-tuning the IR as the last step.
Here’s an example:
First image: without a polarizer
Second image: with a polarizer
