Following an interesting talk at Cambridge Camera Club yesterday, I was moved by the combination of sunshine and blue sky with a few clouds to take out my infra-red converted camera for a walk before dusk.
Infra red converted cameras are sensitive to reflected infra-red and particularly foliage glows white as chlorophyll reflects lots of IR. Blue sky reflects very little, so ir rendered dark.
I am including some of each of the commonest IR presentation techniques. Straight out of the camera for a surreal colouration (those with the red sky); channel swapped where I have rendered all of the red stuff in the original as blue and vice versa which returns a blue sky, but still fairly surreal; finally I have rendered most of the images in monochrome which gives dark skies and glowing vegetation.