Research Notes

White balance

cfastie — Mon, 17 Jun 2013 03:31:33 +0000

Image above: Some of the surfaces I used to custom white balance the infrablue SX120

Histograms

cfastie — Thu, 13 Jun 2013 22:18:25 +0000

There have been a lot of questions recently about how the color information in infrared images translates into NDVI values. So I finally started to pay attention to image histograms. These are part of the secret language of photographers. They are really just simple graphs, but photographers and photography programs always seem to display them with no labels on either axis, so they tend to be impenetrable to the uninitiated. Staring at image histograms has been helpful to me, and maybe it will help you too.

Rock Tripe Slab

cfastie — Tue, 11 Jun 2013 00:48:07 +0000

Image above: Rock tripe (Umbilicaria sp.) and other foliose and crustose lichens cover a tenth of a hectare of the steep face of Rock Tripe Slab (previously known as "That big ledge up there"). Three cameras contributed to these images. Two cameras were required for both images along the dextral diagonal, one camera each for the images on the sinistral diagonal.

Infradark

cfastie — Thu, 06 Jun 2013 23:02:28 +0000

Image above: Will Ward's nighttime infrablue and normal photos.

Invisible Rays

cfastie — Thu, 09 May 2013 05:41:30 +0000

Image above: My backyard in pure infrared light. A Wratten 87 filter allows only wavelengths longer than 730 nm to reach the sensor of the Canon A495.