Images of Middle Cambrian chancelloriids. A. Allonnia, Burgess
Shale, British Columbia (ROM 49601A). Immersed in water. A1.
Plain light. A2. Red channel of image taken with
crossed nicols subtracted from green channel of image in unpolarized light,
using Adobe Photoshop’s “Subtract” blending mode (settings: Opacity = 100,
Offset = 75, Scale = 1). Levels subsequently adjusted. B. Chancelloria,
Wheeler Shale, Utah (USNM 509795). B1.
Crossed nicols. B2. Red channel subtracted from green
channel, using Adobe Photoshop’s “Difference” blending mode and adjustment
Click on image to toggle between A1,
B1 and A2, B2.