Old Photo Blogging

While Glenn has been busy photoblogging with modern digital cameras, TangoMan at Gene Expression is blogging about the century-old color photographs of Sergei Mikhailovich Prokudi-Gorskii, "Photographer to the Tsar."

I didn't even know that there was a color-photography process as early as the 1900's and 1910's. But there was, and TangoMan links to the page explaining how three different grayscale images were taken with blue, green, and red filters and then projected onto a screen using the same three filters. (Commenter Jesse also points to these links on "autochrome" technology).

Laws of physics being what they are, it shouldn't be surprising that similar filtering and combining techniques are being used to beam us color pictures from the surface of Mars one century later.