It's a function of how those emission regions land in the photographic sensitivity regions. Amateur astonomers see similar drastic problems. Here again the narrow band sensitivity of photographic emulsions is being tricked. Photo-emulsions cannot reproduce nebulae faithfully, because nebulae emit in only very narrow emission lines, which will either hit or miss the narrow sensitivity regions of the emulsions. It turns out that the red Hydrogen-alpha line is a direct hit for the red band of most photographic emulsions, while the green oxygen lines our eye sees are something of a miss.
Color is obviously vital to our everyday life, for asthetic pleasure but also for necessity.
Next month, I'll discuss how the information contained in color is perhaps as vital to astronomy. For a complete listing of article comments, questions, and other discussions related to Wesley Colley's Astronomy topic, please visit the Discussions page . All rights reserved. Used under License.