Whether I shoot pictures of the Orion Nebula through a telescope or scenic views with a tripod-mounted camera, Ektachrome P1600 has high effective speed and gives quality images with pleasing color balance. Its grain structure is comparable to ISO 400 emulsions. The history of color films popular with amateur astrophotographers is well documented in the pages of this magazine. Flipping through past issues reveals that slide films dominated during the 1970s and early 1980s. Both types have their strengths and weaknesses, but the large selection of negative films with high speed and broad spectral response has given them an edge in recent years.
Negative films are also popular with photographers who do their own darkroom work.
Custom lab work is expensive, and the people who operate the automated printing machines in 1-hour photo stores usually don't have a clue as to what color the Orion Nebula should be. An attractive alternative is slide films. These do an end-run around the problems of color printing, offering a finished image with vibrant color right out of the developing tank. Color prints can always be made from slides, and the slide serves as a perfect reference for the darkroom technician to gauge the print's density and color balance. Traditionally, slide films have not offered the high speeds available with negative emulsions.