In Does the universe actually look like that? , Planetary Astronomer Mike finally satisfies everyone who looks at those beautiful photographs of galaxies in newspapers and wonders “Hmm, how much did they doctor that photograph to make it look pretty?”
The answer turns out to be more complex than just “a little” or “a lot”. P.A.M. explains how those pictures are actually made, and how the equipment’s characteristics basically force astronomers to do post-processing on the images, even just to be scientifically accurate (let alone beautiful). It’s a great post, very detailed but extremely readable.