@Dilbert: I refer you to Neuro's answers for all the spherical aberration stuff. Canon DOES purposely leave in spherical aberration by design, as it is a desirable effect in many circumstances.
As for your assuming, you assume that people are trying to justify what Canon does, when in actuality people are simply explaining what Canon does. You assume that people here "worship" Canon, when in fact some people are simply fans, others are simply customers and might otherwise not care about the brand. You assume a whole hell of a lot about people here man, and then you lash out at them with thinly veiled hostility and nasty words based on your INCORRECT assumptions.
All I'm saying is...might not want to assume, you would look like less of a donkey's rear end in the end.
Totally rude and unnecessary. How can a person use such words to make a point?