What's a good way to test for decentering on the Samyang/Rokinon 14mm? [edit: - with regard to the notes in Roger Cicala's decentering articles about ultra-wide lenses giving false-positives on star charts etc]
I haven't ever really noticed a problem with mine, but hey, worth checking if it's relatively easy. I tried searching the forum for tips - but didn't come up with much specific to that lens. Maybe I need to use different search terms.