20/20 is actually pretty bad eyesight. It's "normal vision", not perfect vision, and when my eyes are "corrected" to 20/20, they're about a quarter-diopter shy

20/20 is actually pretty bad eyesight. It's "normal vision", not perfect vision, and when my eyes are "corrected" to 20/20, they're about a quarter-diopter shy of maximal acuity. There is a huge difference to my eyes between pictures printed at a 200-line screen and one printed at a 150-line screen (all other things, like stock and varnish being equal) at a distance of more than one metre (from head-height on a couch to the magazine at the far end of a coffee table). If I were printing from a 12MP original at about four feet tall, I'd certainly run the source through something like Genuine Fractals Print Pro (even a good giclee pattern can't make up for squared-off curves). At four feet in the long dimension (giving a realistic viewing distance of about six feet) I'd notice raggedness at a glance at less than about 80ppi -- but then the dye clouds from a 4x5 negative printed at that size would drive me batty as well.