Viewing a 6MP image on the computer screen at 72 dpi at 100%, one is viewing the equivalent of a 42"x28" print from reading distance. A print that size would normally be viewed from several feet away. When all that information is scrunched down and printed to an 8x10 at 300 dpi, the perception is vastly different. Things that seemed prominent - almost isolated - on the screen are integrated into the print, no longer catching our attention.
The human eye is just not a high-resolution device. At 300 dpi at reading distance, all the pixels nicely blend together into the continuous tone we know and love. As the print grows large, we can drop the resolution of the print, since we will be viewing from a greater distance, and it still looks great.
The converse is also true. I was absolutely awe-struck with the first print I made off a medium format negative, scanned with my Epson 4870. Flatbed scanners are not supposed to be capable of prints that would impress the most picky clients in the world. If I had this print made at a top pro lab, no one would complain at a $150 to $200 charge for it. Epson claims a maximum optical resolution of 4800 dpi, but since there is no standard way to measure this, it could be a much inflated claim. This print was stunning.
I found there was a forum devoted to these scanners, so I joined. Someone had just written that he had paid to have a professional wet-mounted drum scan made of a negative, that they also scanned on the Epson. He said that on the screen at 100%, the drum scan showed much more and crisper detail. He had prints made of each, and everyone who saw them together, said that the Epson-scan was the better print. The great detail of the drum scan was lost when boiled down to 300 dpi, and the gradients and nice shadow detail of the Epson scan won over the extreme resolution of the drum scan.
As photographers, we are judged by the images we present. If the print LOOKS sharp - it is. If the image on the web knocks out the viewer, it is great even at 640 x 480. No one sees our work at 100%, so that is of no relevance. Only the final image counts.
larry!
http://www.larry-bolch.com/ ICQ 76620504