The prints were actually crops corresponding to A2.
I consulted two of my friends, one is much younger and may be better eyseight, the other one is a guy who was working at one of the best professional labs in Sweden. This lab was employed by the famous photographer Lennart Nilsson, famous for pictures about life, http://en.wikipedia.org/wiki/Lennart_Nilsson
What the lab guy said was that the A-700 print had slightly higher contrast and therefore may look sharper, but he failed to see any difference.
The both images were done using the following pipeline:
- Raw conversion lin Lightroom with same sharpening presets (landscape?)
- cropping to 50% in linear scale (so we see 1/4-th of the area)
- printing on A4 paper with interpolation to 480 PPI, and standard output sharpening for glossy paper
So the prints were actually A4 but the crops corresponded to A2.
I was very surprized when I saw the result.
I have also scanned the prints at 600 PPI, but the files were to big to use.
I'm not really in the lense/camera/printer testing business, but want to share my experience. The idea that some readers may some money on my input.
I would agree with this. 16x24" (roughly A2) has always been my cutoff for most 12mp images. This requires using good glass, shooting technique, and post-processing as well as avoiding cropping. I find that 24mp does make a noticeable difference over 12mp in 16x24" prints on close examination; but the real benefit to 24mp is being able to make 20x30" prints with slightly better quality than my previous 16x24" prints. 20x30" at 200ppi looks great even from fairly close viewing distances.
Really? To me the difference is apparent even in the scans of the prints from your example. Of course that's not quite the same as comparing actual prints. Maybe the scans are equivelent to sticking your nose in the print. But my experience is that you don't need a loupe to see the difference between 12mp and 24mp at that print size.