I find this image interesting on a few accounts.

This is a 100% detail of the preceding image which is a 4000 pixel high crop of a 6000 high original.
It is taken with a Sony a850 at ISO 640 and boosted 0.4 EV in RAW ‘development’ as well as the shadows opened up slightly, primarily to define the eyes.

While on close inspection, noise is starting to intrude, it wouldn’t show in any normal sized print.
The ensuing loss of detail still leaves the delicate hair on the arm and weave of the cloth well delineated.
Properly prepared, I wouldn’t hesitate to print this at 16x20 inches.

This image was taken with a 25 year old Minolta 28-135 zoom lens, a flawed but amazing optic.

The 24MP camera is the limiting aspect.