There is a lot of talk about realism without defining what is realistic and what is not, and the definition is meaningfull and affects real world behaviour

I used to work for my local town council as the community artist. Mainly I would go round the town and paint what I thought people in the future might like to see of the town. About 30% of the time though my boss gave me a photograph to interpret, To make the photograph 'realistic' I put it through a procedure that would correct the perspective -incease the size of the centre of the image and correct the lines to the horizon at the edge of the photo. relate it to the wireframe of a poser ball.

the depth of shadows always needed to be corrected

I think really that there is no such thing as realism, only how we see something as viewd through diffent mechanisms..

looks st the 4 images provided by basicwiz, not one of them is realistic. Not one has the varirety in the normal skin tone so what value can GC be? and what normal man has that physic? Please don't take that personal basicwiz, the phenomena is pandemic.

Some of us are shorsighted /longsighted or have other vision problems.
The eye turns the image upside down and the brain inverts it again.

If we like a picture it does not need VSS, GC, IDL (looks at odnejay's work in sepia)

I think there is far too much focus the technicalities of realism to little proven end. I render very little because rendering removes the vitality of pictures. It softens and blurs and produce so little worth looking at