Hey everyone - my first thread post opening! Great to be on this awesome forum!

I'm back into large format shooting lately and with my Sony and MFD setup I figured I can start copying my 5x4 and 10x8
negatives. I'd most likely build my own back-lit diffused box with strobe to light, and vertically mount the camera/lens rig
as any typical copy stand we're all familiar with.

My query is what's suitable lens for this degree of copying/capturing resolve of say a 100 ISO 10x8 negative? Which Rodenstock or SK will have enough pulling power for copy on say my A7R (stitched together)? I'm thinking the 60mm or 80mm ought to be a solid starting point.

Any ideas?