As you've already mentioned, cells near the primate macula tend
to make one to one connections. Due to this lack of convergence
they can be somewhat smaller than normal cells (particularly in
the size of their dendritic arbors) earning them the moniker
"midget" ganglion and bipolar cells (also P cells). By reducing
the magnitude of photoreceptor convergence onto ganglion cells,
the retina sacrifices luminal sensitivity for spatial acuity. Or
put another way, a downstream neuron in the LGN/V1 can be more
"certain" about which photoreceptor is sending information when
light is bright, but less certain that any information is being
sent when light is dim. The other side of the question you bring
up is how the retinal ganglion cells themselves alter the image
formed onto the photoreceptor layer. For those that don't
already know, photoreceptors are located at the very back of the
retina. Since they're the major light sensitive part of the
retina, that means light has to go through the ganglion cells,
bipolar cell