forafewpixelsmore

When taking a portrait in some cases we try to keep a certain distance to have a more natural / less deforming one-eye perspective of the face. Sensor size and focal length put aside there is one thing i am still wondering. it's the fact that medium glas can be pretty big; if the frontlens diameter is close to let's say eye to eye distance so doesn't that have an impact on how the image looks? espacially when it comes to 'enveloping' the face? And doesn't big glas need big sensors to get the most out of it ? Using a panoramagimbal (nodal) and stitching should give a similar effect ...