Thanks so much Dan! With a bit of tweaking, this is working quite nicely. Here’s what I ended up using:
d = thisComp.layer(“Camera 1”).transform.position[2];
minScale = [1.5, 1.5];
maxScale = [100, 100];
dAtMinScale = -7000;
dAtMaxScale = 10;
linear(d,dAtMaxScale, dAtMinScale, maxScale, minScale)