What are normal MAGFIELD and COMPASS OFFSET numbers?

What are the acceptable MAGFIELD and COMPASS OFFSET limits for Pixhawk and Ublox LEA6 w/ magnetometer? And what is optimum?

It looks like the magfield can be anywhere from 874 ~ 185 before the compass pre-arm checks will fail.
github.com/diydrones/ardupilot/ … fig.h#L350

 The mag field strength depends upon where you live.  Here in Japan it's about 475 and I think that's typical for many places in the world.

 The compass offsets should ideally be zero but they never are.  With the APM2 we use to say that all should be between -150 ~ 150.  That's still generally true but we see higher numbers than that some times.  i'd say if you see less than -250 or more than +250 then they're a bit high and there might be some metal near the compass which isn't good.