Pinkfoot or Greylag?

We had some geese stop in for a visit, this morning.

These two stayed away from the rest, for some reason, and wandered away from the pond to the beech avenue and turf nursery.

It's surprising how few animals are afraid of cars, and I just drove up and started firing away through the passenger side window!

...but are they greylag geese or pinkfoot geese, and how do you really tell?

Bigger geese