Value list sort

Hello friends

I have a database that has a field <<Photographers>>. I also have a table where I enter the Photographer's info such as NAME, PHONE AND LOCATION

The <<Photographer>> field is a drop down menu based on Photographer's table <<Name>>, I would like to show the list based on their location. how do I do that?

here is a sample

Dave Saint John

Mac Toronto

Rick London

Steve Paris

Shelly Paris

Ben