ASP.NET MVC - Scaffolding a Drop Down List - asp.net-mvc-4

Question

I'm trying to learn how to use the ASP.NET MVC 4 and Entity FrameWork 5, and I'm a bit confused by scaffolding for Drop Down Lists.
I have three classes:
public class ScopeType
{
public int ScopeTypeId { get; set; }
[Required]
public string Type { get; set; }
}
public class ScopeManufacturer
{
public int ScopeManufacturerId { get; set; }
[Required]
[Display(Name="Manufacturer Name")]
public string Name { get; set; }
}
public class Scope
{
public int ScopeId { get; set; }
[Required]
public ScopeManufacturer ScopeManufacturer { get; set; }
[Required]
public string Name { get; set; }
[Required]
public ScopeType ScopeType { get; set; }
[Required]
public int Aperture { get; set; }
[Required]
public int FocalLength { get; set; }
}
Essentially, the first two classes are just lists of values that I want to appear in the drop downs on the 'Scope' create/edit forms. It's a 1 to 1 relationship.
I build the solution, and then add scaffolded controllers and views. Unfortunately, for the 'Scope' controller and views, the ScopeType and ScopeManufacturer navigation properties are ignored; no drop down lists are generated.
I then found on Google examples where people describe specifying the relationship between items by creating properties of integers, with the same name as the Id on the related thing. Therefore, I deleted the controllers and views, and tried again with:
public class Scope
{
public int ScopeId { get; set; }
[Required]
public int ScopeManufacturerId { get; set; }
[Required]
public string Name { get; set; }
[Required]
public int ScopeTypeId { get; set; }
[Required]
public int Aperture { get; set; }
[Required]
public int FocalLength { get; set; }
}
This still didn't scaffold drop down lists for me - rather, it gave me 2 extra fields for me to type integers into.
What am I doing wrong, or am I mistaken in believing that the scaffolding in MVC 4 will generate drop down lists for 1 to 1 relationships like that?