When does height difference start to get noticeable

[Deleted member 2119]

In a lot of shows when the actors have an inch height difference they basically seem the same height. What height is it clear someone is taller than the other to everyone and not just heightspergs?

 

[Deleted member 6382]

2-3 inches

 

[Deleted member 4106]

3 inch

 

[Deleted member 4720]

Frame plays a big role in this imo