Backround image scaling I have a couple of reference images that I'm trying to set up correctly

There are two views:
front 263x490 
side  766x490

I am using the background images function, however it seems that they are being scaled differently.
It looks to me like the side view is scaled based off the width of the front view.
Is there a way to change this?
,
.
My solution was to increase the canvas size of the front view image such that its dimensions matched those of the side view.
i.e. 263x490 becomes 766x490, to match the right side view resolution.

It seems to be that blender attributes the largest side of the first background image 10 blender units and goes from there, throwing things out of whack if your images are cropped.