Does scale of camera have an effect on camera tracking a scene? I am doing a camera match/track (markers on the floor and walls, they are scaled differently and key frames on necessary frames when something passes in front of the tracked point).  Sorry if this doesn't make sense.

I click the "solve camera motion" and then "set up tracking scene", and then I noticed the focal length of the camera is set to 4 mm, which looks extremely wide angled.  So I manually put the focal length to 35 mm, which looks right; then I look at the scale of the camera and the "empties" in the scene and it's scaled to like 0.1 instead of 1.0.  


Anyone know what is causing the scale to adjust like that?
And can it still be used, or should the scale be 1?


Not sure how to edit this:  It appears the "Camera Solver" constraint is what is setting the camera scale, can anyone shed light on that, in layman's terms?

Any input is greatly appreciated.
The scale of the camera is irrelevant. The scale of the scene is not.
The scale for the 3d reconstruction of the scene based on tracking information is arbitrary.
If you happen to know what the distance is in the real world between two  of the elements being tracked, you can use that to inform blender to scale the tracked scene based on that distance. Select the trackers and set and apply the scale.

Read: Camera tracking reference scene to match different shots in a common space
But even if you don't set the scale when you solve the scene, you can scale and reposition all empties and camera with ease. If you move any of the elements of the tracking constraint, all of the elements will move as they all depend on the camera. It is here that you can scale the camera to make the reconstruction be the scale you want.

For a comprehensive post on motion tracking read:
How can I get better results when doing camera motion tracking?