Camera.aspect is incorrect (4.5.4 f1)

Camera.aspect should remained the same if I pick something other than “Free Aspect” and scale the play mode window around.

This is not the case. I Debug.Log(Camera.mainCamera.aspect) and it is shown that the value returned fluctuate around while I was resizing play mode window. Why is this happening?

It will only change if you have the camera set to free aspect before running, and change it to something else later while running. If you set the camera to a specific ratio before running, then it won’t change.