Why is this simple CFrame code doing this?

http://gyazo.com/e6e151c996e0fe54dff0603fe0a07f36

You will see that when I zoom in completely and move around, my arms sway. They aren't supposed to. They're supposed to stay fixed like they are when you see me zooming out and turning.

Does anybody know why my arms are swaying while in first person?

This is the piece of code that deals with the head's lookVector (arms are bound to the head):

game:GetService("RunService").RenderStepped:connect(function()
    char.Torso.Neck.C0 = (((CFrame.new(0,1.5,0)*(camera.CoordinateFrame-camera.CoordinateFrame.p)):inverse()*(char.Torso.CFrame-char.Torso.CFrame.p)):inverse())
end)