I noticed- just now, if I the rear element has back and forth movement- a little. So if I tilt the camera, it moves up or down the lens.

I just got a nice looking 150mm 2.8 for my 645z camera.

I noticed this lens has more internal movement than all my other lenses. It this normal? Or, is it a sign something id loose, like elements or something? If I roll the lend in my hands, I feel and hear a little movement.