I recently got a Tamron 90mm macro lens (non vc) but when I use live view with it and decrease the shutter speed I notice a strange noise that sounds like it's coming from the camera. It doesn't happen without live view enabled and it doesn't happen with any of my other lenses.
Also, in low light situations with this same lens and with live view, I notice bands on the screen. Again, this doesn't happen with other lenses and it doesn't seem to show up in my pictures.
Any ideas on what might be causing this? My camera is a rebel t5.