Had one, never used it. Rep is quite good lens, weak shutter. As with any focal-plane shutter camera, if you hold the body with lens and back removed against a light (like a window) and fire the shutter at all speeds, you should see a complete rectangle with sharp corners if the shutter is opening OK. This doesn't of course test the accuracy of the speeds, although you can guess whether they sound right, but at least you can establish that the shutter isn't "tapering" (not opening until partway through its travel).

Regards,

David