The J-9 takes a 49mm filter.
Are the threads damaged? I've had that happen. My way of dealing with it on the 5cm F1.5 CZJ Sonnar is to use a 40.5 to 43 step-up. I forced the Step-up into it with the optics module out of the focus mount, and twisted it in with a rubber mousepad.
Are the threads damaged? I've had that happen. My way of dealing with it on the 5cm F1.5 CZJ Sonnar is to use a 40.5 to 43 step-up. I forced the Step-up into it with the optics module out of the focus mount, and twisted it in with a rubber mousepad.