How do you attach a 55mm filter to 50mm lens?

To attach a 55mm filter to a 50mm lens, you'll need a step-up ring that has a 50mm thread on one side and a 55mm thread on the other. Simply screw the step-up ring onto the 50mm lens, then attach the 55mm filter to the step-up ring. Ensure both connections are secure to prevent any issues during use. Always check that the filter is compatible with your lens for optimal performance.