I have an old M42 lens which I mount using an adapter on to a Sony e-mount mirrorless camera. I have vandalised butchered modified it to get a particular effect. This has worked to a point, but has also turned it in to a macro lens incapable of infinity focus. I should be able to get this back by bringing the lens closer to the camera, but I can't figure out how to do this. The adapter is approx 1 inch long, similar to this one so I have plenty of room to mess around before the lens causes a problem with the shutter. Short of commissioning a custom adapter to be made, or learning metalwork myself, I can't think how to make this work. Ideas?