Shallowth of field of the 135 GM

I was sitting quietly when a small bird perched a few metres away. I raised my camera and caught a shot of it. Because I had my lens set to f/1.8, we get a very shallow depth of field, with only the bird in focus, and we get to see the bokeh of an extremely out-of-focus background.

I think this is a fairy wren out of breeding plumage, but I am not sure.

This image shot with the Sony 135mm GM lens on a Sony A1, at ISO 100 f/1.8 1/320. Image cropped somewhat from 8640x5760 to 6666 x 4444 to keep a lot of the background. I am thoroughly enjoying the combination of the 135 GM and the A1.