The lens has no effect on picture noise.
Not in your control but it's a shame the light is behind the Robin.
However, had you used spot or partial metering then the exposure would have been better.
thanks for the advice mate. i know.. if i went the other side of the robin, i would have had to go down hill, and wouldnt have been on the same level as it. it did sit there patiently for 5 minutes while i took a few snaps though!
so what does metering actually do?