Some more with the 100-400 and OM1 - still not fully convinced... some sharp shots at close range but with even a modest bit of distance to the target and the quality seems to drop off pretty quickly. The reed bunting for instance - I took 50+ shots and this was the best and it's ok but no better I think. The light was reasonable (f6.3, 1/800 and iso640) and I was about 10 metres away I would say - maybe I am expecting too much, opinions welcome.
Reed Bunting by
Mike Smith, on Flickr
Happy with this one
Herring Gull by
Mike Smith, on Flickr
And this is sharp but at a closer range
Jackdaw by
Mike Smith, on Flickr
This is ok - not great - again at longer range
Wren by
Mike Smith, on Flickr