What’s this Bird?

I am not very good at birds. There will always be someone with more knowledge than I. As a rule birds move very fast and that makes them difficult for me to photograph. But back in early June this small bird was hopping uncertainly along the dirt path beside a barley field just ahead of me. It made a some practise flights a few inches from the ground and then scurried into the wayside vegetation. It paused long enough for me to photograph. I think it is an immature female Blackcap (with the lovely scientific name of Sylvia atricapilla). Does anyone else have other ideas about its identification?