You know it's going to be a good day when you open the blinds and spot something new (first I've seen there) in your garden so you dash to the tripod and dismount your camera, take the lens cap off, turn it on, dash back to the window, set the ISO and the Blackcap is still there for the photo.
Great find. I've had them on and off for a few years now. This year there was a male on the feeders for most of the winter. A female turned up a couple of months ago. They appear to have abandoned the feeders for now but are still around. I am positive they bred last year, in or around the garden, and are doing so again. They are lovely birds.