Hobby or Merlin?

Sorry for the terrible photo. I didn't want to disturb the bird any more than necessary. But it's chosen the top of the house as a roost for the past few days. Pellets vary in size but are no bigger than a bottle cap so far. Yellow legs. Facial markings appear more brown face on. Brown body with more of a beige underside. Back appears speckled when sleeping. Haven't heard it call. (Location: Suffolk/Norfolk border)