Sycamore leaf disease for ID, please

Sycamore leaf disease for ID, please

Observation - Sycamore leaf disease for ID, please. Description: What has caused the large black area on this Sycamore (Acer pseudoplatanus) leaf? I don't think it's Tar Spot (Rhytisma acerinum)(too early in the season and no yellow area around the black; I suspect the little spots elsewhere on the leaf are the beginni

What has caused the large black area on this Sycamore (Acer pseudoplatanus) leaf? I don't think it's Tar Spot (Rhytisma acerinum)(too early in the season and no yellow area around the black; I suspect the little spots elsewhere on the leaf are the beginnings of Tar Spot.)