Soot and whitewash.
Fomapan 100 is only a 100EI film in ID-68/Microphen, that's according to Foma's own datasheet, I've always shot it at 50EI developed in Pyrocat HD with excellent results.
You need to realise LF lenses have vert shallow DOF, lenses need stopping down well, and movements like front tilt would help here.
Ian