How do clear and diffuse sample spectra compare on a diffuse transmission accessory?

The graphs at the top shows the measured results on the glass filter and opal glass. As a transparent sample such as the glass filter produces no diffuse transmitted light, the diffuse transmittance is approximately 0 %. A translucent sample such as opal glass, on the other hand, produces almost only diffuse transmitted light such that the transmittance is approximately 40 %. This does not differ significantly from the total light transmittance value.

The samples are displayed at bottom center.