soap film (n = 1.33) · 50–1200 nm · spectrum mode
each row is 2 nm of film thickness. color from integrated reflectance spectrum — what you'd see, not just the peak wavelength.
orders: m=1 (71–147 nm), m=2 (214–440 nm), m=3 (357–733 nm), m=4 (500–1026 nm). orders overlap increasingly; the wash past ~600 nm is multiple orders mixing.
gap (no constructive wavelength in visible for any single order): 147–214 nm. the morpho butterfly's chitin lamella (~200 nm) sits here — its blue can't come from a single film.
built from builds/thin-film/ · cc