Spectrum for model he6p0 at 428 d after explosion (thick black line; Dessart et al., in prep.) together with the normalized LSST ugriz filter transmission functions (the y filter is not included in that figure). The thin black line is the model spectrum for a redshift of 0.2. For redshifts of ∼0.1 the photometric measures would be hard to use since [O I] λλ 6300,  6364, and [Ca II] λλ 7291,  7323 fall between filters.