We report the photochemistry of two ring-open isomers, namely TTC and TTT, of a bidirectional photoswitchable spiropyran, 6,8-dinitro-1',3',3'-trimethylspiro [2H-1-benzopyran-2,2'-indoline] (6,8-dinitro BIPS). Both isomers are capable of ring closure after excitation with visible fs laser pulses, as disclosed by pump-wavelength-dependent transient absorption experiments in the visible spectral range. The main isomer TTC has its maximum absorption at 560 nm, whereas the minor isomer TTT is red-shifted (600 nm). The excited-state lifetimes differ strongly (tau approximate to 900 Ps for TTT and tau approximate to 95 ps for TTC), nevertheless the quantum efficiencies for ping closure (40% for TTC and 35% for TTT) and isomerization.(1-2% for TTC and 1-2% far TTT) are comparable. With regard to the bidirectional photoswitching capabilities, 6,8-dinitro BIPS is the first molecular switch based on a 6 pi-electrocyclic reaction where both ring-open isomers are capable of ring closure.