Cleaves a number of carotenals and carotenols in the all-trans configuration at the 15-15' double bond producing retinal or retinol, respectively. Also shows activity toward lycopenals and the corresponding alcohols. Does not cleave beta-carotene or lycopene. all-trans-8'-apo-beta-carotenal + O2 = (2E,4E,6E)-2,6-dimethylocta-2,4,6-trienedial + all-trans-retinal Binds 1 Fe(2+) ion per subunit. By high light. Belongs to the carotenoid oxygenase family.