FASTAR spectroscopic and photometric predictions. Blue lines show to the FASTAR SSP models for a 10 Gyr old, solar metallicity population. In light blue, the FASTAR photometric model is based on the BOSZ theoretical stellar library and can be convolved with any set of photometric filters (exemplified by the different transmission functions in grey) to generate photometric predictions. In addition, the spectroscopic side of FASTAR (dark blue line) combines the MILES (empirical) and BOSZ stellar libraries to generate models oriented toward detailed stellar population analyses.