ngc3242_b.fits
EXPTIME =                  10. / exposure time (seconds)
FILTER  = ' (2) B (375-490)'   / Filter

ngc3242_r.fits
EXPTIME =                  10. / exposure time (seconds)
FILTER  = ' (4) R (570-690) '  / Filter

ngc3242_v.fits
EXPTIME =                  10. / exposure time (seconds)
FILTER  = ' (3) V (490-580)  ' / Filter