Precision uvbyCa H \beta photometry of the nearby old open cluster , NGC 752 , is presented .
The mosaic of CCD fields covers an area \sim 42′ on a side with internal precision at the 0.005 to 0.010 mag level for the majority of stars down to V \sim 15 .
The CCD photometry is tied to the standard system using an extensive set of published photoelectric observations adopted as secondary standards within the cluster .
Multicolor indices are used to eliminate as nonmembers a large fraction of the low probability proper-motion members near the faint end of the main sequence , while identifying 24 potential dwarf members between V = 15.0 and 16.5 , eight of which have been noted before from Vilnius photometry .
From 68 highly probable F dwarf members , we derive a reddening estimate of E ( b - y ) = 0.025 \pm 0.003 ( E ( B - V ) = 0.034 \pm 0.004 ) , where the error includes the internal photometric uncertainty and the systematic error arising from the choice of the standard ( b - y , H \beta ) relation .
With reddening fixed , [ Fe/H ] is derived from the F dwarf members using both m _ { 1 } and hk , leading to [ Fe/H ] = -0.071 \pm 0.014 ( sem ) and -0.017 \pm 0.008 ( sem ) , respectively .
Taking the internal precision and possible systematics in the standard relations into account , [ Fe/H ] for NGC 752 becomes -0.03 \pm 0.02 .
With the reddening and metallicity defined , we use the Victoria-Regina isochrones on the Strömgren system and find an excellent match for ( m - M ) = 8.30 \pm 0.05 and an age of 1.45 \pm 0.05 Gyr at the appropriate metallicity .