Aperture photometry of all stars in the field surrounding star BD+32 3739 (HD 331891). RINGO2 data are taken from observations of this standard star on all photometric nights between 2012 June 3 and 2012 October 26. The eight RINGO2 images at each epoch are coadded to create an unpolarized image. The comparison IO:O data are a single epoch, obtained on the night of 2013 September 4. All numbers are simple instrumental magnitudes calculated as ﹩-2.5\,{\mathrm{log}}_{10}(\mathrm{counts})﹩. The left panels compare RINGO2 to IO:O g′ filter, the central column is RINGO2 and IO:O r′, and the right panels show IO:O i’. The top row directly compares the instrumental magnitudes from the two instruments. The middle row plots the magnitude difference between RINGO2 and various IO:O filters, effectively the zero-point difference between the instruments, which is shown to be independent of magnitude for filter ﹩r^{\prime} ﹩. The bottom row derives zero-point color transformations between the RINGO2 filter and the various SDSS-type filters. Again, ﹩r^{\prime} ﹩ is seen to be a good match to RINGO2 without applying any color correction. The clumpy distribution of points is caused by a single IO:O observation of each star, which is compared to 54 epochs of RINGO2 observations.