  We use two-band imaging data from the Advanced Camera for Surveys on board
the Hubble Space Telescope for a detailed study of NGC1533, an SB0 galaxy in
the Dorado group surrounded by a ring of HI. NGC1533 appears to be completing a
transition from late to early type: it is red, but not quite dead. Faint spiral
structure becomes visible following galaxy subtraction, and luminous blue stars
can be seen in isolated areas of the disk. Dust is visible in the color map in
the region around the bar, and there is a linear color gradient throughout the
disk. We determine an accurate distance from the surface brightness
fluctuations (SBF) method, finding m-M = 31.44\pm0.12 mag, or d = 19.4\pm1.1
Mpc. We then study the globular cluster (GC) colors, sizes, and luminosity
function (GCLF). Estimates of the distance from the median of the GC half-light
radii and from the peak of the GCLF both agree well with the SBF distance. The
GC specific frequency is S_N=1.3\pm0.2, typical for an early-type disk galaxy.
The color distribution is bimodal, as commonly observed for bright galaxies.
There is a suggestion of the redder GCs having smaller sizes, but the trend is
not significant. The sizes do increase significantly with galactocentric
radius, in a manner more similar to the Milky Way GC system than to those in
Virgo. This difference may be an effect of the steeper density gradients in
loose groups as compared to galaxy clusters. Additional studies of early-type
galaxies in low density regions can help determine if this is indeed a general
environmental trend.
