We have carried out multicolor (UBVI) CCD photometry for more than 140
0 stars (13.5 < V < 21.5) in a 6' x 6' field of the globular cluster M
30. We find the main-sequence turnoff at V-TO, = 18.65 +/- 0.05, (B-V)
(TO) = 0.46 +/- 0.03, (V-l)(TO) = 0.62 +/- 0.04, and (B-I)(TO) = 1.08
+/- 0.05 (errors include uncertainties of the photometric zero points)
. From a comparison of the two-color (U-B)-(B-V) diagram for the clust
er with the similar diagram for NGC 6397, a reddening value E(B-V) = 0
.078 +/- 0.043 is derived for M30. We have analyzed the positions of m
ain-sequence stars, subgiants, and giants in the (U-B)-(B-V) diagram a
nd revealed some deviations from theoretical predictions and some diff
erences compared with NGC 6397. Our comparison of the color-magnitude
diagram with isochrones shows that the cluster is approximately as old
as NGC 6397. The isochrone fit is not quite consistent when using dif
ferent color indexes. We have also found some deviations from the obse
rved shape of the main sequence for existing theoretical isochrones. T
he upper limit for binary population in the studied cluster field (inc
luding visual double stars) is estimated as similar to 5% at r similar
to 6' from the cluster's center.