Globular clusters towards the bulge can be used as tracers of the Galaxy subsystems in that direction. In recent years CCD and infrared detectors allowed a great improvement in colour-magnitude diagrams of clusters in such crowded and reddened regions. Among the main questions concerning the bulge is the possible presence of a bar (Blitz & Spergel 1991). A possible way to test the scenario of bulge being identified with a bar, is to determine characteristics of globular clusters located on opposite sides of the Galactic center. In the present paper we study NGC 6380 and Terzan 12, which are suitably located for this purpose in terms of galactic coordinates.
The globular cluster NGC 6380, also known as Tonantzintla 1,
Pismis 25 (Pismis 1959), GCL 
, BH 233
(van den Bergh & Hagen 1975),
and ESO 
(Holmberg et al. 1978), has
coordinates
,
(
, 
).
Terzan 12 (Terzan 1971a) was renamed as Terzan 11
at the publication of a second list by Terzan (1971b), because
in the first list Terzan 11 was actually the same as Terzan 5 (Terzan
1968) (see also King 1972). In Terzan
(1971b) a new Terzan 12 appeared which is in fact NGC 6256.
We adopt the designation Terzan 12 as given in Terzan
(1971a). It is also designated as 
, GCL 
. The coordinates are
,
(
, 
).
Previous studies provided the following information on NGC 6380:
Malkan (1982) derived E(B-V) = 1.4 from integrated
infrared photometry, and Zinn (1985), based on the same data,
estimated a metallicity of 
. By means of the bright
giants method, Webbink (1985) estimated a Horizontal Branch
(HB) level of 
which, combined to a
reddening of E(B-V) = 1.38 deduced from Malkan's data, led to
a distance from the Sun of
. Webbink indicates a metallicity of 
.
Concerning Terzan 12,
by means of the bright giants method Webbink (1985)
estimated a horizontal branch level of 
which he marked as very uncertain. He also presents a reddening
of E(B-V) = 1.57 that was estimated from the modified cosecant
law, and he derived a distance from the sun of 
.
Trager et al. (1995) studied cluster structure for a large sample, deriving a concentration parameter of c = 1.55 for NGC 6380, and they did not exclude the possibility of a post-core-collapse morphology. Terzan 12 (therein called Terzan 11) is not concentrated (c = 0.57).
No Colour-Magnitude Diagrams (CMDs) are available for these two clusters.
We present V, I photometry for NGC 6380 and Terzan 12, using the ESO NTT telescope, and determine reliable cluster parameters.
In Sect. 2 (click here) the observations are reported. In Sect. 3 (click here) the CMD morphology and cluster parameters are discussed for NGC 6380. In Sect. 4 (click here) a similar analysis is given for Terzan 12. In Sect. 5 (click here) we discuss the results obtained for these two clusters and neighbouring ones in the context of the bar/bulge question. Finally, concluding remarks are given in Sect. 6 (click here).