We present the Capodimonte Deep Field ( OACDF ) , a deep field covering an area of 0.5 \deg ^ { 2 } in the B , V , R optical bands plus six medium-band filters in the wavelength range 773–913 nm .
The field reaches the following limiting magnitudes : B _ { AB } \sim 25.3 , V _ { AB } \sim 24.8 and R _ { AB } \sim 25.1 and contains \sim 50000 extended sources in the magnitude range 18 \leq R _ { AB } \leq 25.0 .
Hence , it is intermediate between deep pencil beam surveys and very wide but shallow surveys .
The main scientific goal of the OACDF is the identification and characterization of early-type field galaxies at different look-back times in order to study different scenarios of galaxy formation .
Parallel goals include the search for groups and clusters of galaxies and the search for rare and peculiar objects ( gravitational lenses , QSOs , halo White Dwarfs ) .
In this paper we describe the OACDF data reduction , the methods adopted for the extraction of the photometric catalogs , the photometric calibration and the quality assessment of the catalogs by means of galaxy number counts , spectroscopic and photometric redshifts and star colors .
We also present the first results of the search for galaxy overdensities .
The depth of the OACDF and its relatively large spatial coverage with respect to pencil beam surveys make it a good tool for further studies of galaxy formation and evolution in the redshift range 0–1 , as well as for stellar studies .