  Context: The Deep Extragalactic VLBI-Optical Survey (DEVOS) aims at
constructing a large sample of compact radio sources up to two orders of
magnitude fainter than those studied in other Very Long Baseline Interferometry
(VLBI) surveys. Optical identification of the objects is ensured by selecting
them from the Sloan Digital Sky Survey (SDSS) list. Aims: While continuing to
build up the DEVOS data base, we investigated how the VLBI detection rate could
be enhanced by refining the initial selection criteria introduced in the first
paper of this series. Methods: We observed 26 sources in two adjacent, slightly
overlapping 2 deg radius fields with the European VLBI Network (EVN) at 5 GHz
frequency on 2 March 2007.The phase-reference calibrator quasars were
J1616+3621 and J1623+3909. The objects selected were unresolved both in the
Faint Images of the Radio Sky at Twenty-centimeters (FIRST) survey catalogue
and the SDSS Data Release 4. Results: We present images of milli-arcsecond
(mas) scale radio structures and accurate coordinates of 24 extragalactic
sources. Most of them have never been imaged with VLBI. Twenty-two compact
radio sources (85% of our initial sample) are considered as VLBI detections of
the corresponding optical quasars in SDSS. We found an efficient way to
identify quasars as potential VLBI targets with mas-scale compact radio
stucture at >1 mJy level, based only on the FIRST and SDSS catalogue data by
applying simple selection criteria.
