In view of the success of the CAM central program on nebulae and HII regions
DCESARSK_HII, we propose to observe in the open time other sources for which
we have good near-IR data and CO maps. Reflection nebulae provide a special
opportunity to study the general interstellar medium. The same physical
processes rule both types of sources but the much more intense radiation
field in reflection nebulae makes their emission much brighter and their
properties perhaps different.
We propose to observe  a few objects with CAM and the CVF in order to
enlarge the sample of nebulae in which the UIB emission features are mapped,
with an emphasis on  different radiation fields (intensity and spectrum).
Complementary data exist on the chosen sources, such as NIR H2 emission and
CO maps. The comparison with the UIB emission is a powerful tool to determine
the geometry of the nebula, and the nature of the different emission regions.
In particular, we aim at studying the existence of PAHs and the variations
in their band and continuum emission in ionized, diffuse and dense gas
submitted to a variety of radiation fields.