[Qgis-user] create polygon: underlying image is covered

[Thomas Recknagel]

I want to vectorize land forms from an ortho image, so I make a new 
polygon shape file and create new objects inside it. When I follow the 
outline of the land form, I have the problem that the new polygon covers 
the underlying layer (it is red and only slightly transparent), so I 
cant see the structures of the ortho image anymore. Is there a way to 
create new polygons, but only have the border of the polygon drawn while 
creating it? I couldnt find such an option in QGIS.