The main problem is that alll details are extruded vericaly so if I have a small horizontal hole in the model it will get filled by the layers on top. Or the nose of a figurine gets all over the lower part of the face.I carefully chosen exposure time (3-4 seconds for the acer located around 18cm from the print area) and any smaller than this and the layers will not stick.
Am using a MakerJuice SUB green resin and have a feeling that because it is quite translucent the light from any layer cures little by llittle the resin below. Layer size is 0.1 mm.