Saw three shorts from Zelimir Zilnik and two from Karpo Godina from the late sixties, early seventies, that could be classified as belonging to the then much-maligned "Black Film" movement.

The three by Zilnik (Lipanjska gibanja (1969), Nezaposleni ljudi (1968 ) , Crni film (1971) with camera by Godina) were early efforts to show poverty and homelessness in Yugoslav society (a fact that was being denied by the government), and his attempts to start dealing with this conciously through the usage of film. A kind of wake-up cry for himself and probably other filmmakers. They were quite interesting, but more as documents of their time and of Zilnik than as films per se.

The two by Godina (Gratinirani mozak Pupilije Ferkeverk (1970), Zdravi ljudi za razonodu (1971) - he photographed, edited, directed, wrote and produced them himself with the help of other members of his team) were more allegorical, and tried to create an impact through the opposition and interrelation of the topic presented and the use of music, editing and framing. The photography is both times excellent (as can be expected by Godina), but the films were imo lacking a bit of substance, (or were maybe just too cynical for my taste).
Both shorts were forbidden. Zdravi ljudi za razonodu because it ridicules the possibility of different ethnic groups living peacfully together in the autonomous region of Vojvodina, while Gratinirani mozak Pupilije Ferkeverk was declared "decadent".

Overall these experimental outings seemed to me on more or less the same qualitative level, with Zilnik's concentrated more on the subject matter and Godina's on its (re-)presentation. Structuring was created primarily through editing and - with Godina - framing. 

I've also seen two films by Karpo Godina (which he directed)last year on slovenian TV, as part of the 100 years of slovenian cinema series (unfortunately they were also the only films I saw). 
The first Rdeci boogie (1982) is somehow already a "classic" slovenian film, that deals with a young travelling band of musicians that are supposed to heighten the spirit of the rural workers through music. It's set in the 50s shortly after the war, and shows the repression of the people under the dictatorship in a seemingly lighthearted and casual but finally very effective way. Comes with a recommendation.
The second, Umetni raj "Artificial Paradise" (1990) is about Fritz Lang's stay in Slovenia during the First World War. In the background story Lang reminisces this stay from his new-found home in Hollywood during the thierties. The film is interestingly constructed, but imo ultimately failed as a whole. The history lesson and characterstudy was overall too heavy-handed to enjoy. 
The most impressing is his camerawork, which can be imo compared with some of the best around the world. His way of lighting, and use of space and time can create astonishing effects. He prefers long deep-focus shots and plan-sequences. Both films are very slow, and on the surface not much seems to be happening, but the camera acts as observer and commentator. Another film he has photographed and I've seen is Radio.doc (1995) which was made for TV (you can find a short review by me in the slovenian films thread).