Łukasz Czekała on violin and Kuba Puch on trumpet, and with Jakub Urbańczyk on tuba and Jarosław Spałek on trumpet respectively. The Oleś brothers add other instruments as well, with Marcin playing double bass, piano, keyboards, acordeon and acoustic guitar, and Brat playing drums, percussion, gongs, tabla, marimba piano, keyboards, compositions
The end result is quite atmospheric but most of the time nothing more than just that : nice yet non-committal sound to accompany images. And that is of course partly the objective of the original compositions.
That being said, some of the tunes are really nice, almost in the same league as Evan Lurie, or even John Zorn's music for films : quite accessible, yet fresh minimalist pieces on which a few well-chosen sounds create a sad, or eery, or introspective, or menacing environment. That these environments are created by a few brush strokes by a few instruments is a stellar achievement. The downside is that like with all soundtracks, there is no expansion or exploration: the music is simple by definition : a theme needs to be set, easy in the ear because a first listen is all you get with your main attention going to the visual movements, and repeated several times to get entrance in your less attentive part of the brain.
A nice stylistic exercise, yet for the real thing, check out their real Duo album.