I am looking to film near a window. I was wondering if there was a certain material that can take the sun light source and spread it evenly and wider. I find that a diffuser it isn't enough is there another type of material that would spread and expand it even?
You did not mention: size/area, permanent/temporary, budget, etc. etc. So, in the absense of any practical constraints, letting my imagination run wild....
I would investigate hanging a row of round acrylic ("Plexiglas") rods like a curtain which would serve rather like a big amorphous "Fresnel lens".
Else, you could use the traditional "brute-force" method used by big-budget production companies:
- Giant lamps outside the window focused through the opening. They commonly use expensive (and very bright) HMI lights for "punching through" sunlight levels.
- Big reflectors that catch extra sunlight and reflect it in through the window. Metalized reflective fabric stretched on a big frame