Black Ice (1994):
Senses of Cinema considers him one of the great directors and has an article here. There are numerous resources linked from this page. UBUWEB has video and audio of Brakhage at their site. The Brooklyn Rail has an article. The Creators Project has some of his work embedded in their article and says
Working in a variety of formats, Brakhage’s films are exceedingly expressionistic abstractions, ranging from amorphous collages of vaguely superimposed imagery of his life and family, to direct manipulation with film stock scratched and splattered with paint.My Mind's Eye has an interview from when Brakhage was 60 in which he says, "one of the most vibrant ways to be dedicated to the arts is to be highly suspicious of every historical or inherited aspect of it". An article at Criterion's site says
Unlike traditional filmmakers, Brakhage wanted to divest consciousness from its representative trappings to allow for an unfettered vision of the subjective experience.
In his best-known pronouncement, he summons the movie viewer to “imagine an eye unruled by man-made laws of perspective...How many colors are there in a field of grass to a baby unaware of 'Green'? How many rainbows can light create for the untutored eye?” Although he readily admits that any actual return to a state of “innocent,” childlike vision is impossible, lhe persistent project throughout his vast oeuvre has been to guide the eye in a journey of “untutoring,” using every possible cinematic tool as leverage for that journey.Poets.org says, "Through his insistence on exploring the bounds of perception, poets and other artists felt deeply connected to Brakhage’s work." The Guardian obituary says
For Brakhage, the goal of cinema was the liberation of the eye itself, the creation of an act of seeing, previously unimagined and undefined by conventions of representation, an eye as natural and unprejudiced as that of a cat, a bee or an infant.