In his lecture on Bruce Conner’s film REPORT, (which I encourage you to read here) he says..

With 8mm you have all the immediate potentiality of the powers of a sketch. You have that brevity, the quickness, the lightweightedness of the camera, that expendability of it. Nothing in the area of 8mm will ever be in the consideration for prizes or awards.

In fact, even in this classroom we have to go a little out of our way. The projector sits on the floor. It will be a little like home movies. The lights will be dim, you will have to strain a bit to see it—the image is small—
expendable, in every sense of the word.
You might almost use as a metaphor that brooding and struggling with 16mm, with all of its technical resources, is like creating an oil painting. Conner struggled between these two concepts—a sketch or, say, a masterpiece—in making the 16mm version. The 8mm is the immediate capturing of his immediate feelings at this point. The 16mm is thoroughly worked through.

From a lecture by Stan Brakhage at the School of the Art Institute of Chicago, April 1973