The last reviewer said he sprayed canned air onto the brush!! Anyone who knows anything about cameras knows you should NEVER spray compressed air: use just an air rocket (a.k.a. "torpedo"). Of course spraying a chemical onto the brush and then brushing something will "leave streaks" of that chemical.
I use this brush for Phase One digital backs, when using the air rocket is insufficient and I don;t need to use the official Phase One cleaner (which is more time consuming). It picks up dust great!
[0 of 1 customers found this review helpful]
I blew canned clean air on the brush to clean it, waited a few seconds, and then lightly brushed the sensor. The brush left dust on the sensor and added streaks to the sensor. The streaks and remaining dust showed up in my pictures. By adding streaks, the sensor brush made the problem worse than when I started. I wish I had never bought it.