I have an F1 and for the money I have in it...its ok. It was a re-furb I got for $50 from Chrony back when they sold re-furbs.

Not the greatest but for a very basic chrony it works. Best if the sun is shinin and you're shootin mid day. I have shot arrows, bullets, pellets and even thrown a few rocks thru it. The only thing I haven't done is shoot it.