its actually quite sensitive and I have a hard time keeping it green as the camera moves slightly, I think its more sensitive than my K110D's 'green hexagon' focus indicator. if there isn't enough contrast for it to identify focus it will light up both red arrows (see pic of manual in first post) I have tested only 2.8 and 3.5 lenses on it (go figure as those are the two selections) smc-A 35mm 2.8 and S-M-C Takumar 135mm 3.5 but regardless of selected aperture it seems to work well. I can also rely on the audible tone to help as well. though in all honesty my eyesight is well enough that the split-image focusing screen is more than enough to get proper focus.
here she is decked out in Takumar
and here she is right after I got her, setup beside my workhorse.
