In article , hinkey@pop.seanet.com says...

>I've been doing some technical photography (i.e., taking pictures of
>machinery in the field) in some wrather tight places which sometimes >makes looking through the viewfinder quite difficult. How useful
>would the right angle attachment be in this situation for my F3?

Quite useful, since it will rotate to any angle (though, if you have
the HP prism, you will need the adapter to get you to the smaller
thread size of the right-angle adapter [which was designed for the
older, smaller eyepiece size]). The magnification is lower, and it
is harder to see the whole field with glasses, though you can use it without glasses since it has a focusing eyepiece. Alternatives would
be the regular waist-level finder, and the sports finder which has
a very large eyepiece, allowing full-frame viewing from a distance
of several inches (I like mine for general shooting, and for placing
the camera in odd locations - I don't need to be right there with
my eye plastered against the camera to see the viewing screen]).
Hope This Helps