[OM] aperture ring question

[William Clark]

I have a brief question.  I have sitting in front of me a Vivitar 28 2.5 and
an Olympus 28 2.8.  The aperture ring on the Vivitar can be set IN-BETWEEN
aperture values while the Olympus will only set itself at the specific
f-stops.  A 35mm Vivitar also does this.  Does anyone know why Vivitar chose
to allow a more flexible aperture setting?  Is this really more flexible?  I
have never really thought about it before.

Thanks,
-Bill