Help with Bronica ETRs Prism Finder E

I picked up a Bronica ETRs Prism Finder E, non metering. What I need to know is whether the screw behind the rubber eye cup is an adjustment for a diopter. If so, any information which way is posives/negative and best method for correct for eye sight. I know know it is easy for the AE III prism finder.

Thank you all for your help.

Edward

Not to adjust but to hold a fixed eyepiece, there are several graduated eyepieces for that type of prism, for more information refer to: http://www.tamron.com/bronica/prod/etrsi_eye.asp
Regards
Max

Max,

Thank you for your help.

Edward