I have a measuring problem with the Lunasix F. I used to handle a Rolleiflex 2,8F with built in exposure meter. It had it's limitations, but it measurements were always ok. Recently I bought an 501C Hasselblad and a Gossen Lunasix F exposure meter. I shot some films with the Hasselblad with the exposure times of the Lunasix F meter (and as a control) with the "old" built in Rolleiflex. I can't explain why, but the measurements of the old Rolleiflex are just better. (the VFx/EF is set on 1, and the ASA is set at the proper film, so the settings of the Lunasix F are ok.). Tanx in advance!