Older manual flash - how to read and set dial ?

[btgc]

Hello, have got that oldie two-AA manual flash for my RF's. Adjustment is made using round dial on side. I understand - select current ISO with arrow and read aperture setting, matching distance on opposite side of dial. To say, I shoot at ISO100 and object is 4.5 metres away, so I read f5.6 on dial and set it on lens.
But wait, dial freely rotates and I can select also distance with arrow. I set arrow to 4.5m and look for aperture setting at ISO100 - alas, it's f11, not f5.6. One of routes is wrong. Which ? I think rather first method is right.

What I miss in my assumptions ?

 

[btgc]

Pitxu, probably I should add - ISO and distance are in aouter, fixed ring (I'm sure anybody knows how this works, but just to be sure). Inside rotates smaller dial with aperture settings and arrow (arrow is opposite to f-stops on that dial). So in second method ISO stays fixed and I look for same ISO100 I used in method1.

What is puzzling me in method2 - aperture settings corresponding to ISO values are illogical, at least for me. To say, at the same 4.5m ISO25 corresponds to f22, ISO200 to f8 and ISO800 to f4. It should be straight reverse, in my understanding !

 

[btgc]

Thanks, this reverts to method1. I just don't believe that people it that times would allow arrow on inner dial reach not just ISO but also distance scale without any reason. Without enlightement I'm restricted to method1 🙂

P.S. oh yes, and sorry to community posting to frong forum, should realize this one is right one.