[Daniel_Champion]

I also used the sunny 16 rule as a starting point, but my rule was slightly different, but the same....
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f/16 at ISO100 with 1/100 sec shutter
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it introduced a bit more understanding when using Manual setting

Yes DerMc is exactly the same rule, but back in the days old cameras had shutters speeds like 1/60 ; 1/125 ; 1/250 ... at least the cameras I know, so you should always use the nearest shutter speed number to match the film you are using as you said!