I recently purchased an old, but useable, Zeiss Ikon Nettar so that I might dabble in the medium format. I'm about half way though the first roll of T-MAX 100 on the camera when the following came to mind: <p> When using my Canon and the "Sunny 16" rule, a shutter speed of 1/125 would be the order; but with the Nettar the max shutter speed is 1/100. So I guess the heart of the question is "Is ISO 100 film actually made with the 1/125 shutter in mind?" Thus, should I open up half a stop or so on the Nettar for best results? <p> Many thanks in advance.