Does anyone else remember the days in the 50's and 60's when many cameras and exposure meters had EV scales printed on them, so that you could, for example, dial in a higher shutter speed and then just turn the aperture ring until you got the same EV number lined up as the meter indicated? No need then to understand the philosophy of f-stops, just know you needed to twist the ring until it matched, and away you go. Of course, that almost mandated that people thought in terms of shutter-priority rather than aperture priority!
I tend to agree with those who are saying that there is no need to retain the maths-based labelling of lens apertures for consumer, or indeed professional lenses, if a common replacement system is adopted. But, what system do we adopt? A reciprocal system such as we are all used to with shutter speeds? So, for example, the scales would read: f1.4 = .7142857, or 71 for simplicity f2 = .5, or 50 f2.8 = .3571428, or 36 f3.5 = .2857142, or 29 f4 = .25, or 25 f5.6 = .1785714, or 18 f6.3 = .1587301, or 16 f8 = .125, or 13 f9.5 = .1052631, or 11 As the scales approach smaller apertures, the simplified values become less differentiated, but still usable, so that: f22 = .0454545 or 5 f32 = .03125 or 3 The only problem may lie with intermediate values, where converting to an integer by multiplying by 100, as I have done, may not allow sufficient accuracy. And I have to ask, why is there a problem with understanding ascending aperture values, when, in most viewfinder or LCD displays, the shutter speeds are not shown as 1/n but as n, so that 1/125 would appear to be half the value of 1/250? And of course, the problem of the changeover period, when all of the old equipment would have inconsistencies with newly produced gear, would last for a very long time, and cause great confusion! John Coyle Brisbane, Australia On Monday, November 25, 2002 7:15 PM, Bob Walkden [SMTP:[EMAIL PROTECTED]] wrote: > > You may well understand the relation between the size of the hole and > depth of field, but it doesn't mean the hole has to be labelled in > f-stops. Labelling it in a simpler way wouldn't change the physics at > all, but it might make it all easier for beginners to understand > instead of having to do that weird brain switch because bigger holes > have smaller numbers. > > --- > > Bob >
