I can't see the point in changing from an aperture value system that means something, to an arbitrary system with no arithmetical connection between settings and to the physical attributes of the lens.
To a beginner any progression of numbers will be as mysterious as any other, so there is no advantage to be gained. But advanced photographers would lose a valuable facility, i.e. the ability to calculate exposure adjustments for any lens and for any format of camera or enlarger, with any light meter at any magnification ratio (e.g. close-up extension). And probably a lot of other technicalities that escape me at the moment. Long live the aperture ring on lenses, especially with the present numbering. Regards, Anthony Farr ----- Original Message ----- From: "John Coyle" <[EMAIL PROTECTED]> > 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 > >
