Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@y..., "Austin Franklin" <darkroom@i...> wrote:

> Roy,
> 
> I do read all your posts!  I just don't have the time right now to devote to
> responding.  I believe I've simply stated my case, and it should stand on
> it's own.  I do want to write this up, as I feel it is important enough to
> devote the time to it when I have the time.  I have discussed this very
> topic with others (far smarter than I am, and also professionals in the
> field), and they, too, view life the same way...so it appears the only thing
> I'm doing is attempting to change your mind, and it appears you don't want
> to change it.
> 

That last sentence pretty much works equally well either way.  I could
easily have written it also, word for word.  That's the dilemma.

> 
> > Roy:  Well its really starting to look good now.  In fact
> >       it turns out that there really are numbers on all
> >       the marks.  But, they sure don't look like we
> >       expected.  Here's what's written on the marks:
> >
> >       1, 1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22, 32.
> 
> Ah, but that has to do with the area of a circle...vs radius...  You could
> very well re-mark those anything you want...like relative area, then it
> would be marked 1, 2, 4 etc. (as a divisor), or 1, 1/2, 1/4 etc.

Certainly, could have. They would still be exponential. They would look exactly
like the shutter numbers.

> 
> Area = pi * r**2
> 
> For a 50mm lense, f1 has an opening of 50mm...and the area (which is
> directly proportional to the amount of light let in) is 1963 sq mm.  f1.4,
> which is 1/2 the amount of light is 1001 sq mm, f2.0 is 490 etc.
> 
> > Well obviously the rulers are on my lens,  The first one
> > is the aperture ring and the second one is the shutter
> > speed.  I wanted to illustate how different an exponential
> > series is from a linear series.
> 
> But they aren't different...they ARE both linear.  One is merely part of an
> equation that represents the actual area of the opening...it's merely a
> representative number and could have been the actual area for that matter!

Are you really going to call that series of aperture numbers
and the shutter numbers, LINEAR??  That's a serious problem!
I can't imagine how a claim like that is helping your cause.

The numbers themselves are exponentially varying. 
They measure real physical parameters that are exponentially varying.  
The lens is specifically designed for the exponential variation, explicitly
because the response of either film or the eye requires the
light intensity to be exponentially varying to produce evenly spaced
intervals in our perception.

> 
> Regards,
> 
> Austin

Roy