Re: Pop Photo Resolution Lines Per ? MATH

[Roger Eichhorn <eichhorn@xxxxxx>]

I hope behind the smirking, you got my main message!

Roger

On 14 May 2008, at 10:22 PM, Alexander Georgiadis wrote:

> Yeah, I'm sure we all pricked up on that and smirked.
>
> On Wed, May 14, 2008 at 7:40 PM, Roger Eichhorn <eichhorn@xxxxxx>  
> wrote:
>
> > Okay, someone is going to point out that the reciprocal of 91.44 is  
> > 0.01094
> > (to five significant figures), not 0.1094 as I wrote.  I might as  
> > well do it
> > myself.  My bad!
> >
> > Roger
> >
> >
> > On 14 May 2008, at 5:14 PM, Roger Eichhorn wrote:
> >
> > It's handy to regard unit conversions as though the units were  
> > algebraic
> > > symbols.  They can then be cancelled.  For example  2.54 cm/in X  
> > > 12 in/ft =
> > > 30.48 cm/ft.  Inch is in the denominator of the first and in the  
> > > numerator
> > > of the second.  The two cancel.  Take the last result and multiply  
> > > by 3
> > > ft/yd and you get 91.44 cm/yd as ft cancels.  Take he reciprocal  
> > > of this
> > > last result and you  get 0.1094 yd/cm.  It avoids a lot of errors.
> > >
> > > Roger
> > >
> > > On 14 May 2008, at 4:11 PM, PhotoRoy6@xxxxxxx wrote:
> > >
> > >
> > > > So Jim, Michael is right
> > > > ( Further, your math is wrong. 2100/25.4 = 82 lines, which  
> > > > translates
> > > > into
> > > > 41 lp/mm. Keep in mind that these tests are at full contrast  
> > > > (i.e. Black
> > > > lines
> > > > on white background) so comparison to normal 50% MTF is difficult.
> > > > )
> > > > which makes digital APS-C no where near to 35mm film in terms of
> > > > resolution.
> > > > Thanks,
> > > > Roy
> > > >
> > > >
> > > >
> > > > In a message dated 5/14/2008 8:48:08 A.M. Eastern Daylight Time,
> > > > jimth@xxxxxxxxxxxxxxx writes:
> > > >
> > > > Your understanding of conversions between metric and  imperial
> > > > measurements
> > > > is decidedly limited.
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > > **************Wondering what's for Dinner Tonight? Get new twists  
> > > > on
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> > > > favorites at AOL Food.
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>
>
> --
> Alex Georgiadis