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Hi Hewitt
My brief understanding is simply that it is a rumor ...(generally not true).
I think it is an Australian term..
I find it somewhat vexing when chaps from different cultures toss out
strange words...without giving a quick nod as to what the word means..to
them.
On this note I think I will cross the line.. (go from Cda to USA)
Irv

-----Original Message-----
From: navlist-bounce@fer3.com [mailto:navlist-bounce@fer3.com] On
Behalf Of Hewitt Schlereth
Sent: Monday, June 14, 2010 5:09 PM
To: NavList@fer3.com
Subject: [NavList] Re: NG's "Midnight Fun"

Peter -

A "furphy"? I like the sound of it; but what is it?

Hewitt

On 6/14/10, Peter Fogg  wrote:
>
>
> George Huxtable wrote:
> >
> > As that posting confused distortion with perspective, it had little
> > relevance to the matter in hand.
> >
>
> No.  George is wrong.  I have been careful, unlike George himself, even in
> his latest post, to distinguish apparent distortion, such as the effects
of
> perspective, from other distortions caused, by example, by the
shortcomings
> of lenses.
>
> >
> > This question takes on a bit of importance because postings appear on
this
> > list, quite often, from proponents of the use of cameras for making
> > celestial measurements. The geometrical distortions discussed here, that
> > arise from portraying a spherical surface on to a plane array, add
serious
> > complications to interpreting measurements, and deriving scale factors;
> > complications which are often neglected.
> >
>
> As in a lot of stuff you post, George, you confuse the theoretical with
the
> practical.  The examples of "use of cameras for making celestial
> measurements" that's I've seen here involve the sun's image near the
centre
> of the image field.  In this case there is nothing, in any practical
sense,
> to worry about in respect of what may happen to other parts of the image
> towards the edges of the field, from whatever cause.  Once again, like so
> many of these you trumpet so loudly so often as matters of grave concern,
> its just a furphy.
>
>

   

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