The gnomon point of my sun dial is also very thin. In order to observe the
shadow point as exactly as possible, I use an old and simple trick: by
touching the gnomon-point with one of my fingers, the semishadow almost
disappears
locally and I can better observe the exact location.
Jos Kint
:
AW: Shadow caster
I thought so!!!
Actually: Inside the house a
little sunspot is much more fun than a tiny dizzy and
diffuse shadow point
Reinhold
Several times, there have been discussions about how to improve the shadow cast
by a point nodus. I partially recall some conclusions regarding the optimum
diameter vs, throw length, and some thoughts about adding an annular ring to
take advantage of diffraction.
Can anyone help remind me?
An: sundial@uni-koeln.de
Betreff: Shadow caster
Several times, there have been discussions about how to improve the
shadow cast by a point nodus. I partially recall some conclusions
regarding the optimum diameter vs, throw length, and some thoughts about
adding an annular ring to take advantage
_
From: Reinhold Kriegler [mailto:reinhold.krieg...@gmx.de]
Sent: Sunday, March 04, 2012 11:51 AM
To: 'Dave Bell'
Subject: AW: Shadow caster
☺ I thought so!!!
Actually: Inside the house a little sunspot is much more fun than a tiny dizzy
and diffuse shadow point…
Reinhold
From: Dave Bell db...@thebells.net
To: 'Reinhold Kriegler' reinhold.krieg...@gmx.de
Cc: sundial@uni-koeln.de
Sent: Sunday, 4 March 2012, 20:33
Subject: RE: Shadow caster
I agree that a bright sun spot would be nice, but I don’t want to black out
much of the window.
Unfortunately
diameter of the sun. As a start, check the Compendium 9-4
Dec 2002 for articles by Gianni Ferrari, Bill Walton and John Carmichael.
--
From: David Bell db...@thebells.net
Sent: Sunday, March 04, 2012 9:50 AM
To: sundial@uni-koeln.de
Subject: Shadow
the winter, but a good cleaning did
little to improve clarity; just made the blotchiness more evident.
Dave
_
From: Roger Bailey [mailto:rtbai...@telus.net]
Sent: Sunday, March 04, 2012 2:59 PM
To: John Lynes; Dave Bell
Subject: Re: Shadow caster
It is likely worse than
