strange idea....

[Christian Hofmann]

On Wed, 22 Dec 1999 13:04:28 +1030
"Budweiser [FTS]" <budfts at eisa.net.au> wrote:

> I just got up and opened the curtains to my bedroom, and i looked through the
> fly
> screen. About 2 feet away from the fly screen is another screen / blind
> (shade cloth,
> you can see through it) Anyway, you see this "beating" effect of the 2 grids
> cancelling
> and reinforcing difference patterns (if i remember my yr 11 physics, Newton's
> rings?!).
> 
> Well, I figured I was looking at a really complex filter. The closest filter
> i could think of
> that might have a similar characteristic (if u could even compare light and
> audio filters!)
> to a comb filter. Depending on the angle you look at the screen, and how
> close you are,
> all manor of crazy patterns are created before your eyes!
> 
> I wanna know what this would sound like dammit!!!!! 

Hi Bud,
it's not really a filter, but indeed it's quite similar to the beating
between multiple (slightly detuned) oscillators. 

The difference is that detuned oscillators show a beating in time, while
the double fly screen shows a beating in space (or in viewing angle to
be precise), aka moiree. And it looks more complex since it is two
dimensional.

cu & merry Xmas
Xtian