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Re: Streamer colour
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- Subject: Re: Streamer colour
- From: "Tesla list" <tesla@xxxxxxxxxx>
- Date: Sun, 27 Mar 2005 20:09:50 -0700
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Original poster: Mddeming@xxxxxxx
Hi Bob, All,
The problem of "true" color is more philosophical than physical. By
one definition, color is the response of the optic nerve to certain energy
photons. In this view, color does not exist if there is no eye to see it.
Color can also be defined by the specific wavelengths present in the
spectra. This definition is more amenable to objective analysis.
Has anyone tried taking spectrographic pictures of arcs and streamers with
either an analog or digital spectroscope, and comparing them this way? It
seems that it would be easier to agree on the numbers than on whether
something "really is" what it "appears" to be.
In a message dated 3/27/05 11:42:29 AM Eastern Standard Time,
Original poster: "Bob (R.A.) Jones" <a1accounting@xxxxxxxxxxxxx>
Here is a link to a pic of a discharge. The exposure time appears to be
short as it was taken in day light.
Note the discharge even close to the top load is violet when it is spread
out by the banjo effect.
It appears as if the whiteness of many discharge pics is caused by
saturation effects in the image.
This may even be true when viewed by eye.
All some one has to do is take some pics at a high F number and perhaps with
a neutral density filter.
Don't compress the image. Check if the pixels in any of the color channels
are saturated. If they are it does not represent the true color.
Try again with less exposure or a more dense filter
Robert (R. A.) Jones
A1 Accounting, Inc., Fl
407 649 6400
----- Original Message -----
From: "Tesla list" <tesla@xxxxxxxxxx>
Sent: Saturday, March 26, 2005 6:10 PM
Subject: Re: Streamer colour
> Original poster: "Mike" <induction@xxxxxxxxxxx>
> Hi Finn,
> I saw this earlier but waited to confirm the "in person" and
> not on film observations of color.
> Based on streamers being to the air and arcs being to ground or another
> hard near ground target, your
> colors are confirmed. Tonight I asked Robert Golka, very pointedly in the