Cult of Sharpness

On Fri, 13 Nov 2009 10:48:09 +1300, Eric Stevens
wrote:

On Thu, 12 Nov 2009 22:03:07 +1000, Bob Larter
wrote:

Eric Stevens wrote:
On Thu, 12 Nov 2009 17:25:44 +1000, Bob Larter
wrote:

Eric Stevens wrote:
On Wed, 11 Nov 2009 21:03:44 +1000, Bob Larter
wrote:

Eric Stevens wrote:
On Wed, 11 Nov 2009 15:03:10 +1000, Bob Larter
wrote:

Bob Larter is Lionel Lauer - Look it up. wrote:
On Wed, 11 Nov 2009 14:45:16 +1000, Bob Larter
wrote:

Uh - you forgot something important - again wrote:
It is due to the high physical compression of the dielectric layers in the
capacitor being suddenly released. Producing a pulse of motion expanding
from the discharging capacitor.
What a complete load of bull****. For starters; I've spent a total of
about 20 years in the electronics industry (both design & service), &
I've never heard of any such effect, & I'm very familiar with weird
quirks in capacitors - particularly high voltage electrolytics, which
are the kind used in flashguns.
Secondly: if such an effect existed, it'd affect only the diameter of
the can - it wouldn't be directional, thus it wouldn't move the flashgun
in any direction.
Thirdly: If such an effect existed, it'd eventually tear the capacitor
out of the PCB or snap the leads off the cap - that doesn't happen.

PS: Nice try at screwing up the followups to prevent anyone from
debunking your bull****. ;^)
Fourthly: this only proves that you've never held a decent flash in your
hand while firing it off. Anyone who has done that can easily detect the
physical pulse of motion upon firing it.
*snort* You're imagining it, kid.
If he's imagining it, then so too am I. I've always assumed it was due
to the release of the dielectric stress in the capacitor.
Nope. Electrolytic capacitors don't do that. The 'click' is from the
expansion of the xenon gas in the flash tube. The amount of expansion is
*tiny*, but you can hear it because it happens so fast.
See http://www.madsci.org/posts/archives...9790.Eg.r.html

"A charged capacitor's plates attract each other. The dielectric
provides a reaction force keeping the plates apart. It thus feels
a mechanical compressive stress."

When the capacitor is discharged there is no longer attraction between
the plates, no reaction force is required and the dielectric is no
longer under compression. The sudden release of the compression force
enables the capacitor to expand which sudden expansion is a source of
a shock pulse.
I promise you that if electrolytic capacitors were in the habit of
changing shape as their charge varied, (suddenly or otherwise), most
electronic devices wouldn't work for very long.

Why?

Mainly because the electro's would snap off their leads from metal
fatigue, or would destroy the solder joints on the PCB. See my comments
to the P&S troll, up in the quoted part of this post.

It's possible to calculate the amplitude of the movement, and its very
small, about comparable with a tweeter speaker at the high frequency
end of its range.



Eric Stevens

You can't do that, then the red-herring DSLR-Troll Bob Larter (a.k.a.
Lionel Lauer, real home troll-group: alt.kook.lionel-lauer) would have to
use the example of how all stereo speakers and anything near them always
regularly shake themselves to death the first time you use them. This is
probably why all high-speed machinery, jets, and even cars always
self-destruct on first use due to all the vibrations imparted to their
electronics. Even all the ultrasonic motors for focusing and zooming in all
newer camera lenses destroy the lenses' electronics soldering-joints on
first use. That's a proven FACT! In a self-deluding and highly ignorant
troll's mind of course.

(Can this Bob Larter troll get any more lame with his invented excuses to
back up his ignorant and delusional claims?)

btw: the amount of pulse motion in my higher-power strobes, upon which I
employ my own design of stacked fresnel-lenses for focusing their light on
distant wildlife subjects even further (shots 200-500 ft. away and more in
total darkness) has far more motion imparted into my hand than some
tweeter's range of motion. A mid-range speaker with a nicely audible thump
imparted into it would be a closer analogy for the motion detected. Much of
the difference in our perceptions could be due to their age and newer
capacitor manufacturing technology today. If I turn down their power, then
it is slight. At lowest power almost imperceptible. At full power the pulse
of motion felt in my hand is far greater.

(original follow-up newsgroups now restored after the trolls culled them
from the list so nobody would notice them being proved wrong in the other
groups that they troll)

This thread, 'Cult of sharpness' is now closed.

Thank you to all who participated.

On Fri, 13 Nov 2009 14:48:26 +1000, Bob Larter
wrote:

Uh - you forgot something important - again wrote:
On Fri, 13 Nov 2009 10:48:09 +1300, Eric Stevens
wrote:

On Thu, 12 Nov 2009 22:03:07 +1000, Bob Larter
wrote:

Eric Stevens wrote:
On Thu, 12 Nov 2009 17:25:44 +1000, Bob Larter
wrote:

Eric Stevens wrote:
On Wed, 11 Nov 2009 21:03:44 +1000, Bob Larter
wrote:

Eric Stevens wrote:
On Wed, 11 Nov 2009 15:03:10 +1000, Bob Larter
wrote:

Bob Larter is Lionel Lauer - Look it up. wrote:
On Wed, 11 Nov 2009 14:45:16 +1000, Bob Larter
wrote:

Uh - you forgot something important - again wrote:
It is due to the high physical compression of the dielectric layers in the
capacitor being suddenly released. Producing a pulse of motion expanding
from the discharging capacitor.
What a complete load of bull****. For starters; I've spent a total of
about 20 years in the electronics industry (both design & service), &
I've never heard of any such effect, & I'm very familiar with weird
quirks in capacitors - particularly high voltage electrolytics, which
are the kind used in flashguns.
Secondly: if such an effect existed, it'd affect only the diameter of
the can - it wouldn't be directional, thus it wouldn't move the flashgun
in any direction.
Thirdly: If such an effect existed, it'd eventually tear the capacitor
out of the PCB or snap the leads off the cap - that doesn't happen.

PS: Nice try at screwing up the followups to prevent anyone from
debunking your bull****. ;^)
Fourthly: this only proves that you've never held a decent flash in your
hand while firing it off. Anyone who has done that can easily detect the
physical pulse of motion upon firing it.
*snort* You're imagining it, kid.
If he's imagining it, then so too am I. I've always assumed it was due
to the release of the dielectric stress in the capacitor.
Nope. Electrolytic capacitors don't do that. The 'click' is from the
expansion of the xenon gas in the flash tube. The amount of expansion is
*tiny*, but you can hear it because it happens so fast.
See http://www.madsci.org/posts/archives...9790.Eg.r.html

"A charged capacitor's plates attract each other. The dielectric
provides a reaction force keeping the plates apart. It thus feels
a mechanical compressive stress."

When the capacitor is discharged there is no longer attraction between
the plates, no reaction force is required and the dielectric is no
longer under compression. The sudden release of the compression force
enables the capacitor to expand which sudden expansion is a source of
a shock pulse.
I promise you that if electrolytic capacitors were in the habit of
changing shape as their charge varied, (suddenly or otherwise), most
electronic devices wouldn't work for very long.
Why?
Mainly because the electro's would snap off their leads from metal
fatigue, or would destroy the solder joints on the PCB. See my comments
to the P&S troll, up in the quoted part of this post.
It's possible to calculate the amplitude of the movement, and its very
small, about comparable with a tweeter speaker at the high frequency
end of its range.



Eric Stevens

You can't do that, then the red-herring DSLR-Troll Bob Larter (a.k.a.
Lionel Lauer, real home troll-group: alt.kook.lionel-lauer) would have to
use the example of how all stereo speakers

Which are attached on a flexible mount, & wired up with flexible copper
braid for exactly this reason.

and anything near them always
regularly shake themselves to death the first time you use them. This is
probably why all high-speed machinery, jets, and even cars always
self-destruct on first use due to all the vibrations imparted to their
electronics.

In fact, solder joints on heavy components often do fail due to
vibration. It's common practice to glue or bolt such parts to the PCB or
chassis to help prevent such failures.

Even all the ultrasonic motors for focusing and zooming in all
newer camera lenses destroy the lenses' electronics soldering-joints on
first use.

They are connected by ultra-flexible wires for this exact reason.
Flash capacitors are simply soldered direct to the PCB, just like any
other non-vibrating component.


Bob Larter's legal name: Lionel Lauer
Home news-group, an actual group in the "troll-tracker" hierarchy:
alt.kook.lionel-lauer (established on, or before, 2004)
Registered Description: "the 'owner of several troll domains' needs a group where he'll stay on topic."

http://groups.google.com/groups/search?hl=en&num=10&as_ugroup=alt.kook.lionel-lauer

"Results 1 - 10 of about 2,170 for group:alt.kook.lionel-lauer."

whisky-dave wrote:
"Wolfgang Weisselberg" wrote in message

But the NiMH batteries shrink during discharge,

Clarification: while the NiMHs are being discharged (i.e. used
to power something), not necessarily when the flash flashes.

now all the slime
has to claim is that the power comes straight out of the batteries
and the capacitor is just there for the cosmic rays or something.

I thought the capacitor was there to hold enough charge because batteries
can't
discharge the power required to make a bright enough flash.

Obviously, but the slime doesn't need to make sense, does it?

-Wolfgang