Your flash can damage your camera!

On Tue, 19 Oct 2004 11:15:49 -0500, "me" wrote:

"Michael A. Covington" wrote in message
...
"me" wrote in message
...
When I found out that some flash units use very high trigger voltages,
several hundred volts in some cases, I was very displeased.

That's how electronic flash tubes work. Remember, good high-voltage
thyristors (for low-voltage electronic switching) did not exist when
electronic flash was first invented.

At that time they were using metal contacts. Metal contacts can withstand
almost any amount of voltage provided that the arcing that occurs when the
contacts open and close isn't so severe that it causes excessive pitting.
What I failed to say in my original post is that it isn't necessary to use
such high voltages to trigger the flash. A simple relay could act as a
switch to control the high voltage that powers the flash tube and thus
protect the camera's flash circuitry from any risk of damage.
I can understand why flash units made in the time when cameras used metal
contacts in their flash switch didn't do this, there wasn't any need. But
there is a definitely a need now.
What annoys me is that modern cameras manufacturers are unable (too cheap)
to add a simple relay to handle those flashes that still route the high
voltage through the camera to power the flash tube.
I don't blame flash manufacturers for what they did 20+ years ago. At that
time it made sense to do it that way. Why some of them are still using the
high voltage to switch the flash makes no sense at all.
Camera manufacturers have no excuse. They are aware of the problem and they
do nothing about it. This is unacceptable. All they have to do is add a
relay and the problem would be solved.

'Simple relays' cannot respond in 1/10000th sec. Think "speed of
light" not "speed of mechanical switches". Some form of electronic
gate circuitry would be more appropriate.

I also think your argument to have today's cameras be specifically
modified to include support for archaic hardware is rather absurd
given the tremendous advances in Multi-channel Wireless/TTL/iTTL/3D
Matrix metering/HSS available in tandem with modern flash units. If
you are in the 2% of photographers that need high-voltage support,
then buy a piece of hardware that can do the interface safely.

--
Owamanga!

"Owamanga" wrote in message
...
On Tue, 19 Oct 2004 11:15:49 -0500, "me" wrote:

"Michael A. Covington" wrote in message
...
"me" wrote in message
...
When I found out that some flash units use very high trigger
voltages,
several hundred volts in some cases, I was very displeased.

That's how electronic flash tubes work. Remember, good high-voltage
thyristors (for low-voltage electronic switching) did not exist when
electronic flash was first invented.

At that time they were using metal contacts. Metal contacts can
withstand
almost any amount of voltage provided that the arcing that occurs when
the
contacts open and close isn't so severe that it causes excessive pitting.
What I failed to say in my original post is that it isn't necessary to
use
such high voltages to trigger the flash. A simple relay could act as a
switch to control the high voltage that powers the flash tube and thus
protect the camera's flash circuitry from any risk of damage.
I can understand why flash units made in the time when cameras used metal
contacts in their flash switch didn't do this, there wasn't any need.
But
there is a definitely a need now.
What annoys me is that modern cameras manufacturers are unable (too
cheap)
to add a simple relay to handle those flashes that still route the high
voltage through the camera to power the flash tube.
I don't blame flash manufacturers for what they did 20+ years ago. At
that
time it made sense to do it that way. Why some of them are still using
the
high voltage to switch the flash makes no sense at all.
Camera manufacturers have no excuse. They are aware of the problem and
they
do nothing about it. This is unacceptable. All they have to do is add a
relay and the problem would be solved.

'Simple relays' cannot respond in 1/10000th sec. Think "speed of
light" not "speed of mechanical switches". Some form of electronic
gate circuitry would be more appropriate.

I was referring to the mechanical switches in cameras 20+ years ago. Think
"focal plane shutter". Even focal plane shutters of today typically have a
flash sync speed 1/60 of a second (some are slightly faster). Your
assumption that the flash trigger circuitry in a camera has to turn the
flash on in 1/10000 is incorrect. I am not aware of any camera with a focal
plane shutter that has a flash sync speed of 1/10000 of a second.

I also think your argument to have today's cameras be specifically
modified to include support for archaic hardware is rather absurd
given the tremendous advances in Multi-channel Wireless/TTL/iTTL/3D
Matrix metering/HSS available in tandem with modern flash units. If
you are in the 2% of photographers that need high-voltage support,
then buy a piece of hardware that can do the interface safely.

--
Owamanga!

"Owamanga" wrote in message
...
On Tue, 19 Oct 2004 11:15:49 -0500, "me" wrote:

"Michael A. Covington" wrote in message
...
"me" wrote in message
...
When I found out that some flash units use very high trigger
voltages,
several hundred volts in some cases, I was very displeased.

That's how electronic flash tubes work. Remember, good high-voltage
thyristors (for low-voltage electronic switching) did not exist when
electronic flash was first invented.

At that time they were using metal contacts. Metal contacts can
withstand
almost any amount of voltage provided that the arcing that occurs when
the
contacts open and close isn't so severe that it causes excessive pitting.
What I failed to say in my original post is that it isn't necessary to
use
such high voltages to trigger the flash. A simple relay could act as a
switch to control the high voltage that powers the flash tube and thus
protect the camera's flash circuitry from any risk of damage.
I can understand why flash units made in the time when cameras used metal
contacts in their flash switch didn't do this, there wasn't any need.
But
there is a definitely a need now.
What annoys me is that modern cameras manufacturers are unable (too
cheap)
to add a simple relay to handle those flashes that still route the high
voltage through the camera to power the flash tube.
I don't blame flash manufacturers for what they did 20+ years ago. At
that
time it made sense to do it that way. Why some of them are still using
the
high voltage to switch the flash makes no sense at all.
Camera manufacturers have no excuse. They are aware of the problem and
they
do nothing about it. This is unacceptable. All they have to do is add a
relay and the problem would be solved.

'Simple relays' cannot respond in 1/10000th sec. Think "speed of
light" not "speed of mechanical switches". Some form of electronic
gate circuitry would be more appropriate.

I was referring to the mechanical switches in cameras 20+ years ago. Think
"focal plane shutter". Even focal plane shutters of today typically have a
flash sync speed 1/60 of a second (some are slightly faster). Your
assumption that the flash trigger circuitry in a camera has to turn the
flash on in 1/10000 is incorrect. I am not aware of any camera with a focal
plane shutter that has a flash sync speed of 1/10000 of a second.

I also think your argument to have today's cameras be specifically
modified to include support for archaic hardware is rather absurd
given the tremendous advances in Multi-channel Wireless/TTL/iTTL/3D
Matrix metering/HSS available in tandem with modern flash units. If
you are in the 2% of photographers that need high-voltage support,
then buy a piece of hardware that can do the interface safely.

--
Owamanga!

"Owamanga" wrote in message
...
On Tue, 19 Oct 2004 11:15:49 -0500, "me" wrote:

"Michael A. Covington" wrote in message
...
"me" wrote in message
...
When I found out that some flash units use very high trigger
voltages,
several hundred volts in some cases, I was very displeased.

That's how electronic flash tubes work. Remember, good high-voltage
thyristors (for low-voltage electronic switching) did not exist when
electronic flash was first invented.

At that time they were using metal contacts. Metal contacts can
withstand
almost any amount of voltage provided that the arcing that occurs when
the
contacts open and close isn't so severe that it causes excessive pitting.
What I failed to say in my original post is that it isn't necessary to
use
such high voltages to trigger the flash. A simple relay could act as a
switch to control the high voltage that powers the flash tube and thus
protect the camera's flash circuitry from any risk of damage.
I can understand why flash units made in the time when cameras used metal
contacts in their flash switch didn't do this, there wasn't any need.
But
there is a definitely a need now.
What annoys me is that modern cameras manufacturers are unable (too
cheap)
to add a simple relay to handle those flashes that still route the high
voltage through the camera to power the flash tube.
I don't blame flash manufacturers for what they did 20+ years ago. At
that
time it made sense to do it that way. Why some of them are still using
the
high voltage to switch the flash makes no sense at all.
Camera manufacturers have no excuse. They are aware of the problem and
they
do nothing about it. This is unacceptable. All they have to do is add a
relay and the problem would be solved.

'Simple relays' cannot respond in 1/10000th sec. Think "speed of
light" not "speed of mechanical switches". Some form of electronic
gate circuitry would be more appropriate.

I was referring to the mechanical switches in cameras 20+ years ago. Think
"focal plane shutter". Even focal plane shutters of today typically have a
flash sync speed 1/60 of a second (some are slightly faster). Your
assumption that the flash trigger circuitry in a camera has to turn the
flash on in 1/10000 is incorrect. I am not aware of any camera with a focal
plane shutter that has a flash sync speed of 1/10000 of a second.

I also think your argument to have today's cameras be specifically
modified to include support for archaic hardware is rather absurd
given the tremendous advances in Multi-channel Wireless/TTL/iTTL/3D
Matrix metering/HSS available in tandem with modern flash units. If
you are in the 2% of photographers that need high-voltage support,
then buy a piece of hardware that can do the interface safely.

--
Owamanga!

Owamanga wrote:

'Simple relays' cannot respond in 1/10000th sec. Think "speed of
light" not "speed of mechanical switches". Some form of electronic
gate circuitry would be more appropriate.

It is childs play for an engineer to make a circuit that will close a wide range
of voltages in differing polarities. That some camera makers skimped on this is
testimony to their beligerent attitude wrt customers investment in equipment.


I also think your argument to have today's cameras be specifically
modified to include support for archaic hardware is rather absurd
given the tremendous advances in Multi-channel Wireless/TTL/iTTL/3D
Matrix metering/HSS available in tandem with modern flash units. If
you are in the 2% of photographers that need high-voltage support,
then buy a piece of hardware that can do the interface safely.

Wein Safe Sync.


--
-- rec.photo.equipment.35mm user resource:
-- http://www.aliasimages.com/rpe35mmur.htm
-- e-meil: there's no such thing as a FreeLunch.--

Owamanga wrote:

'Simple relays' cannot respond in 1/10000th sec. Think "speed of
light" not "speed of mechanical switches". Some form of electronic
gate circuitry would be more appropriate.

It is childs play for an engineer to make a circuit that will close a wide range
of voltages in differing polarities. That some camera makers skimped on this is
testimony to their beligerent attitude wrt customers investment in equipment.


I also think your argument to have today's cameras be specifically
modified to include support for archaic hardware is rather absurd
given the tremendous advances in Multi-channel Wireless/TTL/iTTL/3D
Matrix metering/HSS available in tandem with modern flash units. If
you are in the 2% of photographers that need high-voltage support,
then buy a piece of hardware that can do the interface safely.

Wein Safe Sync.


--
-- rec.photo.equipment.35mm user resource:
-- http://www.aliasimages.com/rpe35mmur.htm
-- e-meil: there's no such thing as a FreeLunch.--

Owamanga wrote:

'Simple relays' cannot respond in 1/10000th sec. Think "speed of
light" not "speed of mechanical switches". Some form of electronic
gate circuitry would be more appropriate.

It is childs play for an engineer to make a circuit that will close a wide range
of voltages in differing polarities. That some camera makers skimped on this is
testimony to their beligerent attitude wrt customers investment in equipment.


I also think your argument to have today's cameras be specifically
modified to include support for archaic hardware is rather absurd
given the tremendous advances in Multi-channel Wireless/TTL/iTTL/3D
Matrix metering/HSS available in tandem with modern flash units. If
you are in the 2% of photographers that need high-voltage support,
then buy a piece of hardware that can do the interface safely.

Wein Safe Sync.


--
-- rec.photo.equipment.35mm user resource:
-- http://www.aliasimages.com/rpe35mmur.htm
-- e-meil: there's no such thing as a FreeLunch.--

wrote:
The site says the Vivitar 2000 is unsafe to use on EOS cameras but I use
mine on my Rebel 2000 and my other Rebel without any problems. The
report shows different results from different reporters. I think they
made the newer one different from the older ones and did not change the
model number. I think I could use this flash on any camera that has a
hotshoe.

Newer Canon cameras will work just fine with any trigger voltage...until
the shutter contact gets burnt out (a cumulative problem). Good luck.

-Dave

wrote:
The site says the Vivitar 2000 is unsafe to use on EOS cameras but I use
mine on my Rebel 2000 and my other Rebel without any problems. The
report shows different results from different reporters. I think they
made the newer one different from the older ones and did not change the
model number. I think I could use this flash on any camera that has a
hotshoe.

Newer Canon cameras will work just fine with any trigger voltage...until
the shutter contact gets burnt out (a cumulative problem). Good luck.

-Dave

"Owamanga" wrote in message
...
On Tue, 19 Oct 2004 11:15:49 -0500, "me" wrote:

"Michael A. Covington" wrote in message
...
"me" wrote in message
...

[SNIP]
Camera manufacturers have no excuse. They are aware of the
problem and they do nothing about it. This is unacceptable. All they
have to do is add a relay and the problem would be solved.

'Simple relays' cannot respond in 1/10000th sec. Think "speed of
light" not "speed of mechanical switches". Some form of electronic
gate circuitry would be more appropriate.

Sure, not a mechanical relay - but it's hardly rocket science. Think Wein
safe sync. and you see how small and low cost the circuit is. (And you
don't need anything like 1/10,000.)

I also think your argument to have today's cameras be specifically
modified to include support for archaic hardware is rather absurd
given the tremendous advances in Multi-channel Wireless/TTL/iTTL/3D
Matrix metering/HSS available in tandem with modern flash units. If
you are in the 2% of photographers that need high-voltage support,
then buy a piece of hardware that can do the interface safely.

Archaic? A very large amount of studio flash exceeds 6v. Ditto a lot of
Metz units that are extremely capable. If you want multi-channel wireless
thinks-for-you and makes-the-coffee-too flash then you always had to go with
the OEM stuff anyway, but there's a huge amount of stuff, both studio and
comparatively recent SCA guns, that are in regular and worthwhile use around
the world, and sync. at more than 6v. (My studio flash is all 12v sync., as
it happens.)


Peter