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"Flash synchronizer"

 
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Doug Kerr



Joined: 10 Jul 2006
Posts: 177
Location: Dallas, Texas, USA

PostPosted: Wed Aug 02, 2006 1:46 pm    Post subject: Reply with quote

As I have begun poking around in the world of press cameras and their cousins (curse you, Will Thnompson!), I keep running into the term "flash synchronizer".

It seems most commonly to refer to what the civilans would call a "flash gun" (or sometimes "flash holder"), although sometimes I see the term applied to the flash sync capability of a synchro shutter or an add-on flash sync contact for an otherwise bereft focal plane shutter.

"Flash synchronizer" seems to be a strange name to give a flash unit. Does anyone have any insight into how that came about?

Seomtimes it seems to imply that when using a flash unit the flash is synchronized with the shutter (either by virtue of using a solenoid or a synchro shutter), this being contrasted contasted with "open flash", which I assume means firing the flash while the shutter is held open in "B" or "T" (there being no electrical coordination between the flash unit and the shutter, in either direction), but of course you don't do that with the flash lamp in your hand.

So I guess what "flash synchronizer" means is "synchronizable flash unit".

Thanks for any insight you can give me.

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Best regards,

Doug
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ImageMaker



Joined: 20 Jun 2006
Posts: 93
Location: North Carolina

PostPosted: Wed Aug 02, 2006 5:10 pm    Post subject: Reply with quote

A flash synchronizer is a solenoid, operated by the current pulse that fires the flashbulb (triggered by a push-button switch mounted on the flash handle, usually), which in turn mechanically operates the shutter release for a front shutter. Correctly adjusted, it includes the proper 20 ms delay to allow for ignition of M type bulbs (can be adjusted for MF and S bulbs, also, I'd think). Instead of a synchronized shutter, in which firing the shutter closes a contact that fires the flash and the shutter must include the delay between contact closing and shutter opening, the synchronizer has the flash firing the shutter and doesn't require either synch contacts or an M delay built into the shutter.

Synchronizers were popular in the early days, when most shutters had no synch, and remained popular for as long as press cameras were front line units because they worked so well -- among other things, if you had a bad bulb that failed to fire or had forgotten to change the bulb, there'd be no current pulse, so the shutter also wouldn't fire, thereby not wasting a film. Used with an X synch shutter, it was even possible to combine bulb and xenon flash in the same exposure (though I can't think of a situation where it would be advantageous to do so).

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Doug Kerr



Joined: 10 Jul 2006
Posts: 177
Location: Dallas, Texas, USA

PostPosted: Wed Aug 02, 2006 11:44 pm    Post subject: Reply with quote

Greetings,

Quote:

On 2006-08-02 10:10, ImageMaker wrote:
A flash synchronizer is a solenoid, operated by the current pulse that fires the flashbulb (triggered by a push-button switch mounted on the flash handle, usually), which in turn mechanically operates the shutter release for a front shutter. Correctly adjusted, it includes the proper 20 ms delay to allow for ignition of M type bulbs (can be adjusted for MF and S bulbs, also, I'd think). Instead of a synchronized shutter, in which firing the shutter closes a contact that fires the flash and the shutter must include the delay between contact closing and shutter opening, the synchronizer has the flash firing the shutter and doesn't require either synch contacts or an M delay built into the shutter.


That of course all makes sense.

Why then, do we often see references to (for example), "The flash synchronizer handle is equipped with two clamps that hook onto to slots on the bracket alongside the rangefinder?" Is that just people who are confused?

For example, this is said to be from the US Army field manual covering the PH-324 camera (Kodak 35 mm)(maybe TM-11-400-A):

"c. Flash Synchronizer (fig. 11). (1) The flash synchronizer consists of a plastic case which holds two size C dry cell batteries and a reflector. Positive elec- trical contact to the flash bulb is assured by the special coni- point bulb spring. The unit is provided with a test lamp and bulb ejector. It is used with midget bayonet-base type photoflash lamps, and it requires a slight adjustment (par. 12) when used the first time with Camera PH-324-A. (2) The flash synchronizer is mounted on the camera tripod socket by means of an extension bracket. Connection to the camera lens and shutter assembly is made by screw- ing the synchronizer unit into the cable release socket. Two flashlight batteries are required to operate the synchronizer. Six batteries are supplied with the set."

However, in the illustration of the entire Flash Synchronizer, the term "Synchronizer head" is applied to what seems to be a sync "switch" that screws into the shutter. I guess it was able to confer its family name on the whole thing it drove! ("WJZ, your 50,000 watt microphone".)


Thanks for your input.

Best regards,

Doug

[ This Message was edited by: Doug Kerr on 2006-08-02 16:55 ]

[ This Message was edited by: Doug Kerr on 2006-08-02 17:03 ]

[ This Message was edited by: Doug Kerr on 2006-08-02 17:04 ]
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sobahguy



Joined: 09 Oct 2001
Posts: 171
Location: Massachusetts

PostPosted: Thu Aug 03, 2006 12:52 am    Post subject: Reply with quote

It is possible that references to "flash synchronizer" could also mean the earlier (and now more expensive) chrome "movie prop" battery case, which came out circa 1938 and was replaced about 10 years later by the Graflite model. The instruction manual that I have for the older "saber" hilt model calls this flash a "synchronizer" right on the front cover.
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Doug Kerr



Joined: 10 Jul 2006
Posts: 177
Location: Dallas, Texas, USA

PostPosted: Thu Aug 03, 2006 2:09 am    Post subject: Reply with quote

Quote:

On 2006-08-02 17:52, sobahguy wrote:
The instruction manual that I have for the older "saber" hilt model calls this flash a "synchronizer" right on the front cover.


Very interesting. That is the Graflex (not Graflite) flash rig.

Thanks.

Best regards,

Doug
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alecj



Joined: 09 May 2001
Posts: 853
Location: Alabama

PostPosted: Thu Aug 03, 2006 6:59 am    Post subject: Reply with quote

Doug, you are correct. The terms are used in strange ways. Sometimes the reference was to the gun, sometimes to the solenoid.

It gets worse because other companies, e.g. Kalert also made flash guns, and some of them made devices OTHER THAN solenoids to synchronize those flash guns with lenses w/o internal sync. Kalert's for instance looks like a cable release with a box at the back end containing a plug for a flash cord. It was adjustable to sync w/different flash bulbs.

Just accept the fact some strange decisions were made in those old days. You are not alone in observing this non-standard word useage.
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Doug Kerr



Joined: 10 Jul 2006
Posts: 177
Location: Dallas, Texas, USA

PostPosted: Thu Aug 03, 2006 3:55 pm    Post subject: Reply with quote

Quote:

On 2006-08-02 23:59, alecj wrote:
Just accept the fact some strange decisions were made in those old days. You are not alone in observing this non-standard word useage.


Yes, indeed. I'm certainly used to that. I just wanted to be sure I wasn't missing something!

Thanks.

Best regards,

Doug
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45PSS



Joined: 28 Sep 2001
Posts: 3230
Location: Mid Peninsula, Ca.

PostPosted: Fri Aug 04, 2006 12:40 am    Post subject: Reply with quote

Come on guys, clean off the cob webs.

You've been using cameras for years, have gotten quite good at putting the right amount of powder on its holder, removing the lens cap and igniting the flash powder and putting the lens cap back on and getting great results. To that I say congrats!

NOW someone (a company) comes along and presents a gadget with a bulb and a way to get it to go off when the shutter is wide open so what do you or the company call it?
Flash Synchronizer of course.

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Les



Joined: 09 May 2001
Posts: 2682
Location: Detroit, MI

PostPosted: Sun Aug 06, 2006 3:45 pm    Post subject: Reply with quote

Quote:

On 2006-08-02 10:10, ImageMaker wrote:
if you had a bad bulb that failed to fire or had forgotten to change the bulb, there'd be no current pulse, so the shutter also wouldn't fire, thereby not wasting a film.


This isn't true, at least not with Graflex, Graflite, Heiland, Mendelson or Kalart flash units, there may be others that this is true for, but I doubt it.

There are two circuits, one circuit for the solenoid, one for the flash. Both of these circuits are closed at the same time when the red button on the back of the battery case is pushed. If there's a bad bulb, or no bulb, the current to the solenoid isn't interrupted, it will still fire. Now if you're in a dark room and had the aperture set to f8 or greater, then the film didn't get exposed to enough light to have an effect and could be used again.

Graflex, in their 1945 catalog called it a "Graflex Flash Synchronizer complete: consisiting of a battery case with batteries, camera bracket, indicated reflector, solenoid and connecting cord."

without the solenoid, it became a "Graflex Flashing Unit"

Other companies used the terms differently, but most often it was all the equipment necessary to synchronize the flash bulb with the shutter.
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ImageMaker



Joined: 20 Jun 2006
Posts: 93
Location: North Carolina

PostPosted: Sun Aug 06, 2006 10:54 pm    Post subject: Reply with quote

Quote:

On 2006-08-06 08:45, Les wrote:
Quote:

On 2006-08-02 10:10, ImageMaker wrote:
if you had a bad bulb that failed to fire or had forgotten to change the bulb, there'd be no current pulse, so the shutter also wouldn't fire, thereby not wasting a film.


This isn't true, at least not with Graflex, Graflite, Heiland, Mendelson or Kalart flash units, there may be others that this is true for, but I doubt it.


Ack.

Guess it's a good thing I don't have one. One must presume this is the case because either a) the bulb won't pass enough current to draw in the solenoid, or b) the bulb's igniter burns through too quickly for the solenoid to pull in; otherwise, there'd be no reason to use a double-pole switch when a single-pole would do the same job (more cheaply and reliably).

OTOH, this behavior would provide a convenient body release for the Anniversary Speed, which didn't have one for the front shutter (given front shutters became standard on these well into the model run).

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Doug Kerr



Joined: 10 Jul 2006
Posts: 177
Location: Dallas, Texas, USA

PostPosted: Sun Aug 20, 2006 1:56 am    Post subject: Reply with quote

Here is part of the story:

For the "Graflex" flash units:

The term "Flash Synchronizer" is used to refer to the "flash gun" plus the solenoid that came with it to be mounted on the lens shutter (for a non-sync shutter, or of course if you just wanted to trip the shutter from the red button on the flash).

The term "Flashing Unit" is used to mean the "flash gun", period.

Best regards,

Doug
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