Super Graphic Electronics Question

Discussion in 'Large Format' started by henry_finley|1, May 20, 2020 at 12:42 AM.

  1. That reminds me, the Graflex company was not far from me on Monroe Avenue in Pittsford NY. After they were gone, a friend had an electronics business in the same building. There's a wonderful write-up about Rochester photo companies by Rudolf Kingslake here- A History of Rochester Camera And Lens Companies
    I have a 4x5 Crown stashed away and a really nice 2 1/4 x 3 1/4 "Mahoganite" Century Graphic with a red bellows. Only taken a couple shots with the latter. In high school, Mr. Fleetwood, the physics and photo instructor, had a 4 x 5 with the external sync, but it's been way too long to remember much about it. The Super Graphic is too upscale for me to have ever seen one.
     
  2. I've always thought that was a great article.

    When I was coming of age, mid-60s, 4x5 press cameras had pretty much gone out of style. So I think it was perhaps over the next 10 years or so that prices were reasonably low, IF YOU HAD A NEED FOR ONE. Fwiw I've had some seat time with Speed, Crown, and Super Graphics, almost always with a flash gun whether firing flash or not). In this case the Super Graphic really has no significant benefit; the flash gun is such a convenient handle and trigger for the shutter. And if you actually needed the movements a view camera is just so far superior. I'd say you didn't miss much. Except maybe the rotating back.

    Ps, I've been out of touch for so many years; I wonder if the flash guns are no longer available due to the potential use as light sabres.
     
    Last edited: May 23, 2020 at 1:20 AM
  3. Cowboy, please read post #18 above. In it I name the batteries required and point out that they can still be purchased. No need to improvise ...
     
  4. The Super Graphic has a switch on the body to fire the solenoid on the lens, rather than the mechanical shutter release of a Speed or Crown graphic. The older cameras use a switch on the flash holder to trip the solenoid. The Super Graphic did not have a focal plane shutter, rather a high speed lens shutter, as fast as 1/1000 second.

    There is no reason for a capacitor bridging the battery. If anything, there would be a non-electrolytic capacitor in parallel with the solenoid to suppress the voltage spike due to inductance, reducing arcing at the switch contacts. The batteries would only be connected when the switch was closed.
     
  5. [QUOTE="Ed_Ingold, post: 5830231, member: 419409"The Super Graphic did not have a focal plane shutter, rather a high speed lens shutter, as fast as 1/1000 second..[/QUOTE]

    Super Graphic no, Super SPEED Graphic si.
     
  6. Super Graphic no, Super SPEED Graphic si.[/QUOTE]

    Yep, I just didn't have the energy to respond. Ed also leads one to think that the Super Graphic cannot use the flash gun button to trip the shutter - it can.
     
  7. There was no focal plane shutter in the Super Speed Graphic, just the high speed lens shutter. There is a two-pronged connector on the lens which can be connected to a Graflex flash gun, which can then be used to fire the solenoid.

    That shutter was special. In order to achieve 1/1000, the blades rotated 360 degrees rather than reversing direction.
     
    lance_blakeslee likes this.
  8. The Super Graphic did not have that high speed shutter.
     
  9. Here is the circuit. The more posts I read, the more confused I get. I'm a radio man KN4SMF, and you would think I would have brains enough to understand this circuit. But I don't. For one thing, we're dealing with 45 volts worth of batteries. But look at that resistor. That would almost cause me to believe the solenoid itself is not a 45V solenoid, but something far less. Now post 24 above tells me that the solenoid has no need of capacitors to "kick "it. THAT'S what I always thought. i don't know of any solenoid I ever saw to need capacitors to fire it. The more I look at this the confuser I get. I can't even figure out which legs of A, B, and C to go the flash. In my case a Honeywell Strobonar 682S.

    SG circuit.jpg
     
  10. A is the ground. B shorted to A fires the solenoid. C is the external flash contact, referenced to A, the ground.

    The 80 mfd capacitors provide impulse power to fire the solenoid. The 2.7K resister limits the current draw to recharge the capacitors after firing. The diode supresses the reverse voltage spike due to inductance of the solenoid.
     
  11. Thank you Ed. That was very clear and now I'm happy. It was just about the way I was figuring it (for the most part). So all I really have to do is get some fresh new high quality caps in there to cut out the fear of leaky old ones bleeding down my batteries.
     
  12. Solenoids have a lot of inductance. The way to get them to fire faster is higher voltage. My guess is that's the reason for charging up the caps and using them for the high current pulse that the battery alone couldn't do. Also, applying direct battery voltage for any length of time might overheat the solenoid.
     
  13. The solenoid will have a direct battery connection as long as the switch is closed, in series with the 2.7K resistor.
     
  14. True, but it won't hurt anything other than running the battery down if for some reason the switch remained closed.
     

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