Flash sync for older cameras

Discussion in 'Camera Building, Repairs & Modification' started by Sethasaurus, Apr 4, 2011.

  1. Sethasaurus

    Sethasaurus Member

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    Hello all. I've got a nice old flashgun on the way which I'm going to transplant an electronic flash into (it's all about the looks!).
    I'm wondering if anyone has a solution similar to this flash sync cable

    This is made for the Kalart flashes but the flash I am buying is more of a 'no name' one and I don't think it has the same connector (2 pins on the back of the sync cable).

    Just wondering if anyone else had come up with an alternative mechanical or electronic solution which allows some adjustment for syncing the flash to the shutter.

    My other option is to opt for a high power LED and batteries, instead of the xenon tube and circuit, and just use a thumb-operated pushbutton while I trip the shutter with a standard shutter cable.
     
  2. Matthew Rusbarsky

    Matthew Rusbarsky Member

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    Thinking about doing something like this? If the camera has an X sync, you are in business. If not, you are going to have to figure out a way to slow down the sync so your flash does not fire before the shutter is fully open.
     
  3. Sethasaurus

    Sethasaurus Member

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    I forgot to add - most of the cameras I want to use it with are pre-ww2 and have no shutter sync.
    Those with Compur shuters, for example can be synced with a cable like in the URL. It's adjustable by screwing the collar on the cable in/out to get the contacts to close in sync with the pin on the end of the cable release.
     
  4. greybeard

    greybeard Member

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    My other option is to opt for a high power LED and batteries, instead of the xenon tube and circuit, and just use a thumb-operated pushbutton while I trip the shutter with a standard shutter cable.

    Wow, what a cool idea--I had thought about gutting an electronic flash and transplanting the works into a Graflex flash for a Speed Graphic, but it occurs to me that a few big storage capacitors and a group of high-power LED modules would probably be good enough for flash pictures indoors or good fill light outdoors (like the old Polaroid Wink-Lights).

    If you go with the Graflex-style release (a pushbutton on the flash energizes a solenoid at the lensboard which trips the shutter) you could probably use a pair of IC timers to sequence the shutter and flash, to fire when the shutter is fully open. The slower you can run the shutter (not so hard in the days of 25-speed film, maybe trickier now) the easier this will be.
     
  5. Sethasaurus

    Sethasaurus Member

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    greybeard,
    With the kinds of Lithium batteries and hi-output LEDs available now, it doesn't have to be complex.

    Basically, I would hold the LED button on to illuminate the area/subject and hit the shutter when I'm ready. No real need for a sync as you might hold the 'light' button on for several seconds. (Call it 'professonal photgraphic lighting' in the body of an old fasioned flash? :wink:

    Some of the LEDs I'm looking at on ebay quote an output of 1000 lumen at a forward current of 3000mA @ 3.35V, which I suspect is going to be quite bright enough for a portrait or group shot.
    I'm mentally comparing these high-output LEDs (10W) with the tiny (possibly <1W) flash LED on my blackberry, which isn't too bad but could be brighter.

    Match them up with say, a rechargeable CR123A 2000mAh Li-ion battery (or 2 in parallel will fit in the handle) and you've got around 2400 shots if you hit the button for a second each time (for about 12 of those US dollars).

    One thing you need with the LED is a small aluminium heatsink or it'll burn out with prolonged use. The LED & heatsink could be mounted in a standard lamp base and fitted in the socket.

    I've just noticed some other 4-colour LEDS (RGB+white) which you could use to mix colours, given a bit of extra circuitry..

    OK nobody try this cos it probably won't work anyway.
    ** runs off to buy up all the vintage flashes **

    I think I'll try the LED first, but I did find that the guts of a Sunpak Auto33 flash + batteries will easily fit inside the handle.
     
  6. Sethasaurus

    Sethasaurus Member

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    Illuminance - Recommended Light Levels

    Just thought I'd reproduce this here as useful information. I took it from engineeringtoolbox.com

    Recommended light levels - illuminance - for some common types of working activities
    Light Level or Illuminance, is the total luminous flux incident on a surface, per unit area. The work plane is where the most important tasks in the room or space are performed.

    Measuring Units Light Level - Illuminance
    Illumenance is measured in foot candles (ftcd, fc, fcd) (or lux in the metric SI system). A foot candle is actually one lumen of light density per square foot, one lux is one lumen per square meter.

    • 1 lux = 1 lumen / sq meter = 0.0001 phot = 0.0929 foot candle (ftcd, fcd)
    • 1 phot = 1 lumen / sq centimeter = 10000 lumens / sq meter = 10000 lux
    • 1 foot candle (ftcd, fcd) = 1 lumen / sq ft = 10.752 lux

    Common Light Levels Outdoor
    Common light levels outdoor at day and night can be found in the table below:
    Condition - Illumination (ftcd) (lux)
    Sunlight 10,000 107,527
    Full Daylight 1,000 10,752
    Overcast Day 100 1,075
    Very Dark Day 10 107
    Twilight 1 10.8
    Deep Twilight .1 1.08
    Full Moon .01 .108
    Quarter Moon .001 .0108
    Starlight .0001 .0011
    Overcast Night .00001 .0001


    Common and Recommended Light Levels Indoor

    The outdoor light level is approximately 10,000 lux on a clear day. In the building, in the area closest to windows, the light level may be reduced to approximately 1,000 lux. In the middle area its may be as low as 25 - 50 lux. Additional lighting equipment is often necessary to compensate the low levels.
    Earlier it was common with light levels in the range 100 - 300 lux for normal activities. Today the light level is more common in the range 500 - 1000 lux - depending on activity. For precision and detailed works, the light level may even approach 1500 - 2000 lux.

    The table below is a guidance for recommended light level in different work spaces:
    Activity - Illumination (lux, lumen/m2)
    Public areas with dark surroundings 20 - 50
    Simple orientation for short visits 50 - 100
    Working areas where visual tasks are only occasionally performed 100 - 150
    Warehouses, Homes, Theaters, Archives 150
    Easy Office Work, Classes 250
    Normal Office Work, PC Work, Study Library, Groceries, Show Rooms, Laboratories 500
    Supermarkets, Mechanical Workshops, Office Landscapes 750
    Normal Drawing Work, Detailed Mechanical Workshops, Operation Theatres 1,000
    Detailed Drawing Work, Very Detailed Mechanical Works 1500 - 2000
    Performance of visual tasks of low contrast and very small size for prolonged periods of time 2000 - 5000
    Performance of very prolonged and exacting visual tasks 5000 - 10000
    Performance of very special visual tasks of extremely low contrast and small size 10000 - 20000

    "The content in The Engineering ToolBox is copyrighted but can be used with NO WARRANTY or LIABILITY. Important information should always be double checked with alternative sources. All applicable national and local regulations and practices concerning this aspects must be strictly followed and adhered to."
     
  7. 2F/2F

    2F/2F Member

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    If it is all about the looks, there are a few choices for bare-bulb electronic flashes in circular "bowl" reflectors similar to the right angled Graflex or Heiland ones. The lighting they provide is extremely similar to these old flashguns. The Sunpak 622 has an optional bare bulb head, and Quantum has one as well.