yachica 124G sync question

Discussion in 'Medium Format' started by alec_holst, Sep 4, 2004.

  1. i just got my yashica 124G and am very pleased with it so far. a
    couple questions though, i'm going to be using a vivitar 285HV with
    this camera and don't know if i should set the yashica to M or X. i
    read soemwhere that M is for old flashes it is causes the flash to
    fire a little before the shutter, is this correct? Also, i have
    never used a TRL before and wonder if what you see in the focusing
    screen is really what you get or is it an inch or so higher? thanks
    in advance
     
  2. Set the sync on X and tape it down. I think you are correct about
    M.
     
  3. Yes, X is for electronic flash. If everything were perfectly aligned, the focusing screen would always show an image that was higher up by the exact center-to-center distance of the two lenses. At 20' on real cameras, I doubt any edge is that accurate. For closeups it becomes an issue, and you can raise the camera by the c-c distance before making the exposure.
     
  4. M sync, was for flash bulbs, that had a longer peak as they burned.X sync is what you want for strobes.
     
  5. As others have said, use the X sync. As for parallax, (the difference between the position of the lenses), anything from about four feet on should be ok unless you have an important part of the image at the very top of the viewfinder frame. If this is the case, or if you want to do macro photography using 1-2-3 diopters, raise the camera a distance equal to the distance between centers of the two lenses. The viewing lens and taking lens are very close to 1.25 inches (about 32mm) apart, vertically. As an example, if you are taking a shot of a coin using diopters to achieve a focus of, say, five inches, you would position the coin in the viewfinder and focus using the diopters on the viewing lens, then transfer the diopters to the taking lens and raise the camera 1.25 inches, then take your shot. The image of the coin will then be in the same place on the film as it was in the viewfinder. You need to keep in mind that what you want to raise, in effect, is the plane of the film in a relationship to the object you are wanting to keep properly positioned on the film. So this method works best when your camera is mounted on a tripod with the camera base parallel to the ground. Years ago I used this method with one of my 'Mats when taking some extreme close-up shots of a collectors watches. Works very well.
     
  6. Keep in mind also that with leaf shutter cameras such as your Yashica you have flash sync available at every speed - unlike most focal plane shutters which top out at a certain speed (tho' they can be synced below that speed), beyond which only part of the frame is properly exposed. Very helpful when using flash with fast films or in daylight.
     
  7. yes one of the main reasons i got the 124g was because of the 1/500th sync and the price. how come it can sync at that speed but pro slrs can only sync at 1/250th? you said something about a leaf shutter? is it because there is no mirror? also is it safe to touch the focusing screen for cleaning purposes? thanks.
     
  8. Alec, the multi-leaf between the lens shutters have shutter blades which open and close similtaneously in a radial movement from the center. The flash fires once the shutter blades are open all the way. The flash duration of an electronic strobe is over and done with long before the shutter blades can close begin to close.

    SLR's use a two sets of curtains that move either horizontally or vertically to control the exposure at the focal plane. The first curtain moves across the frame at a set speed, while the second follows with varying degrees of delay, but at the same speed as the first curtain. The second curtain ends the exposure. The flash synch speed is the fastest speed in which the first curtain is fully open and second curtain has yet to even begin its motion across the film plane. It is at this point the full frame is exposed to light.

    At any speed faster than the synch speed then the motion of the second curtain has already begun its motion across the film plane before the first curtain has fully opened and is therefore already block part of the frame. The flash fires once the first curtain is fully open and you tend to get rather disatisfying results, if the second curtain is already blocking part of the frame.

    BTW, the horizontal curtains some older medium format SLR's can have a flash synch speed that is low as 1/30th of second, which truly makes it tricky to do a fill-flash in bright sunlight.

    Enjoy the TLR. Once you get past the inverted left to right image of the focusing screen, they are an absolute joy to compose with.
     
  9. On most TLRs I know the focussing screen shows a bit less than the actual image frame (the 6x6 frame actually is 56x56mm, and focussing screens are in the 53x53mm - Hasselblad - to 48x48mm - french Kinaflex) range. So even if there is a minor parallax you will see on the image just at least as much as on the screen, although the actual image might be a bit off-center.
     
  10. To make the flash issue even more needlessly complicated, Olympus has made a few SLR cameras with focal plane shutters capable of flash sync at the cameras' highest shutter speeds, 1/2000.

    It's a neat trick that sounds better in theory than it is useful in practice. For one thing, the OM-4 required a special flash unit available only from Olympus to take advantage of this feature. However high speed flash sync is built into a couple of Olympus' ZLR (zoom lens reflex) iS-series non-interchangeable zoom lens cameras.

    This kind of high speed flash is generally limited to short distances or for freezing action more effectively under bright ambient light while still having the advantage of fill flash.

    But before these puppies came along the leaf shutter was king of the high flash sync speed game.
     
  11. Even more unique is the system used on the Nikon D70 digital SLR. The shutter is mechanically limited to a fairly normal X-synch (1/125?) but the CCD sensor acts as an electronic shutter that "opens" and "closes" during the time that the mechanical shutter is fully opened. The camera officially synchs to 1/500 but people have tricked it to synch even faster. Obviously not possible with film.

    If you ever shoot with M synch with a strobe you will be sorry! When setting up for an important shoot, always take care to fire the flash while looking through the back of the film gate. You should be able to see the flash fire when the shutter opens.
     
  12. 124G flash questions answered (maybe) here:
    http://www.geocities.com/y124g/front.html
     

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