X-Synch on the Graflex RB Super D
I was puzzled that the internets seems to have no information on the Super D’s flash synch. I posted on Graflex.org looking for some insight, but ended up – eventually – investigating the system myself.
The result? Yes, you can use electronic flash on your Graflex RB Super D! How? well, simple. Using what some folk call “drop curtain”: what this meant was obscure to me too, but I worked it out. The shutter on the Super D gives you speeds from 1/30 to 1/1000, however there are two other speeds which you can obtain: if you lock your mirror down, and roll the shutter curtain to “O”, when you release the shutter, the mirror flips up exposing your film, then the shutter closes. At the lower spring tension you get approximately 1/5, and at high spring tension you can obtain 1/10. This is brilliant, isn’t it? Yes, but even more so when you consider that these two speeds can also be used with electronic flash, as the flash contacts close when the mirror completely clears the film gate!
Once I had figured all of this out, I was disappointed to find that I was unable to trigger my flash, so I had to check the flash contacts and see what was up. To get at the mechanism, you need to remove the shutter plate (where you set the curtain aperture and flip the mirror). Before taking off the plate, I would suggest removing the back (remember there are a few hidden screws that you can only access with the back partly rotated), so that you can use a (white) pencil to mark the position of the upper lip of the shutter curtain on “O”. To remove the shutter plate only four screws need to be removed, but you also need to extract the pin that is on the mirror shaft. This took me a couple of weeks, and I ended up using a microjet torch (the variety that takes a butane lighter inside, and burns up to 1300c with a tiny sharp flame) to heat up the metal locally, just enough to be able to tap the pin out. The concentrated heat seems to not cause any problems, and with a few seconds was just enough to loosen its grip. Be careful and gentle – don’t force anything. Then remove the four screws (one may be flat-headed), and the shutter will close. Don’t panic.
What you will find is that the actual mechanism of the Super D’s shutter is remarkably compact and simple, and that the flash contacts themselves are little platinum tips like what one would expect inside a motorbike engine’s distributor. Give everything a wee clean. The leather will probably have a bit of greenish waxy oxide on it, and some dust. The flash contacts are very easy to adjust, but I would start by spraying some contact-cleaner or switch-cleaner into them, and maybe fiddling a bit of paper over the platinum points. The reason why my flash was not triggering is that the “thumb” at the bottom-right of the shutter mechanism. The thumb is the spring-loaded part which is meant to close the contacts when the mirror hits home. Said this, it also appears to be held in place with a tin-plated screw which has oxidised over the past 65 years, and hence become a bit stiff. So unscrew that, use a dry brush to clear off the oxide, then I added some PTFE lubricant and reassembled the thumb. Check that all of the other moving parts are free. I added some PTFE to a couple of the other pivots, and cleaned the dry grease from the upper curtain roller bush. Make sure you did not get any lubricant on the flash contacts (or clean them again), and check that the gap is good: connect an ohmmeter to the contact prongs, and rotate the mechanism to make sure that the thumb is closing the circuit, and that it is opening again. If you need to adjust it, you bend the upper contact by a hair, using a screwdriver or something (it is very malleable). It is also worthy of note that the flash timing would be adjusted by the shape of the thumb, but it should be right, so don’t bend it.
Once you are satisfied that everything should work smoothly, rotate the curtain key until the “O” is centred in its window again, as you are likely to have wound the gears way past its correct positioning. Make sure it is centred, and not just visible. At the back of the camera, wind the curtain up until your pencil marks match. Try using something like masking tape on the ribbons to hold it, probably just above its marked position, so that you have enough play to mesh the gears. Place the shutter plate onto the two pivots, and wiggle it until your gears mesh, place two screws to hold it tight, then untape your curtain, and check that it holds with your pencil marks matched up. If they do, then try running the shutter at its different gaps to make sure they are all correct (as in they start with the gate closed, and end with the gate closed). Replace the other two screws, position the mirror lever and replace its pin (which may not be easy). Replace the rotating back.
If you are lucky, you may have some kind of a cable which plugs into the two-pronged flash port. I did not. So I had to make an adapter. I made the contacts out of a figure-8 connector, which i covered in heat-shrink tubing, soldered on a PC socket, and then caked the lot in Milliput® epoxy putty. I put cling-film in the socket first, so that I could get my putty out when it had cured (this works well), and then I filed and sanded it back. Some day I shall get round to painting it black too.
In conclusion, this solution makes the Super D one of the most ductile large-format portrait cameras, as you can look through the lens without the delay of then closing down the shutter to load film. Though the Super D has automatic diaphragming for its own three lenses, I only have one of these, and plan to modify the front standard to take brighter lenses like the Dallmeyer Pentac 8″ f2.9, and being able to use electronic flash with these lenses is quite an unusual privilege.