Twinning the Sony RM-VD1 Remote Commander for Digital Stereo Photography

I bought a pair of Sony cameras from B&H recently, and I also bought a pair of the matching "Remote Commanders" RM-VD1, hoping beyond hope that I could figure a way to wire the two cameras together using these plug-in remote controllers. These remotes are actually microprocessors (accounting for their $40-50 price), and use the known Sony Control-L (also called "LANC") serial protocol to communicate with the cameras through the "ACC" port found on the upper level Sony cameras. The 3/32" stereo three conductor plug povides signal at the tip, unregulated camera battery power on the middle ring, and ground at the base. Each remote has four buttons that work with a digital camera: power, shutter with 1/2 press focus lock, zoom in, and zoom out (and an unused videocamera record button). So I managed to microsolder the shutter/focus lock and power buttons between two of the remotes, and maybe another time I'll wire up the zoom buttons. The switches appear to be reasonably isolated, but I was not sure if a simple parallel wiring would work. It seems to work well with my cameras, but you will have to try it (and assume all risk of doing so) to see if this will work with yours.

Disassembly: First snap off the textured power switch cover on the outside by lifting the edge toward the rear. (thick arrow on the picture below) The front and back halves of the plastic shell snap apart; I applied firm pressure with the blade of a screw driver between the strain relief of the cable and the front shell to carefully pop it loose. The circuit board is held in place to the front shell with a single phillips screw.

Remove the screw (hidden in the picture by the wires I installed), and slightly lift the circuit board (only the side away from the power switch) off of the plastic locating pin (thin arrow). At this point, I managed to break off the power switch post and ruin one of the circuit board power switches, but you won't because you will very gently tease the power switch inside slider plate (carrot marks) off the power switch post (circle) before lifting the circuit board the rest of the way out of the front shell. I could not be certain of how the buttons were wired, so I used some de-soldering braid to take off the shutter/focus lock button on one of the remotes--you don't need to remove the button.

Solder in parallel wires: I used a knife to shave off a little of the sides of the circuit board to allow the wires to pass between the board and the shell. Three wires (A, B, C) are needed for each button, as two (A and D) of the four contacts are common (the other two solder tabs E and F secure the metal case of the button to the board and are isolated from the rest of the contacts). I think A is used as common, shutter is C, and focus lock is B. Very carefully solder tiny wires to the three solder tabs as in the pictures. I used a Weller 40 watt soldering iron, with a ST6 (0.76mm) tip, with the tip set about half way out from the setscrew element for a cooler tip. I used 0.031" rosin core solder, but I pulled the solder out quite a bit thinner prior to use. I am near sighted and did not use magnification, but I should have and you should too--these parts are very small, and a goof is harder still to fix. Be very careful not to solder to the metal case of the switch, as the case is grounded. I used a tiny bit of glue to secure the wires in position. Make sure that the wires clear the white ring around the screw hole, and clear the white circles--otherwise the wires will be pinched by the screw or shell support pins (I removed one of the shell support pins that would have pinched the power switch wires). On the back (CPU) side of the board, solder tiny wires to the two conductors of the power switch. The other two conductors of the power switch do not appear to have any function.

Reassembly: I used a microsaw to take the huge clip off the side of the back shell. I used some 1/8" shrink tubing to gather the wires into a bundle, and I used some "Goop" glue to attach the two remotes together. When installing the circuit board back in the front shell, once again, be very careful with the power switch post. I used a knife also to cut a slot between the shell halves. The cables are about a meter long, so I cut them to about 10 cm and soldered on replacement 3/32" submini phone jacks from RadioShack, part 274-298.

I think if I wired another pair, I would glue together the back shells first, drill a hole through them, and use this hole to route the wires (rather than using the above external route). And I might try to figure a way to leave on one of the huge clips so the thing doesn't dangle between my cameras.

Results: The power on/off, focus lock, and shutter release on either remote will now trigger both cameras. I had previously worked out some details of synchronizing digital cameras by examining video output from the cameras, and I have a little tester that shows me (at least the potential) electronic sync between the cameras. With the twin remotes, I can power up each camera at exactly the same time, and the cameras come up closely synced every time, although they stay closely synced for only a few minutes. Interestingly, the power button does not use a serial command to power up the camera--it merely shorts the signal and ground lead--thus does not have serial/video sync issues like the rest of the functions. (Power down is a serial command however.) On initial power up, exposures appear to be very tightly synced, though I have only done preliminary testing.

The Pictures: Here are a few stereo images for your enjoyment. These pairs are big, 900x600, and I need to use a screen resolution of at least 1024x768 to view them on a web page. I apologize to those of you without broadband also--the compression is mild, because I can't stand to see JPEG compression artifacts in stereo. The stereo images here were obtained using a pair of Sony DSC-V1 cameras and a LANC Shepherd except where noted. These images all open in a new window. Optimized for screen resolution of 1024x768 or higher, 32 bit color.

Crossed View Parallel View 158k.
Old Fort Funston Park, above Ocean Beach, near San Fransciso, California.
Kurt Schmitt eases his own design R/C glider into the void and the waning light, with the ocean about 200 feet below.

Crossed View Parallel View 361k.
Nevada City, California.
In the fall, we get warm drenching storms lasting days, followed suddenly by cold fronts. The water freezes on everything through the night, but with the morning sun, the water evaporates rapidly in the dry air, and every surface exposed to the sun starts creating fog. Within a few hours, the evaporating moisture clouds up the sky, and the sun and fog are gone.

Crossed View Parallel View 300k.
Whitney Portal, along the eastern Sierras, California.
We hiked Mt Whitney starting at the portal at 2 AM, summitted, and returned to the portal by about 4 PM. Dave WinField is still smiling big with only a few miles left to go, although the rest of us were feeling some mighty sore feet by this point. Pair of Sony DSC-V1 cameras with right on-camera flash, using LED Sync Shepherd and twinned Sony remotes.

Crossed View Parallel View 110k.
Boreal Ridge Ski Resort, near Truckee, California.
I finally figured out how to be in the right place at the right time to capture a boarder in flight--just ask. This local snow boarder was amazing! He was happy to help me out, and effortlessly launched himself, getting some serious air with some jaw-dropping grabs.

Good luck,
Rob Crockett
Copyright 2008. All Rights Reserved.

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