Clueless noob trying to make PW/Skyport shutter release adapter

[Curtis N]

Ok I have
Adidt remote cable w/ 3/32 stereo jack
3/32 stereo plug (which I can use on my 300D or plug into the Adidt remote)
1/8 mono plug for skyport receiver

I have identified which wire is which on the 3/32 stereo plug (one each for half-press, full-press and a common ground)

What I need to know is how to connect them to the 1/8 plug.
(with a soldering gun, dumbarse!)
Ok I know that much.

It seems the camera will fire simply by grounding the wire for full press without touching the wire for half-press. But I have heard about also grounding the half-press wire to "keep the camera awake" or something like that.

I do want to be able to use the remote camera in Av or Tv mode so that it meters each shot in changing conditions, if that makes a difference.

Any instruction or explanation would be greatly appreciated.

Edit: If you want to skip the confusion and go right to my conclusion, go to post #20 (http://photography-on-the.net/forum/showpost.php?p=4592294&postcount=20).

[b1gdaddy]

Try here >>>>> http://www.flickr.com/photos/8456144@N07/2130604010/in/set-72157600415521015/

If this is what you mean, it appears the switch will ground the focus cable but not permenantly. So connect the shutter release cable to the 1/8 plug & the focus cable to ground via switch.

[dch0719]

half press is tip and sleeve. shutter is ring and sleeve. I don't know if that's what your looking for.

Dan

[PacAce]

Ok I have
Adidt remote cable w/ 3/32 stereo jack
3/32 stereo plug (which I can use on my 300D or plug into the Adidt remote)
1/8 mono plug for skyport receiver

I have identified which wire is which on the 3/32 stereo plug (one each for half-press, full-press and a common ground)

What I need to know is how to connect them to the 1/8 plug.
(with a soldering gun, dumbarse!)
Ok I know that much.

It seems the camera will fire simply by grounding the wire for full press without touching the wire for half-press. But I have heard about also grounding the half-press wire to "keep the camera awake" or something like that.

I do want to be able to use the remote camera in Av or Tv mode so that it meters each shot in changing conditions, if that makes a difference.

Any instruction or explanation would be greatly appreciated.
If you want to keep the camera awake all the time (also drains the battery), then you will need to short the half-press wire to ground when the cable is used with your remote trigger. If you want the ability to meter each shot, then you'll need to use a metering mode other than Evaluative if AF mode is set to OneShot.

[b1gdaddy]

Excuse crude drawing. Hope this is what you are after.

[PacAce]

half press is tip and sleeve. shutter is ring and sleeve. I don't know if that's what your looking for.

Dan

Excuse crude drawing. Hope this is what you are after.

Looks like you two have conflicting information re which is focus and which is shutter. :confused:

[Curtis N]

half press is tip and sleeve. shutter is ring and sleeve. I don't know if that's what your looking for.Thanks, Dan. I have figured out that much.

What I don't know is if, when triggering via Skyport, do I need half-press at all, should I twist those wires together so the shutter button is in a state of continual half-press, or connect the half-press and full-press wires so the Skyport makes both connections simultaneously?

b1gdaddy thanks for the link, I'll check it out.

[b1gdaddy]

Looks like you two have conflicting information re which is focus and which is shutter. :confused:

http://www.peeters.com/300d.html

This is how I wired my homemade release.

[SkipD]

Excuse crude drawing. Hope this is what you are after.The drawing is NOT for the xxD series cameras. They use the special plug shown in Curtis' post rather than the "stereo" plug for the remote connection to the camera. The Digital Rebel series uses the "stereo" plug, but not the 20D/30D/40D.

[Curtis N]

http://www.peeters.com/300d.html
This is how I wired my homemade release.His two images are conflicting. The first one indicates the tip as the shutter contact, but the second one indicates the ring and sleeve connected to the shutter switches.

[b1gdaddy]

The drawing is NOT for the xxD series cameras. They use the special plug shown in Curtis' post rather than the "stereo" plug for the remote connection to the camera. The Digital Rebel series uses the "stereo" plug, but not the 20D/30D/40D.



Ok I have
Adidt remote cable w/ 3/32 stereo jack
3/32 stereo plug (which I can use on my 300D or plug into the Adidt remote)
1/8 mono plug for skyport receiver



300D?

[dch0719]

My mistake. b1gdaddy's right. tip - shutter and ring -af meter.
You would have to tie the ring and sleeve together to use the metering and autofocus and as PacAce said that would use the battery. In Manual no problem just fire the shutter.

Dan

[b1gdaddy]

His two images are conflicting. The first one indicates the tip as the shutter contact, but the second one indicates the ring and sleeve connected to the shutter switches.

You're right, 1st image is the correct wiring. Just confirmed this by metering my own release. Tip - Shutter, Ring - Focus.

[PacAce]

http://www.peeters.com/300d.html

This is how I wired my homemade release.

Hmm, it looks like you even have a conflict with yourself. :D Take a look at your diagram. in one, you have the tip as the shutter. And in the other, you have the tip as focus.

[b1gdaddy]

Hmm, it looks like you even have a conflict with yourself. :D Take a look at your diagram. in one, you have the tip as the shutter. And in the other, you have the tip as focus.

Ahh but that is not my drawing, merely a link to somebody elses (wrong ;)) work!!.

You're right, 1st image is the correct wiring. Just confirmed this by metering my own release. Tip - Shutter, Ring - Focus.

[Curtis N]

If you want to keep the camera awake all the time (also drains the battery), then you will need to short the half-press wire to ground when the cable is used with your remote trigger. If you want the ability to meter each shot, then you'll need to use a metering mode other than Evaluative if AF mode is set to OneShot.I guess I haven't figured out the need to keep the camera awake.

By simply shorting the shutter contact with the ground (tip and sleeve), the camer fires pretty much instantly. In Av mode it will meter each shot. I figure I will prefocus manually and switch the lens to MF so I don't see that as an issue either.

Could it be that the Skyport doesn't keep the circuit closed long enough to trip the shutter if the camera isn't already awake?

[PacAce]

I guess I haven't figured out the need to keep the camera awake.

By simply shorting the shutter contact with the ground (tip and sleeve), the camer fires pretty much instantly. In Av mode it will meter each shot. I figure I will prefocus manually and switch the lens to MF so I don't see that as an issue either.

Could it be that the Skyport doesn't keep the circuit closed long enough to trip the shutter if the camera isn't already awake?
With the newer camera going from sleep mode to wake mode almost instantly, I guess there really isn't a need to keep the camera awake while it's being operated remotely. With the lens in MF mode, "shutter lag" won't really be an issue, either.

The Skyport should keep the shutter closed for as long as you have your thumb on the transmitter trigger button.

[FlashZebra]

Curtis,

Take this blog entry by Ryan Dlugosz for a test drive.

http://blog.rrdphoto.com/2007/05/how-to-pocketwizard-remote-camera.html

Enjoy! Lon

[Curtis N]

Thanks for that, Lon.

I think I'll just leave the half-press circuit open for now. I'll report back if I determine that was a bad idea.

[Curtis N]

Ok I went through some frustrating soldering and testing. I wired it with the half-press circuit open and it was a bust. It didn't work at all on the 300D, and on the 20D it would only work if you hit the test button twice within a few seconds. It seemed like it needed one shot to wake up the camera and a second shot to trigger the shutter. But I could never get the camera to fire with consecutive hits, only every other hit. Weird. I couldn't figure it out because I was able to make it work earlier by just touching the wires together.

Anyway, I was tired of trying to solder microscopic wires so I decided to try a simple adapter similar to the one used in the link Lon posted above. Here are the results:

* Either a mono or stereo adapter will have the effect of keeping the half-press circuit closed as long as it's connected to the PW/Skyport mono miniplug (so get the mono version - it's cheaper).
* With this adapter and the Adidt shutter cable, I could trigger the 30D in either single shot or burst mode. The 20D would only fire once in single shot mode. I had to switch to burst mode to get the 20D to fire repeatedly. I have no idea why they behave differently.
* The Skyport system does not keep the shutter circuit closed if the test button is held down. It apparently closes the circuit for only a brief period, and you need to press the test button repeatedly to get multiple shots.
* The 3/32 plug fits right into the shutter cable jack on the 300D, but I could not get the Skyport to fire the camera. It would fire when I shorted the contacts on the other end of the cord, so I don't know why the Skyport won't work. Maybe it needs the circuit to stay closed for a certain period of time?

Just one other note to anyone who might try this setup: If you want to use one of the autoexposure modes so the camera can adjust to changing light, you can't use custom function 4-1. With this setting, the camera will lock exposure when the half-press circuit is closed. Autofocus is probably not a good idea either, so just switch to custom function 4-3 and it'll work fine.

Bottom line - Here's what you need to trigger a remote camera with a PocketWizard or Elinchrom EL-Skyport system:
1 - Cheap knock-off shutter release cable with a 3/32 stereo jack. These are often sold under the "Adidt" brand name, though identical units are available from Ebay merchants like Gadget Infinity (http://stores.ebay.com/Gadget-Infinity) for about $15 shipped.
1 - Mono adapter 1/8" to 3/32" ($2.99 at Radio Shack).

[In2Photos]

Dumb question but can't you just set the camera to not shut down automatically?

[Curtis N]

I thought so.

And I could make it fire by closing the full-press circuit but not the half-press circuit, just touching the wires together.

But with The Skyport, it won't fire unless the half-press circuit is closed.

I don't know about PocketWizards.

[In2Photos]

I thought so.

And I could make it fire by closing the full-press circuit but not the half-press circuit, just touching the wires together.

But with The Skyport, it won't fire unless the half-press circuit is closed.

I don't know about PocketWizards.
OK. Can you tie the two (half press and full press circuits) together using a diode?

[Aaagogo]

the forum members can always count on you Curtis,

thanx very much for your experiment for 1 was close on embarking on trying to wire the remote for my 30D and PW's.

thanx Curtis

[Curtis N]

OK. Can you tie the two (half press and full press circuits) together using a diode?As soon as you start using words like diode, you're beyond my knowledge of electronics.

[In2Photos]

As soon as you start using words like diode, you're beyond my knowledge of electronics.
Gotcha. Diodes are very easy, simple components. They allow current to flow one direction, but not the other. So in essence you could tie the two circuits together. The half press circuit would be activated during both half press and full press, but the full press circuit would only be activated during the full press of the remote. If you like I could try and draw something up for you? They can be found at any electronics parts store and are cheap.

[Curtis N]

Thanks, Mike.

I thought about wiring the two circuits together so the Skyport would close them both, but I got tired of trying to strip and solder wires that consisted of three tiny copper strands.

It's time for someone with more skills than me to do some experimenting.

[b1gdaddy]

Thanks, Mike.

I thought about wiring the two circuits together so the Skyport would close them both, but I got tired of trying to strip and solder wires that consisted of three tiny copper strands.

It's time for someone with more skills than me to do some experimenting.

Send me your skyports & i'll experiment for hours ;):p

[In2Photos]

Thanks, Mike.

I thought about wiring the two circuits together so the Skyport would close them both, but I got tired of trying to strip and solder wires that consisted of three tiny copper strands.

It's time for someone with more skills than me to do some experimenting.
Time to buy a small breadboard. Then solder some small solid "jumpers" to your wires that you can reuse over and over (or use alligator leads).

But I agree with b1gdaddy. Send me your skyports. ;)

[Lotto]

Curtis, I had similar finding when I was playing with my 20D and the eBay trigger. I managed to have the full press and half press on the same cable, by having a mono and stereo on each end.

http://farm1.static.flickr.com/217/551044316_f93a427abf_o.jpg

Using the mono end toward the camera will function as 'half press on', stereo end to camera acts as 'no half press'.
http://farm1.static.flickr.com/252/551044234_09aedba502.jpg

[coorz]

Someone should sticky this into the DIY section.
Here's my go at Skyport to 5D camera trigger; slaughtered a cheapo RS-80N3 knockoff and soldered a 3.5mm stereo jack to it. Works a charm and about 5 minutes work.
I only soldered the shutter release wire and left the half press wire unconnected.

http://www.displayfreak.com/5d/sky25d.jpg

[jrsforums]

Hey, Curtis....maybe I am missing what you are trying to do here.....seems you are trying to get a low cost wireless shutter using existing PW/Skyports...without the expensive paramount cord "motor drive" connector.

Why not just get a ~$27. wireless shutter, such as this...
http://cgi.ebay.com/Phottix-Wireless-Remote-Set-C3-for-Canon-20D-30D-40D-5D_W0QQitemZ200187588824QQihZ010QQcategoryZ43443QQ tcZphotoQQcmdZViewItem

I have 2 and they work great. I found the Phottix better than the Gadget Infinity one I had earlier (http://cgi.ebay.com/Wireless-Shutter-Release-for-Canon-EOS-40D-30D-5D-1Ds_W0QQitemZ170181351261QQihZ007QQcategoryZ64345Q QssPageNameZWDVWQQrdZ1QQcmdZViewItem )

[Curtis N]

Lotto and coorz, thanks for the input. Lotto, your design is pure genius! Unfortunately I was unable to make the system work with the half-press circuit left open. I guess I need to figure out why.

John, I actually own and use the Gadget Infinity unit you linked to. What I'm trying accomplish by using the Skyports is three-fold:
1) increased range vs. the Gadget Infinity set
2) the ability to fire two cameras at once by putting the Skyport transmitter on the hotshoe of one. For example, a remote camera at the balcony rail covering the whole stage while I shoot individual performers from below.
3) a system that also works on my old 300D (with its stereo sub-mini connector).

[icestrike]

coorz,
may i ask
how did you soldered the 3.5mm stereo jack to the RS-80N3?
just pull the controller from the wire, den at e end of it, soldered to the jack?

[coorz]

coorz,
may i ask
how did you soldered the 3.5mm stereo jack to the RS-80N3?
just pull the controller from the wire, den at e end of it, soldered to the jack?
Correct.
However i did some more testing last night and found the following issues;
- I use Cfn.4-1, in this mode i can trip the camera no problem, i just pre-focus and trip it remotely. If you're not using that Cf then it won't trip as i have not connected the half-press wire
- the funny thing is that when i press and hold the Skyport test button longer it looks like it is doing a half-press (viewfinder bottom status screen pops up). After that i can trip it but it seems intermittent, sometimes i have to fire twice.

So definately not 100% working as it should.

[Blackey Cole]

Lotto, it seems you read my mind about using the cheap eBay triggers.

I have had excellant results with the 16 channel ones, never had a miss fire or any other problem with using them with my Vivitar 285's.

Are you using the flash triggers or the shutter trigger, the receiver you show is identical to the ones I have for flash. Even the RD616 number on my flash triggers. I have two of them with two more enroute from China. When I am able to get my 40D I was hoping to use the 300D as a remote camera shooting as I shoot the 40D from a different angle and if the flash trigger receivers work then I will not need to get the shutter release trigger setup sinc eit seems to usee the same receiver at least.

[ben_r_]

Someone should sticky this into the DIY section.
Here's my go at Skyport to 5D camera trigger; slaughtered a cheapo RS-80N3 knockoff and soldered a 3.5mm stereo jack to it. Works a charm and about 5 minutes work.
I only soldered the shutter release wire and left the half press wire unconnected.

http://www.displayfreak.com/5d/sky25d.jpg
Thats the same thing I made.

[Aaagogo]

i'm trying to figure out how to test which wire corresponds to the pin in the plug.

can you stick like a thin metal wire into the plug and then use a multimeter and test for continuity?


Someone should sticky this into the DIY section.
Here's my go at Skyport to 5D camera trigger; slaughtered a cheapo RS-80N3 knockoff and soldered a 3.5mm stereo jack to it. Works a charm and about 5 minutes work.
I only soldered the shutter release wire and left the half press wire unconnected.

http://www.displayfreak.com/5d/sky25d.jpg

[coorz]

i'm trying to figure out how to test which wire corresponds to the pin in the plug.

can you stick like a thin metal wire into the plug and then use a multimeter and test for continuity?
Yes but i wouldn't bother with that.
Connect the N3 cable to the camera, cut off the cable, strip a bit off the wires and short them one by one, them you'll find out which is GROUND, halfpress and shutter release.

Or much easier just take apart the remote and use you multimeter to check which wire is what.

[Aaagogo]

ah har... now why didn't i think of that...:lol:

ok, now for the next qn.

the PW side, does it matter which one goes to the sleeve and which one goes to the tip on the plug?

I would think that it shouldn't matter right, since either way, it "closes" the switch and completes the connection.

Yes but i wouldn't bother with that.
Connect the N3 cable to the camera, cut off the cable, strip a bit off the wires and short them one by one, them you'll find out which is GROUND, halfpress and shutter release.

Or much easier just take apart the remote and use you multimeter to check which wire is what.

[coorz]

The GROUND wire goes to the sleeve, shutter release wire should be wired to the tip.

[MT Stringer]

When y'all get this all figured out, maybe one of you can make me one that will work with my 20D and Skyport. Me an soldering irons don't get along very well. I'm much more at home in the garage with a hammer and a drill! :D
Mike

[james048a]

subscribing to thread.
This looks pretty cool idea of remote triggering a 2nd camera as you use the 1st on.

[Aaagogo]

interesting response i got from Gadget Infinity,

I was asking them if there's combined shipping and also they sent me a personalized thank you note, so i told them that i will buy more cables once i test them out to work on my pocketwizards.

This was the reply - " I'm sorry our plug cannot work with Pocket Wizard. Sorry about that. "

[Aaagogo]

i got a issue...

i got the gadgetinfinity remote for my 30D, but the moment i plug in the 1/8 to 3/32 adapter, the camera activates the autofocus, i tried both the stero and mono adapter, and they gave me the same issue...

could it be the plug or the remote???

[SkipD]

I just started playing with this idea this morning. I cobbled together a test rig which emulated the wiring done by Coors (post #31 above). The results, using one of my Skyport universal transmitter & receiver combinations, were not exactly what I had hoped for.

My 20D is set up with Custom Function 4 = 1 so that autofocus only works when I want it to. I used the "M" mode for exposure control. My hope was that, with these settings, I didn't need a "half-press" switch contact.

I had to push the "test" button on the transmitter twice or even three times to get the camera to fire, but since the Skyports work so rapidly I could almost get away with this method. However....

I let the 20D time out and shut itself down. Of course, tapping the half-press of the shutter release button will "awaken" the sleeping 20D. The remote setup - connected only to the full-press contact - would not bring the camera back to life.

I tried tying the "half-press" and "full-press" wires together and shorting both to ground at the same time, triggered from the Skyport, but this did not work at all.

I also tried shorting the "half-press" wire to "ground" full-time. That would work for one shot, but the "half-press" circuit must be opened before the camera can be triggered a second time.

My plan is to design and build a small interface circuit that would go between the Skyport receiver and the cable that plugs into the camera. My circuit would by triggered by the Skyport receiver triggers, and then it would instantly close the "half-press" circuit and a few milliseconds later would close the "full-press" circuit and then open both - just like the camera's shutter button (and the remote manual switch) works. I will be able to control not only the sequence of the contact closures, but the length of time the contacts are closed with this circuit. This interface circuit should totally resolve the issues with using a single-contact switch to trigger the camera.

I just measured the voltages on the two switch circuits, and the voltages are different. The "half-press" circuit is at about 4.5VDC while the "full-press" circuit is at about 3.3VDC.

As a prelude to designing the fancy circuit, I tried some diode isolation to, hopefully, allow me to trigger both the "half-press" and "full-press" circuits at the same time but keeping them electrically isolated. This did not work at all. While the diode isolation seemed to work OK when physically shorting the circuits together, I could not get the camera to trigger via the Skyport receiver at all with a diode in the circuit.


To be continued......

[PacAce]

I just started playing with this idea this morning. I cobbled together a test rig which emulated the wiring done by Coors (post #31 above). The results, using one of my Skyport universal transmitter & receiver combinations, were not exactly what I had hoped for.

My 20D is set up with Custom Function 4 = 1 so that autofocus only works when I want it to. I used the "M" mode for exposure control. My hope was that, with these settings, I didn't need a "half-press" switch contact.

I had to push the "test" button on the transmitter twice or even three times to get the camera to fire, but since the Skyports work so rapidly I could almost get away with this method. However....

I let the 20D time out and shut itself down. Of course, tapping the half-press of the shutter release button will "awaken" the sleeping 20D. The remote setup - connected only to the full-press contact - would not bring the camera back to life.

I tried tying the "half-press" and "full-press" wires together and shorting both to ground at the same time, triggered from the Skyport, but this did not work at all.

I also tried shorting the "half-press" wire to "ground" full-time. That would work for one shot, but the "half-press" circuit must be opened before the camera can be triggered a second time.

My plan is to design and build a small interface circuit that would go between the Skyport receiver and the cable that plugs into the camera. My circuit would by triggered by the Skyport receiver triggers, and then it would instantly close the "half-press" circuit and a few milliseconds later would close the "full-press" circuit and then open both - just like the camera's shutter button (and the remote manual switch) works. I will be able to control not only the sequence of the contact closures, but the length of time the contacts are closed with this circuit. This interface circuit should totally resolve the issues with using a single-contact switch to trigger the camera.

Before I work on that circuit, though, I may try some diode isolation to allow me to trigger both the "half-press" and "full-press" circuits at the same time but keeping them electrically isolated. Has anyone played with this idea yet?

I just measured the voltages on the two switch circuits, and the voltages are different. The "half-press" circuit is at about 4.5VDC while the "full-press" circuit is at about 3.3VDC.

To be continued......
Skip, when you say that shorting the focus wire full time only allows you to fire the shutter once, are you talking about when the camera is in sleep mode, or do you mean it works like that all the time? The reason I ask is that you should be able to pre-trigger the camera by shorting the focus wire and take as many shot as you wish without the need to unshort the focus wire between shots. I have my N3 cable wired so that when I plug a PW mono minijack cable to it, is shorts the focus wire full time and I haven't had any problems with it.

Re using the isolation diode, here's a link where someone did the same thing:

http://www.iaw.com/~pturton/remote/index.htm

[SkipD]

Skip, when you say that shorting the focus wire full time only allows you to fire the shutter once, are you talking about when the camera is in sleep mode, or do you mean it works like that all the time? The reason I ask is that you should be able to pre-trigger the camera by shorting the focus wire and take as many shot as you wish without the need to unshort the focus wire between shots. I have my N3 cable wired so that when I plug a PW mono minijack cable to it, is shorts the focus wire full time and I haven't had any problems with it. You may have a different camera, but with the 20D (again, with CF4=1 and M mode), if I ground the "focus" (what I called "half-press" above) permanently then ground the "full-press" wire the camera will fire. Then I disconnect the "full-press" wire and reconnect it hoping to fire again but nothing happens until I un-ground and re-ground the "focus" wire. This is all with physical connections of the wires coming from the plug which is connected to the camera.

When I used diode isolation and manually made the connections between the ground wire and the common connection of the two diodes I would get the camera to fire every time. However, the Skyport receiver would not trigger the camera with the diode(s) in the circuit.

[PacAce]

You may have a different camera, but with the 20D (again, with CF4=1 and M mode), if I ground the "focus" (what I called "half-press" above) permanently then ground the "full-press" wire the camera will fire. Then I disconnect the "full-press" wire and reconnect it hoping to fire again but nothing happens until I un-ground and re-ground the "focus" wire. This is all with physical connections of the wires coming from the plug which is connected to the camera.

I have the 30D and tried it with CF4=1 and M mode and it works just fine for me as I would expect it to. And the same goes for my other cameras, too (1D series). Not sure why your 20D is giving you a problem. I wonder if there's something the matter with your cable. Perhaps there's some sort of high resistance short between the focus wire and the shutter wire. Easy enough to test for with a VOM.


When I used diode isolation and manually made the connections between the ground wire and the common connection of the two diodes I would get the camera to fire every time. However, the Skyport receiver would not trigger the camera with the diode(s) in the circuit.
Hmmm, interesting.

[SkipD]

I have the 30D and tried it with CF4=1 and M mode and it works just fine for me as I would expect it to. And the same goes for my other cameras, too (1D series). Not sure why your 20D is giving you a problem. I wonder if there's something the matter with your cable. Perhaps there's some sort of high resistance short between the focus wire and the shutter wire. Easy enough to test for with a VOM.There are no shorts in the cable. I did find (as I wrote above) that the two circuits in the camera present different voltages to the remote control socket. Is that the same with your 30D? It's possible that the interface circuitry is different in the 20D relative to other cameras and that could be the bugaboo I am playing with.

It seems that the Skyport switching circuit may be limited somehow and that could be why it won't trigger the camera through diodes.

Though I originally was thinking of using a couple of little solid state timers such as the 555 (or one 556 timer), I'm now thinking of using a really simple circuit that would have the Skyport receiver switch turn on a pair of transistors, one for each of the camera's switching circuits. There would be a time delay (simple R-C network) after the transistor that triggers the "full-press" circuit which would then turn on a final transistor to trigger the camera a few milliseconds after the "half-press" circuit was triggered.

[PacAce]

There are no shorts in the cable. I did find (as I wrote above) that the two circuits in the camera present different voltages to the remote control socket. Is that the same with your 30D? It's possible that the interface circuitry is different in the 20D relative to other cameras and that could be the bugaboo I am playing with.

It seems that the Skyport switching circuit may be limited somehow and that could be why it won't trigger the camera through diodes.

Though I originally was thinking of using a couple of little solid state timers such as the 555 (or one 556 timer), I'm now thinking of using a really simple circuit that would have the Skyport receiver switch turn on a pair of transistors, one for each of the camera's switching circuits. There would be a time delay (simple R-C network) after the transistor that triggers the "full-press" circuit which would then turn on a final transistor to trigger the camera a few milliseconds after the "half-press" circuit was triggered.
I have 3.26V across the shutter and ground and 4.44V across the focus and ground.

Re the 20D having a different interface, I don't think it would. Do you have a wired remote control? If you do, you should be able to test if the camera behaves the same when with it also. The way it normally is supposed to work, if you press the button on the remote all the way, it should take one picture if the camera is in single frame mode. You should then be able to ease up on the button so that the shutter is no longer pressed but the focus button is (half pressed). If you then press the button all the way again, the shutter should release again and take another picture. The way your camera is behaving, I have a feeling it's not going to do that either.

BTW, did you say that when you ground the focus wire full time, you can't shoot more than one frame even when using the Skyport to trigger it instead of you manually shorting the shutter wire? If seem like you're going through a lot of trouble (with the building of your "interface" circuit) to get your camera to work in wireless remote mode when it really shouldn't be necessary.

[SkipD]

Folks, I have finally completed design and construction of a switching circuit to adapt one of my Elincrom EL Skyport universal receivers to trigger my 20D remotely. It works superbly. It will even wake up a "sleepy" camera with one press of the test button on the transmitter.

I built the circuit using a single 556 IC (dual timer) chip (available from Radio Shack), though it could easily be built with two 555 chips. All the rest of the components should be available at Radio Shack, but I used what I had in my parts collection.
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If anyone is really interested in seeing my finished product (housed in a plastic Sucrets box), I can photograph it sometime in the future. Right now, though, I don't have time for that.

Note that the diagram of the N3 plug is just that - the PLUG. The contacts shows are seen when looking at the end of the plug.

[claybuster]

I don't know why I even looked at the diagram,it looks like a street map or the floor plan for the first floor of a building to me. Electronics is not my strong point:D