[K David]

I just picked up a Miops noise/laser/lightning/etc trigger to use with my K-1 on an upcoming shoot. I was wondering if anyone knows if there's a cable release splitter and extender for the Pentax Cable Release that would let me use my K-3 at the same time but from a different vantage point.

[AstroDave]

It depends on how much of a load the Miops will sink, but a splitter and longer cord are as simple as the correct audio cords. The Pentax plug is a 2.5mm stereo audio plug. Take your Miops cable to, say, Best Buy and look for both an audio splitter (your cable plugs into one end, and there are two plugs on the other end that go to each of your cameras) and an extender audio cable (socket on one end, plug on the other). The 2.5mm socket and plug are smaller than standard audio - they (for things like your earphones) tend to be 3.5mm. You may need some 3.5 to 2.5 adapters. (I used to get all this stuff at Radio Shack - sob! I don't know if Best Buy has as wide a range of such things. If not, Ebay should be your friend.)

The Miops will probably handle the extra load for two cameras. If not, let me know - it's easy enough to build a little transistor switch that would handle as many output devices as you want!

[stevebrot]

The Miops will probably handle the extra load for two cameras. If not, let me know - it's easy enough to build a little transistor switch that would handle as many output devices as you want!

I would be hesitant to implement without circuit isolation between the cameras.


Steve

[AstroDave]

I would be hesitant to implement without circuit isolation between the cameras.

Easy enough - one more transistor!!

[K David]

but a splitter and longer cord are as simple as the correct audio cords

It never even occurred to me to use audio cable. That's a fantastic idea.

without circuit isolation

Basically some sort of galvanic isolation? I assume the concern is the grounds on the cameras having different potentials because they're different models with different on-board computers. That hadn't occurred to me (I assumed since they use the same batteries that the systems would all be the same.)

Easy enough - one more transistor!!

Would an in-line capacitor that passes AC and blocks DC do the trick?

[AstroDave]

Would an in-line capacitor that passes AC and blocks DC do the trick?

No, the switching is all DC - basically, to fire the camera (or a flash), you ground the shutter control.

And, don't worry about grounds ("galvanic isolation") - as long as all the grounds are connected, which will occur naturally through the ground portion of the cable shielding, no problem

[Not a Number]

A few diodes should do the trick.

Syncing shutter on a K20D and K100D - PentaxForums.com

[AstroDave]

A few diodes should do the trick.

Syncing shutter on a K20D and K100D - PentaxForums.com

That's a great reference. You can readily insert an extension cable in the switch leg of the last circuit shown in that article. I use a home-made one (just a 3 wire "twisted trio" I guess you'd call it) that is 25 feet long - no problem.

[stevebrot]

A few diodes should do the trick.

Syncing shutter on a K20D and K100D - PentaxForums.com

That's a great reference. You can readily insert an extension cable in the switch leg of the last circuit shown in that article. I use a home-made one (just a 3 wire "twisted trio" I guess you'd call it) that is 25 feet long - no problem.

Ta! Da!

Even after all these years (a full decade for me), this site continues to amaze me.


Steve

[stevebrot]

I would be hesitant to implement without circuit isolation between the cameras.


Steve

Syncing shutter on a K20D and K100D - PentaxForums.com

Quote from the linked thread...

Trying to get them both to fire from either one or two wireless transmitters has proved unreliable; splitting the connection from a wired remote doesn't work on this pair of cameras (once they're connected, both cameras start firing nonstop even if no button was pushed).

I was concerned about something like that or worse


Steve

[BarryE]

Have I missed something (probably) ... wouldn't the Pentax remote fire both at the same time, if that's what wanted ? I guess if they are widely separated that may be a problem, but the IR beam is not that narrow so maybe it would work ?

[K David]

wouldn't the Pentax remote fire both at the same time, if that's what wanted

It would, but I'll be triggering them with a MIOPS unit set to trigger on a loud noise or laser beam disruption.

[AstroDave]

It would, but I'll be triggering them with a MIOPS unit set to trigger on a loud noise or laser beam disruption.

You may still not be happy, depending on what you are triggering for. I'm thinking maybe you want to watch water-filled balloons bursting or something similar. If that is the case, you may find that shutter lag is a killer. Once you tell the camera to fire, via the remote cable, there is a delay of 70-90 milliseconds or so. I've measured this for my K-5 and K-3, but haven't done it for the K-1 yet. The way to make this work is to open the camera shutter, and then fire a flash via the Miops (I presume it can do that). My experience measuring flash delay puts the firing some 10s of microseconds after triggering.

I need to measure and properly report to the Forum on all this stuff!!

[K David]

The way to make this work is to open the camera shutter, and then fire a flash via the Miops (I presume it can do that). My experience measuring flash delay puts the firing some 10s of microseconds after triggering.

Yes, for studio work like balloons and water drops, that's the plan. The project I'm thinking of with two cameras would be for sparring and board breaking, so the delay wouldn't be a killer. I would also set it up with a laser break trigger and put the laser a half inch above the board to get the camera to trigger as the board is breaking.

[Class A]

I would also set it up with a laser break trigger and put the laser a half inch above the board to get the camera to trigger as the board is breaking.

If you use a Cactus LV5 as the laser trigger, it could trigger two Cactus V5 receivers (one for each camera) directly via radio.