ext microphone + remote shutter release = no joy

J

jaydil

Active member
Bought a GH1 last week. Overall...happy...720/60p video ROCKS. :2vrolijk_08:

BUT...I wanted to use the GH1 to do self-interview documentaries with a decent microphone (external, shotgun or lapel) AND a remote start/stop control. Inteviewee sits in the chair, presses a button to start recording, starts talking, presses button to stop. Simple, yes?

Unfortunately...no. :( The GH1 has a single jack for EITHER a microphone OR a remote shutter release. I am conversant with electronics...so I thought that MAYBE I could make it do both. Here is what I found:

  1. The remote shutter release uses the 3rd and 4th conductors on the jack, with 41K ohms to indicate presence of remote, 5K ohms for half press (focus), and 2K ohms for full press (shutter release). This is all documented on this web page:
    http://www.instructables.com/id/Panasonic-G1-GH1-Remote-Shutter-Release/
  2. The microphone input uses the 1st and 2nd conductors on the jack for stereo audio signal, and the 3rd and 4th conductors on the jack for ground, and to indicate the presence of the microphone. If the 4th conductor is not grounded (connected to the 3rd conductor @ 0 ohms resistance), the microphone is not recognized.
  3. The microphone is not recognized if "plugged in" while video is recording. I cannot make a switch that activates the shutter, and subsequently activates the external mic.

In brief..I cannot create a GH1 setup with an external mic, which allows an interviewee to start recording without touching the camera. That sucks. :(

Don't get me wrong, the camera is overall great so far. But I really REALLY wanted to use it for auto-interviews with a remote switch & good microphone.

Does anyone else know how this can be accomplished? If I missed something, please let me know.

My best hope is that there might be some way to activate recording/shutter with the "VIERA Link" (HDMI port), or perhaps with USB tethering (AV Out/Digital port). If anyone has hacked these interfaces. Unlikely, but it can't hurt to ask. :)

If you have any thoughts on this, PLEASE share. :beer:

J
 
Any why do you need remote start stop?

I suggest you to buy some small but very loud buzzer.
Instead of starting and stopping press this buzzer button and cut accordingly to big spikes on sound track.
Seems quite easy.
 
tester13 said:
Any why do you need remote start stop?

I suggest you to buy some small but very loud buzzer.
Instead of starting and stopping press this buzzer button and cut accordingly to big spikes on sound track.
Click to expand...
Here is an example:

Last weekend (in the USA) was Mother's Day.

We had a party from 11:00a-6:00p. 7 hours.

I wanted to set the GH1 on a tripod so anyone could record "Why I love my mother" or "Why I love being a mother" without any camera operator.

A 16GB SDHC card holds just 2 hours of 720/60p (SH mode).
A 32GB SDHC card holds 4 hours, still not enough.

And even if I could record 7 hours of 720/60p:

  1. Transcoding hours of footage for editing takes more hours and many more gigabytes of storage.
  2. I have no tools that automatically split footage based on an audio signal (do you??).

So a buzzer does not seem like a viable solution.

J
 
Your case seem to be quite special.
I do not talk about transcoding, I talk about cutting and this is very fast.
For any normal task without hundreds of people and 7hr footage buzzer will work fine.
I suggest you to buy HD camcorder for such tasks.
It is much better suited.
 
Where is the problem, to tell the people to press start at the camera, then sit down, tell their story and then, once they are finished, press stop again?

If they need to think or break in between, they can just lift their hands so you can see for editing, what they do not want to have recorded, as soon as the hand is down, you know, that the footage can be used again.
If you need an audio and video signal, they can clap in their hands to indicate the start and stop of the story.
If I understood right, the GH1 shall not run for 7 hours, but it shall be available all that time.

So with this, it still can be done with the external microphone.

Granted, that an remote control is a little bit more comfortable, buit I am sure, this will work fine.
 
i agree with AKED.

plus, people are used to pressing the button on the camera(usually their own cam, but hey, not much has changed from cam to cam). most people just need to be told where the button is, and it's easy. i've done the "press the button yourself" thing on my GH1, and if i don't think my friends/family can handle it, i stick a bright green sticker to the already large-enough "chromed" shutter button (not talking about the little red one on the back...the "chrome" one works just the same in video mode as well). the first time i threw in a remote shutter, i got 3 seconds in front of ALL my shots of people pointing the remote at the camera as they pressed the button. i'm not kidding. remotes make people wierd.
 
Thanks guys . . . I appreciate your replies. :dankk2:

tester13 --

Your suggestion (audio markers) seems like the best workaround, if remote shutter + microphone is technically impossible.

Continuous shooting with audio markers is not ideal, but I think I could live with these issues:
  1. A 32GB card fills up in 4 hours (assuming no artificial limit), so I'll have to swap cards at least once to record a full day. I probably want to check the setup every 2 hours anyway, so no problem. :thumbsup:
  2. Transcoding a 4-hour clip (for editing in Final Cut) will take 40x longer and 40x more disk space than transcoding a dozen 30-second clips. But this is for fun, no deadlines...and I have cpu time and disk to spare...so no problem. :thumbsup:
  3. Manual cutting on the audio markers is a minor hassle. Can you suggest software that will cut clips based on audio spikes? Otherwise I will forget about marking the clips, and just look for interviewees in the frame.

My only remaining concern is...will the GH1 tolerate continuous recording for a full day, at the highest bitrate?

I haven't used this camera enough to grok its long-run thermal management. High-bitrate HD video means serious number crunching...which means heat...and there are no vents or external heatsinks. So I wonder how much 8 hours of continuous operation will affect the sensor... :undecided

Regarding HD camcorders....I bought the GH1 because it does 720/60p and allows interchangeable lenses (eg 25mm f1.4 for shallow DOF). If you know of another HD camcorder that does 60p with a good selection of lenses, for $2000 or less, please tell me!

And hey...I just noticed your huge thread about firmware hacking!! Now I must read that thread, and perhaps donate... :)


AKED & Chris Light --

I appreciate your suggestions. However...asking a subject to press a button on the camera is not always an option:

  1. Many people are intimidated or distracted by complex machines. If a complicated AV recording setup is on a tripod 2m away, OK. Even better...hide it behind a panel with simple holes for lens & mic. If the subject has to approach & touch the machine, this could totally change their mindset. Technophiles get distracted. Technophobes get scared. I really don't mind cutting the 3 seconds where a subject holds a simple remote towards the camera. I care much more about the way they think & feel. If they have to look at a complicated piece of gear up-close, press a button, and run back to their chair...their world has changed. I want to minimize the "observer effect".
  2. At a friends & family event, there are often youngsters who can press a simple remote button and speak their mind...but who cannot reliably press a button on the camera due to complexity, height, sticky fingers, etc.
  3. At a more public event, the video setup may be locked in a box for safety & security reasons.

That's my thinking for now. I am a total newbee to this video stuff, so please go easy on me if I missed something important. :)


I'm still hoping that someone will hack one of the inputs to allow microphone + remote. In the meantime I'll run with tester13's suggestion. :thumbsup:

J
 
Last edited:
jaydil said:
I'm still hoping that someone will hack one of the inputs to allow microphone + remote. In the meantime I'll run with tester13's suggestion. :thumbsup:
Click to expand...

You do not need software hack, you just need to modify standard remote shutter (this thing costs below $8). To allow you to pass microphone signal after shutter activation.

P.S. You also do not want to transcode anything for cutting, as software like http://www.fame-ring.com/ exist.
 
This isn't a solution, but maybe a last minute option...use a recorder like the Yamaha CX to record all the audio. It has a standard 3.5mm jack for a mic, and will record for over 3 hours straight (then just stop/start to continue for another 3 hours), then use PluralEyes to sync the audio to the GH1's built-in mic in post. My biggest concern would be that people would actually be capable of actually starting the recording with the remote shutter release...let alone nail focus (if it was left on auto focus). I think the average person would be looking for a bright red LED on the front of the camera to show recording, even if the LCD was facing them...not to mention most would just sit there and wait for a "flash"...thinking it was a photo booth setup...at least that's what would happen at a wedding reception where I earn my "living" (for lack of a better term). lol
 
To Jaydil.

I think it is still possible to do this.
You need to control the shutter with a microswitch.
To the normally closed contacts you solder on a 2KOhm resistor.
These contacts will be wired to wires 3 and 4 on the 4 wire extension cord.
You will need the following parts (besides the microswitch) from Mouser Electronics.

2.5mm 4 conductor plug and cord assy (pt no 172-7425)
2.5 mm 4 conductor jack (pt no 161-6425)

The part number 172-7426 is a better choice than 172-7425 in that the plug is the 90 degree type.

Solder three wires - 1, 2, 3 from the jack to the cord.
Solder one wire from the microswitch to wire 4 of the cord and the other wire to conductor 4 of the jack, so the microphone's plug does NOT short wires 3 and 4.

Here is how it works.
The microphone is connected to the jack, from where wires 1, 2 and 3 go directly to the plug. Contact 4 of the jack goes to the microswitch where it is connected to wire 3 in the normal resting state of the switch.
When the switch is pressed, wires 3 and 4 are disconnected and have a 2 KOhm resistor connected across.

Note that this remote will work only when a three contact plug (from the microphone or a dummy) is inserted in the jack. To make it work without the microphone you would need to use the other normally open pair on the microswitch in conjuction with yet another switch to switchover the pairs for use with a mic or without.

Hopefully it makes sense to you.


Good luck.
 
Last edited:
tester13 said:
You do not need software hack, you just need to modify standard remote shutter (this thing costs below $8). To allow you to pass microphone signal after shutter activation.
Click to expand...

tyampel said:
To the normally closed contacts you solder on a 2KOhm resistor.
These contacts will be wired to wires 3 and 4 on the 4 wire extension cord.

The microphone is connected to the jack, from where wires 1, 2 and 3 go directly to the plug. Contact 4 of the jack goes to the microswitch where it is connected to wire 3 in the normal resting state of the switch.
When the switch is pressed, wires 3 and 4 are disconnected and have a 2 KOhm resistor connected across.
Click to expand...
Thanks guys...but I already tried this. :)

Summarizing from post #1:
1) The GH1 uses contact 3 to recognize either a microphone or remote shutter.
2) The GH1 does not recognize a microphone that is connected while recording.

I suspect the only way to have both remote & microphone is to control the camera through one of the other ports (HDMI or USB). Obviously the HDMI port supports at least the playback controls. I'm sure there is a more extensive "tethering" interface that Panasonic uses for product testing/QC.

tester13 -- If you stumble across any of that tethering/testing code in your firmware explorations, I'd love to know! Or...if you find a way to enable the "microphone connected" interrupt during video recording... :2vrolijk_08:

tyampel -- FYI, a 2K ohm resistor by itself will not activate the shutter. I tried it. The camera requires a higher resistance on contact 3 first. This circuit with 41K > 5K > 2K ohms works:
FUAXYBCFV15TSH1.MEDIUM.jpg


Here was my quick & dirty build of that circuit:
remoteshuttertest.jpg


J
 
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