S3IS hard wired hot shoe - Hotwire! Hardware Mods, Accessories and Insights - CHDK Forum supplierdeeply

S3IS hard wired hot shoe

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S3IS hard wired hot shoe
« on: 13 / December / 2010, 00:29:10 »

There doesn't seem to be any threads in this forum or anything specific on this subject when I search the rest of the internet.

I would open up my camera but it was recently repaired and working perfectly. I might get a camera for parts on ebay, fix it and then try to rig this up.

I don't like optical slave flashes. There must be a simple signal for the internal flash that can be tapped and used to fire the flash in the hot shoe. At most it should only require a diode, scr, opto-isolator or maybe just some wires. There shouldn't be any reason why a two or three way switch couldn't allow for selecting internal, external or both flashes to operate in sync with the shutter.

Has anyone given this a try yet?

Re: S3IS hard wired hot shoe
« Reply #1 on: 13 / December / 2010, 01:46:12 »
At one state Phyrephox was experimenting with flashing a led as an output which could be used to trigger a flash. I don't know if he is still active on the forum. Maybe if you posted a message Attention Phyrephox it may draw his attention.


Offline colinbm

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Re: S3IS hard wired hot shoe
« Reply #2 on: 13 / December / 2010, 04:54:54 »
Hi cantain
Have a look at SDM, they now support remote flash.

Hello thepanoguy, long time no see.


Re: S3IS hard wired hot shoe
« Reply #3 on: 13 / December / 2010, 06:13:34 »
You simply need a delay after switch release.

Choose capacitor value to give suitable delay depending on relay coil resistance.

See diagram below.

Re: S3IS hard wired hot shoe
« Reply #4 on: 13 / December / 2010, 07:02:44 »
Good idea. I have an S3IS. Up to now I have been time limited. I have an application which requires a remote flash. I will have to try SDM.

Hello colinbm,
I am slowly getting back to reading the forums. The first remote worked as expected.
« Last Edit: 13 / December / 2010, 07:13:17 by thepanoguy »

Re: S3IS hard wired hot shoe
« Reply #5 on: 14 / December / 2010, 18:14:13 »


thank you for the schematic. some questions:
1) is this USB triggered with CHDK commands?
2) or is it connected to a DIY remote trigger? re-reading your brief description made me think of that
3) why would we need a delay? shouldn't the signal be in sync with the shutter?
4) i thought a relay might react more slowly than an optoelectronic coupler. what's your experience using a relay in this application?

thanks for the lead and i'll look into it, but my preference is go as direct as possible, as in hard-wired into the flash circuit of the camera.

i was thinking about replacing the S3 pop-up flash and i'll start another thread on that.


thanks for the lead about SDM. i was never aware that it existed. it seems we have a lot of areas to experiment in with these cameras.


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