How to control a LED panel with a Stackshot Controller

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Louis L.
Posts: 3
Joined: Wed Jan 07, 2015 9:11 am
Location: Adelaide

How to control a LED panel with a Stackshot Controller

Post by Louis L. »

Dear All,

How do you manage the heat generated by the LED panels?

I would like to submit a problem that I haven’t manage to solve on my own -yet... :

My macrophotography setup includes a 15W LED that generates a lot of heat.
To decrease that heat, I would like to switch the LED ON while taking the shot and OFF between the shots.

The shots are automated through a Cognisys Stackshot, piloted by Zerene: the camera receives a first electric pulse from the Stackshot controller to lift the mirror (I am using a Nikon DSLR), then a second to trigger the shutter.
Ideally, I would like to switch the LED ON at the second pulse from the controller, and keep it ON until the shot is taken.

So far, I have thought about using a “self-locking switch relay module”, that would be installed on the lead that control the camera. I believe this module would detect the pulses transiting through the cable and close the secondary circuit (which feeds the LED) at the first pulse and open it at the second pulse, switching the LED OFF.
However, if the LED is turned OFF at the second pulse, then it is OFF while the shot is being taken, which does not really help me solve my problem :( Unless I can integrate some sort of timer...

Is there someone that had faced similar issue, and what option was chosen?

Thank you very much!

Regards

Louis
Louis Lignereux

physicsmajor
Posts: 94
Joined: Sun May 10, 2020 12:56 pm

Re: How to control a LED panel with a Stackshot Controller

Post by physicsmajor »

Two main approaches:

Control the heat with newer, more efficient panels providing similar light output obviating the need to toggle. This seems possible as panels well above 15W run quite cool today, and it's a more elegant solution.

Alternatively, purchase a solid state relay and connect the light's power through it. You want a relay comfortably over-rated for the amperage. You'll then want to control the relay from an Arduinio which you program to watch for the Stack Shot signal and turn the light on between or just stop listening for a set duration (a couple seconds) when any is observed.

Louis L.
Posts: 3
Joined: Wed Jan 07, 2015 9:11 am
Location: Adelaide

Re: How to control a LED panel with a Stackshot Controller

Post by Louis L. »

Hi physicsmajor,

thank you for your input,
physicsmajor wrote:
Tue Apr 19, 2022 10:02 pm
Two main approaches:

Control the heat with newer, more efficient panels providing similar light output obviating the need to toggle. This seems possible as panels well above 15W run quite cool today, and it's a more elegant solution.

I'll keep the 15W LED that I have: it is a 12cm annular cob LED that I have DIYed into a dome illumination system. I am hoping to get a good light source out of it, and possibly shoot at higher shutter speed.

I also thought about installing a heat sink + fan, but it would add a lot to the size and possibly create some undesired air disturbances.
physicsmajor wrote:
Tue Apr 19, 2022 10:02 pm
Alternatively, purchase a solid state relay and connect the light's power through it. You want a relay comfortably over-rated for the amperage. You'll then want to control the relay from an Arduinio which you program to watch for the Stack Shot signal and turn the light on between or just stop listening for a set duration (a couple seconds) when any is observed.

I will look into that Arduino option, and keep posted if I find a satisfactory solution.

Cheers
Louis Lignereux

Macro_Cosmos
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Re: How to control a LED panel with a Stackshot Controller

Post by Macro_Cosmos »

I would modify the LED panels, using cheap heatsinks with cheap thermal pads with active cooling using a fan should significantly decrease the issue. Get rid of the shell too.
The problem with turning the LED light on and off would be colour temperature variation. It is by all means minute, but we are speaking about several hundreds of shots here.
It takes some amount of time for any light source to reach a steady-state of colour temperature and output intensity. You can run a relay circuit that is powered by the controller too, but that fails to address the core issue, heat.
(And frankly, poor design of the panels.)

BugEZ
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Location: Loves Park Illinois

Re: How to control a LED panel with a Stackshot Controller

Post by BugEZ »

I currently use pulsed LED lighting that switches on during the exposure window. With my rig the shutter is open ~3 seconds. The LED light comes on about 125msec after the shutter opens and is timed to stay on for two seconds, The light then switches off. The shutter closes with the light off. My camera is mirrorless, but not shutterless. The .125 msec delay allows the shutter bounce to settle.

I have accomplished this pulsed lighting with two methods. Originally I designed a circuit using the classic 555 timer integrated circuit. This circuit is triggered by the strobe contacts interfaced via the hot-shoe. Two wires from the hot-shoe go to the circuit. Trigger. It was tricky to adjust this circuit via tiny potentiometers (delay and pulse duration independently adjusted) and was a bit giddily as my electronic construction was a bit sloppy. But it has worked on my main rig for about 1K stacks of 100-300 images.

A much improved method is to use a stand alone programmable module for the LED drive pulse. It runs off of 5V (USB supply works fine). It is triggered by the hot-shoe contacts and switches a relay that drives the LED. This is about a $15 module. I used this when making time lapse movies of larva in a tiny terrarium and made about 750K exposures with no difficulties.

So, in this embodiment, the StackShot does not drive the light pulse. The camera triggers the pulse via the hotshoe.

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Aloha

BugEZ
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Location: Loves Park Illinois

Re: How to control a LED panel with a Stackshot Controller

Post by BugEZ »

This is a link on Amazon to the programmable relay module I used. The price has dropped by a few dollars since I last purchased one. I purchased several and also use them as intervalometers in time lapse and to regulate watering of terrariums.


https://www.amazon.com/UCTRONICS-Progr ... ljaz10cnVl

Keith

Chris S.
Site Admin
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Re: How to control a LED panel with a Stackshot Controller

Post by Chris S. »

Keith, thanks for both posts. I've long been meaning to switch from continuous halogen to gated LED COBs, but have put it off. My thought was to intercept the signal from the StackShot's trigger cable, program a delay using an Arduino, then have the Arduino trigger a relay to keep the LED COBs on for a programmable length of time. Not rocket science, but a chore.

Your approach is much simpler. Must admit I felt a head-slap moment upon reading your post. Of course the hot shoe contacts can be used to trigger the lights--that's their basic job description. Why do good ideas so often seem obvious only after someone else has pointed them out?

Cheers,

--Chris S.

physicsmajor
Posts: 94
Joined: Sun May 10, 2020 12:56 pm

Re: How to control a LED panel with a Stackshot Controller

Post by physicsmajor »

BugEZ wrote:
Wed May 11, 2022 2:29 pm
This is a link on Amazon to the programmable relay module I used. The price has dropped by a few dollars since I last purchased one. I purchased several and also use them as intervalometers in time lapse and to regulate watering of terrariums.


https://www.amazon.com/UCTRONICS-Progr ... ljaz10cnVl

Keith
This is a FRM01 relay module and if anyone is interested in a 3D printed enclosure for safety and easier mounting, someone has designed one for it here (had to dig a bit on Thingiverse): https://www.thingiverse.com/thing:563238

One of those Thingiverse files is the manual for this timer in PDF form. The files which start with FRM01 are the STLs for the case, the other two are for a microswitch mount we can ignore.

physicsmajor
Posts: 94
Joined: Sun May 10, 2020 12:56 pm

Re: How to control a LED panel with a Stackshot Controller

Post by physicsmajor »

Here are a few more FRM01 cases with different mounting options which may be of interest, with varying degrees of exposure of terminals or ability to interact with the four buttons while enclosed.

https://www.thingiverse.com/thing:3373626
https://www.thingiverse.com/thing:2533001
https://www.thingiverse.com/thing:4090509
https://www.thingiverse.com/thing:2525340

And this person rewrote the user manual to be more comprehensible:
https://www.thingiverse.com/thing:703067

Chris S.
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Re: How to control a LED panel with a Stackshot Controller

Post by Chris S. »

This is a link on Amazon to the programmable relay module I used. The price has dropped by a few dollars since I last purchased one. I purchased several and also use them as intervalometers in time lapse and to regulate watering of terrariums.


https://www.amazon.com/UCTRONICS-Progr ... ljaz10cnVl
I ordered this item, and it came in today. If I read its instructions correctly, this particular unit is designed to consume 12V DC for its operation (though it can control a wide variety of A/C and D/C voltage/amp combinations with its relay). For my needs, this is fine. But if someone wants a similar module that consumes 5V DC (as mentioned earlier in the thread), there seem to be many similar offerings, such as this:
https://www.amazon.com/6-30V-Programmab ... 38NH&psc=1

Physicsmajor, I appreciate the links you've added--especially the improved user manual.

--Chris S.

BugEZ
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Location: Loves Park Illinois

Re: How to control a LED panel with a Stackshot Controller

Post by BugEZ »

I mentioned using the hotshoe to trigger my LED light pulse. I made a simple DIY connector to interface with the hot shoe pad. This link describes the connector.

http://www.photomacrography.net/forum/v ... 25&t=44928

Keith
Aloha

physicsmajor
Posts: 94
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Re: How to control a LED panel with a Stackshot Controller

Post by physicsmajor »

Chris S. wrote:
Fri May 13, 2022 11:06 pm
I ordered this item, and it came in today. If I read its instructions correctly, this particular unit is designed to consume 12V DC for its operation (though it can control a wide variety of A/C and D/C voltage/amp combinations with its relay). For my needs, this is fine. But if someone wants a similar module that consumes 5V DC (as mentioned earlier in the thread), there seem to be many similar offerings, such as this:
https://www.amazon.com/6-30V-Programmab ... 38NH&psc=1

Physicsmajor, I appreciate the links you've added--especially the improved user manual.

--Chris S.
Caveat - the FRM01 is a fairly specific board with 18 different modes of operation. I've only ever seen it with this exact board layout and a 4 digit LED. The same blue box type relay is frequently seen on other boards, often a few dollars cheaper, but their control circuitry is often much more basic. The one you link here has 4 modes of operation. Depending on your needs, check the manual/info on triggering carefully.

FRM01 boards with full capability are available elsewhere with buyer's choice of 5V, 12V (like the Amazon listing), and 24V operation. If you can wait for shipping from China, these can be pretty inexpensive, for example: https://www.ebay.com/itm/354051497921

Louis L.
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Joined: Wed Jan 07, 2015 9:11 am
Location: Adelaide

Re: How to control a LED panel with a Stackshot Controller

Post by Louis L. »

thank you all for your inputs. I have been busy with other things and could not reply earlier.
BugEZ wrote:
Wed May 11, 2022 12:04 pm
The camera triggers the pulse via the hotshoe.
This solution is attractive and I didn't think about it. I would like to reduce the number of wires across the setup as much as possible, so I will try to avoid this hotshoe option for now but I might try it if I cannot achieve what I am trying to do another way.

I came across a commercial solution, which I believe would do what I want: the OGGLAB synchro light https://www.mjkzz.de/collections/ogglab ... 0694639861

I usually like DIY solutions, and I have found nearly exact same control module as
BugEZ wrote:
Wed May 11, 2022 12:04 pm
a stand alone programmable module for the LED drive pulse. It runs off of 5V (USB supply works fine). It is triggered by the hot-shoe contacts and switches a relay that drives the LED. This is about a $15 module.

I found it on Aliexpress and I ordered the 12v version to have only one source of power supply, for both the module, the LED ( and everything else). It arrived a few weeks after the order was placed, for a total of 5.90 australian $. Happy life 8)
this is its name on the website: DC 5V 12V 24V 10A Adjustable Time Delay Relay Module 32 Modes LED Digital Timming Trigger Timer Control Switch Pulse Cycle,
Similar modules can be found after typing "Adjustable Time Delay Relay Module 32 Modes"

I had to fiddle a bit the wiring and finally plugged everything as shown on the picture.
LED command with Stackshot.jpg
It does work. But not perfectly yet... The way the camera is plugged to it might be the issue: the camera triggers the relay after being itself triggered... which in turn leads to some aberrant behaviour.

I think I need to find a way to uncouple the two circuits, but I don't know how to achieve this. I have thought about using an optocoupler, but they need to be power fed, while the circuit that triggers the camera is passive.
Unless I did not connect things well? :-k

If anyone has some knowledge or suggestions, I would love to have their input!


Thanks.
Louis Lignereux

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