Cognisys controller - longer exposures

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Kuky
Posts: 3
Joined: Sun Dec 18, 2022 7:47 am

Cognisys controller - longer exposures

Post by Kuky »

Hello,

For years I used my Cognisys controller taking many thousands of shots. I thought I knew how to use it. This week I found out I have no clue.

All the shots I have taken these years with Cognisys I used flash. That never posed a problem as shutter time was 1/125 (on GFX 100S) or 1/200 on Sony A7 so shutter time was faster than Tpulse (500ms).
So by the time the motor was running to advance to next step the exposure was over on the camera.

This week I tried to work with continuous light, hence I needed to use longer exposures, sometimes around 3 to 5 seconds. To my surprise I found out that there is no way to tell the Cognisys controller how much time to wait for the camera to finish exposure when you are doing one shot/step.

From my understanding reading the manual for firmware 1.0.06 (Manual version 1.5) Tpulse is not to be used to pause the controller while camera is doing a long exposure. Manual says Tpulse should be long enough for your camera to respond and begin taking an exposure.
Also Toff works only if #pics > 1 which is not my case.
I understand there is a trick where you set #pics=2 in case you have a camera with a mirror so you can do mirror lock-up in which case Toff could come in handy to stop the motor while taking the exposure. But my camera don't have mirrors.

Next step I upgraded firmware from 1.0.06 to 1.0.09. To my surprise Cognisys never updated the manual for the new configuration settings which appeared in 1.0.09. I made a table comparing settings (attached). There are new config settings - T1 On, T1 Off, T2+On, T2+Off, I/O Mode which are not explained anywhere, not even in the release notes for firmware 1.0.09.

Can somebody please, please enlighten me how to make Congisys wait for a mirrorles camera to finish exposure and then advance to next position (using last firmware 1.0.09)
Also where are this new settings explained?

Thank you very much,
Cristian
Firmware Config Comparison.jpg

rjlittlefield
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Joined: Tue Aug 01, 2006 8:34 am
Location: Richland, Washington State, USA
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Re: Cognisys controller - longer exposures

Post by rjlittlefield »

Kuky wrote:
Mon Feb 06, 2023 4:00 am
There are new config settings - T1 On, T1 Off, T2+On, T2+Off, I/O Mode which are not explained anywhere, not even in the release notes for firmware 1.0.09.

Can somebody please, please enlighten me how to make Congisys wait for a mirrorles camera to finish exposure and then advance to next position (using last firmware 1.0.09)
Also where are this new settings explained?
I have no idea where the new settings are explained, if anywhere, .

Experimentally, T1 OFF seems to do what you want: sets the delay between shutter pulse and motor movement.

I have vague memories that in earlier versions of the firmware, and despite what the manual said, the OFF time actually controlled the time after each pulse, even when only one pulse per step was used. When I wrote the controller in Zerene Stacker, I provided separate settings for time between pulses and time after last pulse. If pulses > 2 then ZS uses the settings as between, ... , between, last, just because that seemed intuitive. In playing with the Cognisys controller just now, I see that it provides separate times but they behave differently: with 4 pulses I saw delays of T1, T2, T2, T2. I have never used more than 2 pulses per step, and offhand I cannot think of use cases in which one or the other sequence would be preferred.

I suggest to play with your controller and see what you find. An email to support@cognisys-inc.com should get you a definitive answer. Please let us know what you learn.

--Rik

Kuky
Posts: 3
Joined: Sun Dec 18, 2022 7:47 am

Re: Cognisys controller - longer exposures

Post by Kuky »

Hi,

Thank you very much for your answer. I contacted Cognisys support and they were very fast and helpful. It is a bit complicated so I will quote from their answer in case anyone has the same problems:
The newest firmware gives the user control over the timing for the 1st
and 2nd pulse that StackShot generates allowing them to be different
lengths if needed. T1 On is the old Tpulse. T1 Off is the old Toff.
Use T1 Off when you want to StackShot to wait for a long exposure. T2
On and Off do the same thing for the second pulse (generally used for
mirror lockup). If you think about the on and off times as button
presses and pauses, the on time is the amount of time the button is held
down and the off time is the pause between two button presses or the
first button press and a move
If the number of pics is 1, only T1 Off is active. The T2 parameters become active when the number of pics >=2. This assumes the ToFinal is set to yes. ToFinal is the parameter that enables T1 Off if the number of pics is set to 1.
Disable the T2 parameters by setting the number of pics to 1 - after that the number in T2 On and T2 Off do not matter.

I/O mode is used if you want to change the use of the Shutter Output (Labeled "Trigger" on the controller). It will let you configure this port as an input to move the motor on a trigger.

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