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Continouus shooting with 3D stereo possible?

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Re: Continouus shooting with 3D stereo possible?
« Reply #20 on: 06 / October / 2016, 19:03:07 »
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To use it in continuous mode, all that should be needed is to have the shutter held down, the remote code configured to wait in the hook until it receives a pulse, and something that sends pluses at a rate somewhat lower than the maximum continuous rate.
Well, as usual with CHDK, it's not quite as simple as that.  Who wrote that sync code anyway?   :-[

Holding down the shutter button won't do it.  For the sync mechanism to work,  the flag variable usb_sync_wait_flag must be set - which only happens if the USB remote code sets it or it's set via a CHDK script call to usb_sync_wait().

I'm working on a couple of options to do that. 

The simplest one is based on this and avoids the whole issue of having to enable Canon continuous mode every single f*(*$ing time you restart the camera.  If that's fast enough to achieve the original goal of this thread to take a few shots each time and avoid people "blinking" or simply moving too much then it might be good.

I'm also playing with actually using continuous mode (and the RAW hooks to count shots so that the script can eventually terminate after a user defined # of shots).  But I have not yet verified that the usb_sync_wait_flag work with most ports when shooting in Canon continuous mode.

Stay tuned.


« Last Edit: 06 / October / 2016, 19:21:00 by waterwingz »
Ported :   A1200    SD940   G10    Powershot N    G16

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Re: Continouus shooting with 3D stereo possible?
« Reply #21 on: 06 / October / 2016, 22:17:36 »
Well, as usual with CHDK, it's not quite as simple as that.  Who wrote that sync code anyway?   :-[

Holding down the shutter button won't do it.  For the sync mechanism to work,  the flag variable usb_sync_wait_flag must be set - which only happens if the USB remote code sets it or it's set via a CHDK script call to usb_sync_wait().
Hence my intentionally vague "remote code configured to..." ;)

It seems like you could do with with the help of a relatively simple script.

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I'm working on a couple of options to do that. 

The simplest one is based on this and avoids the whole issue of having to enable Canon continuous mode every single f*(*$ing time you restart the camera.  If that's fast enough to achieve the original goal of this thread to take a few shots each time and avoid people "blinking" or simply moving too much then it might be good.
Most modern cameras remember the continuous setting, but having the hold half, click full method as an option would certainly be nice. In my experience, it's about as fast as continuous on some cameras, and significantly slower on others.

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I'm also playing with actually using continuous mode (and the RAW hooks to count shots so that the script can eventually terminate after a user defined # of shots).  But I have not yet verified that the usb_sync_wait_flag work with most ports when shooting in Canon continuous mode.
I think it will, I haven't had any reports of the shutter hook failing in continuous mode for my scripts (rawopint etc) or the chdkptp commands that use them.Doesn't cover all the models, but does cover a wide range.
Don't forget what the H stands for.

Re: Continouus shooting with 3D stereo possible?
« Reply #22 on: 07 / October / 2016, 05:18:09 »
Hi,

wow - thanks to all for this great discussion - seems not to be very easy to get what I want ;-).
What I can get out of this is:

1. For reasonably good synchronisation (for good quality stereo stills) we need external sync signal from the USB port by either a timer or a microcontroller.

2. Not only the 1st shot needs to get synchronized by the USB port but also the subsequent ones

@waterwingz:
With 'continouus mode' you mean the mode of Canon camera itself?
So if I press the shutter button the cam takes photos as long as I hold the button pressed - right?
Do you think both cams keep in sync for the subsequent shots? If we only trigger the first shot the subsequent shots are timed by each single cam on its own - so the question is if the timers of both cams which drive the subsequent shots run synchronously enough for the subsequent shots.
I would prefer a 'stereo continouus mode' where all shots are synced by the external USB signal.


What about following idea:
Under 'Remote parameters' of CHDK there are 'Control modes' like 'none', 'normal', 'quick', etc.
What about the idea of an additional mode lets call it 'stereo_continouus' which is a mixture of 'normal' and 'quick'.
For the first shot the cam is in 'normal' mode to wait for focus, exposure, etc. and wait until the USB goes down to 0V again to get the first shot. Then the camera should switch to 'quick' mode which just waits for the 5V signal and immediately takes the 2nd shot and with the next pulse the 3rd shot and so on.
The subsequent shots should keep focus and exposure settings from first shot.

May it can be done this way?
« Last Edit: 07 / October / 2016, 05:33:27 by mr.burns »
2 x IXUS 860IS 100c
2 x Powershot S110 103a

Re: Continouus shooting with 3D stereo possible?
« Reply #23 on: 07 / October / 2016, 10:15:12 »
What I can get out of this is:
1. For reasonably good synchronisation (for good quality stereo stills) we need external sync signal from the USB port by either a timer or a microcontroller.
2. Not only the 1st shot needs to get synchronized by the USB port but also the subsequent ones
Correct.

Quote
With 'continouus mode' you mean the mode of Canon camera itself?
So if I press the shutter button the cam takes photos as long as I hold the button pressed - right?
Correct.

Quote
Do you think both cams keep in sync for the subsequent shots? If we only trigger the first shot the subsequent shots are timed by each single cam on its own - so the question is if the timers of both cams which drive the subsequent shots run synchronously enough for the subsequent shots.
I do not believe they will stay sync'd on their own.   This conclusion is also supported by Kasius Klej's test.

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I would prefer a 'stereo continouus mode' where all shots are synced by the external USB signal.
That's what I'm working on too.

Quote
What about following idea:
Under 'Remote parameters' of CHDK there are 'Control modes' like 'none', 'normal', 'quick', etc.
What about the idea of an additional mode lets call it 'stereo_continouus' which is a mixture of 'normal' and 'quick'.
For the first shot the cam is in 'normal' mode to wait for focus, exposure, etc. and wait until the USB goes down to 0V again to get the first shot. Then the camera should switch to 'quick' mode which just waits for the 5V signal and immediately takes the 2nd shot and with the next pulse the 3rd shot and so on.
The subsequent shots should keep focus and exposure settings from first shot.
May it can be done this way?
I thought about adding a mode like that.  But you can also do the same thing with just a script so I thought I'd get that working first.

There is one other refinement on your proposal I'd add - the USB sync mechanism would be enabled.  In that mode,  the script holds down the shutter button and allows the timer/ucontroller to control the rate of continuous firing directly.  Essentially, each shot gets held until the USB signal goes from 5V to 0V.  As both cameras will see that transition at the same time, and they are being held via the sync mechanism at a point right before the shutter opens, they will be in the best sync possible.  The only tricky bit is that the pulse rate needs to be slightly longer that the time to take each shot in continuous mode.   Should be possible to adjust that with a little trial and error.
Ported :   A1200    SD940   G10    Powershot N    G16


Re: Continouus shooting with 3D stereo possible?
« Reply #24 on: 07 / October / 2016, 22:50:04 »
@mr.burns  :

Okay - I've attached two tested scripts that will work with a USB remote connected to two cameras to achieve "precision sync" while shooting continuously.

They both setup the camera & CHDK as required so you don't need anything set in the CHDK USB Remote Menu.  And they both assume that you will toggle the USB remote +5V signal to achieve sync between two cameras.  As this is "open loop" control,  the first pulse needs to be long enough to get focus & exposure - maybe one seconds?  Then just go to 0V for 50 mSec, then back to 5V for 200 mSec and repeat that sequence ( 0v/50mSec, 5V/200mSec ) for the desired number of shots.  You will have to discover by trial&error how fast either script can shoot and adjust the USB external signal to suit.  Sorry.

The scripts have user paramters to allow you to select the number of shots to take.

cShoot1.lua :  for shooting with the camera in Canon Continuous mode.  One nasty thing about Canon continuous mode is that you have to re-enable it every single time you go into shooting mode.  That got to be a huge PITA so I added some key click code to set my G10 into continuous mode when the script starts.  You'll have to hack that code to suit how your cameras enables Canon continuous mode.  Nasty but there is currently no way to set the camera drive mode from a script.

cShoot2.lua :  does not use Canon Continuous mode - simply shoots as fast as possible by holding down the "half press" and toggling "full press", thus avoiding refocus and exposure setting between shots.  It will effectively delay each shot until the USB remote signal goes from +5v to 0v so you can sync two cameras.

I probably should add logging to the code so that I can see what's happening if you have problems.  But it's late now - I'll cross that bridge if you actually use the scripts and have problems.



« Last Edit: 08 / October / 2016, 00:46:40 by waterwingz »
Ported :   A1200    SD940   G10    Powershot N    G16

Re: Continouus shooting with 3D stereo possible?
« Reply #25 on: 10 / October / 2016, 04:53:17 »
Hi waterwingz,

thanks - thats really great!
Currently I am on vacation until 22nd Oct. (we Germans need to go to Mallorca ;-)).
I only have my IXUS860 pair with me (which is hardwired and with my customized SDM) so I can test the scripts with my S110s if I am back.


Thanks so far...
2 x IXUS 860IS 100c
2 x Powershot S110 103a

Re: Continouus shooting with 3D stereo possible?
« Reply #26 on: 31 / October / 2016, 10:39:40 »
Hi waterwingz,


just to let you know, I am back from vacation but could not test your scripts up to now.
The reason is I am very busy in my job and I got a new CNC machine for my hobby which I need to make running first...


I will let you know when I can test your scripts...



2 x IXUS 860IS 100c
2 x Powershot S110 103a

 

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