Sync Multi Cameras - 3d Modeling - page 5 - General Discussion and Assistance - CHDK Forum

Sync Multi Cameras - 3d Modeling

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Re: Sync Multi Cameras - 3d Modeling
« Reply #40 on: 31 / October / 2012, 00:04:00 »
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Here are a couple of answers, more to follow later:

I go into the CHDK "Extra Photo Operations" menu then the "Override Shutter Speed" and the menu is there, but it only show numbers like 1,2,3,4 and I think 1/100 and 1/10000, but not 1/30.  It's odd

I pretty sure mutli restarts fixed it, of course re-install the CCHDK2.CFG file fixes it.  Sorry to not give you exact QA data, but I'm going by memory.

Re: Sync Multi Cameras - 3d Modeling
« Reply #41 on: 31 / October / 2012, 07:35:00 »
I need probably only about 10 msec accuracy.

You should get that result 100% of the time.
Any better synch will be progressively less than 100%.
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if someone else has done the test.

Not that I know of.
My policy these days is if a user fails to carry-out a requested test they get no further assistance of any kind.

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waterwingz - maybe it would be good to make the timeout 2 minutes.

I assume you are not keeping the switch pressed for that amount of time ?
For reasons already stated that is a very bad way of controlling the cameras.

If you are referring to software 'problems' there is no way you need that sort of delay.

Re: Sync Multi Cameras - 3d Modeling
« Reply #42 on: 31 / October / 2012, 10:14:51 »
I assume you are not keeping the switch pressed for that amount of time ?  For reasons already stated that is a very bad way of controlling the cameras.
It's my understanding that he wants to focus & set exposure and then wait for the "perfect" moment to actually take the shot.  However long that is.

Using a "one press" setup means applying USB power and letting the cameras run all the way until they are waiting for sync.  You then hold the "press" until ready to take the shot. Releasing the "press" triggers the sync'd pictures. However, with "one press"  CHDK will timeout in the pressed mode after 20 seconds.   

Using a "two press" setup will work better here - you can hold the first press for as long as necessary.  Releasing the USB power and quickly reapplying and then again removing it will then cause the sync'd pictures to be taken.  It just slightly more complex to actually do but there are no timeouts to worry about while in the "half press" state.

The Ricoh CA-1 also works that way.

« Last Edit: 31 / October / 2012, 10:19:43 by waterwingz »
Ported :   A1200    SD940   G10    Powershot N    G16

Re: Sync Multi Cameras - 3d Modeling
« Reply #43 on: 31 / October / 2012, 10:33:01 »
Using a "two press" setup will work better here

That is what I always use and I suspect most stereo and multi-cam users do as well.


Re: Sync Multi Cameras - 3d Modeling
« Reply #44 on: 31 / October / 2012, 10:52:47 »
That is what I always use and I suspect most stereo and multi-cam users do as well.
In the older CHDK USB remote code (which I understand was ported from early SDM and is thus essentially the same) you didn't actually have a choice as that was the only mode that supported sync.

(unless you had a real CA-1, which the code would "autodetect" based on pulse width timing and then sync on the full press action)


Ported :   A1200    SD940   G10    Powershot N    G16

Re: Sync Multi Cameras - 3d Modeling
« Reply #45 on: 01 / November / 2012, 10:05:52 »
-It's my understanding that he wants to focus & set exposure and then wait for the "perfect" moment to actually take the shot.  However long that is.
Yes, this is what I want to do.

I'm using the "one press".  I did try the "two press" , but I couldn't get it to work.  I will try it again. 

Also, I'm traveling for work in a couple days, so I won't be responding during the 1.5 week trip.

Re: Sync Multi Cameras - 3d Modeling
« Reply #46 on: 01 / November / 2012, 10:07:49 »
I'm using the "one press".  I did try the "two press" , but I couldn't get it to work.  I will try it again. 
You need to do the second press within 1/2 second of releasing the first press. 
Ported :   A1200    SD940   G10    Powershot N    G16

Re: Sync Multi Cameras - 3d Modeling
« Reply #47 on: 24 / October / 2014, 11:34:55 »
Yes, It would be great if I could override the hard coded feature.  There will be many times that the model will be trying to strike a certain poses and it takes longer then 20 seconds.  It would be nice to not have to reset the cameras when this happens.
I rebuilt the old 1.0.0 release and tested the timeout in sync mode.  With that version the timeout existed but rather than being 20 seconds it was only 10 seconds!

We need to think about what to do here.   I guess that I could just eliminate the timeout - not sure if there would be any bad side effects.  I don't really want to add a CHDK menu choice to enable/disable the timeout or set its duration.

I guess this has been answered more recently  ::) do we know yet, or have a better idea, if there are any bad side effects from eliminating the timeout ? thanks.


Re: Sync Multi Cameras - 3d Modeling
« Reply #48 on: 18 / November / 2014, 10:59:43 »
Strange.   Just tested it (for probably the 1000th time) on my SD940.  Works as expected - with or without sync enabled it takes the shot when 5V goes away.  I also enabled a 5 second sync delay to confirm it goes through the sync code.

So I checked the source for the ixus220_elph300hs and it appears the necessary hook for sync shooting is not enabled for that camera.    The hook to wait_until_remote_button_is_released is not implemented in capt_seq.c for any of the firmware versions.  The code hook to disable noise reduction is missing too.

This means you can still try to take pictures with sync disabled but the accuracy of the sync will be suspect.
The above seems it may be relevant to a number of cameras.

In above quote, does this:

"hook to wait_until_remote_button_is_released is not implemented in capt_seq"

in "OnePush/Synch enabled" mean that when +5V is first applied then, as per:

In that mode,  when the USB power is applied,  the code does the equivalent of an immediate "full_press" of the shutter button.  I believe that causes the camera to focus and set exposure right away and then proceed to shoot - where it gets trapped by the "wait_untill_remote_button_released" hook.

In two press mode,  the initial press looks like a "half_press" the camera.  It will focus and set exposure and apparently look for "faces".  Quickly releasing and repressing the remote button triggers the additional "full-press" shot and the "wait_untill_remote_button_released" hook.  Going there with face recognition events queued up seems to be a bad thing if the shooting task "waits".   It's hard to understand why that would be the case as with sync disabled it goes through exactly the same code except for not waiting.
but
(a) because no trap is encountered it is the variability between cameras subsequently getting focus / exposure that causes the loss of "synch enabled" levels of synch between them ?

then:
(b) with a missing  "wait_untill_remote_button_released" hook should both OnePush with either:
Synch enabled
or
Synch disabled
act in exactly the same fashion ?
(c) if the cameras had native Canon Manual Mode / Manual focus, and were in those modes, should the focus/exposure "period" of all cameras be approximately zero and thereby effectively re-instating "synch enabled" levels of synch (even in absence of the hook) ? or is there other "stuff", e.g in "shooting.c", i'm not thinking about yet ?

I'm currently interested to identify a work around to the apparent lack of  "OnePush/Synch enabled" on the SX150IS first reported here http://chdk.setepontos.com/index.php?topic=11667.msg118374#msg118374

Fmi, a further description: http://chdk.setepontos.com/index.php?topic=7127.msg112154#msg112154

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Re: Sync Multi Cameras - 3d Modeling
« Reply #49 on: 18 / November / 2014, 11:31:17 »
Slightly tangential to the current topic, and I suspect you might have spotted this in the press already...

http://www.theguardian.com/science/gallery/2014/nov/17/the-worlds-smallest-sculptures-in-pictures?index=3

... DSLRs, not CHDK so far as I can tell from the pictures.

 

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