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Multiple cameras

Posted: Mon May 13, 2013 8:05 pm
by andy_s
Hi Duka, I might have asked some of these questions on the old forum [but can't remember] so apologies if this was already addressed !

http://digicamcontrol.com/manual/multiple-cameras

states:

"The application uses separate threads for every connected camera, so the transfer order is essentially random"

Can you comment on the limitation to the number simultaneous threads [connected / controllable cameras] and what limitation the USB specification might add to the number of cameras that may be simultaneously controlled ? thanks.



Hi, what i know, most camera

Posted: Mon May 13, 2013 9:03 pm
by Duka Istvan
Hi, what i know, most camera number was connected is 20, but the theoretically limit is 127/USB bus, the used PC computing power and memory is directly proportional to connected camera number. There a setting for transfer in Setting->Advanced->Parallel transfer if is checked this may speed up the transfer but after a number of cameras this is unusable. May some  issues with simultaneously trigger cameras may some lag between cameras.

Thanks Duka - yes, that's my

Posted: Mon May 13, 2013 9:59 pm
by andy_s
Thanks Duka - yes, that's my understaning of the USB protocol [and therefore multiple host controllers (in one workstation)] is a workaround to the 127 figure.

Can you comment whether the number of "simultaneous threads" might be adversely affected by multiple host controllers [on one machine] ?

I guess the only way to check this out will be by way of "trial & error".

[I imagine this may also have been requested earlier ?] Do you have any plans to implement a multi-install-workstation solution ? e.g 20 frames / cameras captured to each of 5 workstations and subsequent [automatic] network transfer of all images to a central processing server ?

If the transfer speed not a

Posted: Mon May 13, 2013 10:31 pm
by Duka Istvan
If the transfer speed not a problem you should uncheck the parallel transfer. A another solution record to the card and after that download photos to PC.On "multi-install-workstation solution" i was not planed in near feature but this may change depend on how many user will request it.If you made some experiments please share your experience or any feature requests. 

Multiple Camera Function

Posted: Tue May 14, 2013 5:05 am
by marekglaser
I'm excited about the capabilities of this software, in particular the multiple camera support. I have 36 Nikon D5100's here to test this feature with.

So far I have connected 2 of the cameras and it seems like when I trigger using the "Capture Photos" button in the Multiple Camera Support panel the software is capturing an image on one camera, then moves on to capture with the next camera. I was expecting or hoping that the captures would be simultaneous. As mentioned in the features section of the website - "bullet time" photos - this is only possible if you can fire all the connected cameras at the same time.

Any advice on this Duka?

Also, I really appreciate the "USE AS MASTER" button. It will help when I will need to set exposure settings across all cameras without having to change settings for each and every individual connected camera.


Hi marekglaser - i'd love to

Posted: Tue May 14, 2013 5:44 pm
by andy_s
Hi marekglaser - i'd love to hear what your usb hub / usb workstation host controller configuration is (if it is already in place) ? i'd be even more interested if a single digicamcontrol install can get 36 frames back to the one machine ? btw - the complexity of the usb specification is high. I am not aware of any programatic method [including Duka's] that can circumvent the random variability of trigger timings across USB.

The one I'm looking at is

Posted: Tue May 14, 2013 8:58 pm
by marekglaser
The one I'm looking at is Manhattan Hub(161718) which you can find on Amazon. Haven't got to that point yet though. I'm going to test with a few more cameras today by connecting directly to a PC workstation.

Just completed a test with 5

Posted: Tue May 14, 2013 9:56 pm
by marekglaser
Just completed a test with 5 cameras, no problems encountered, however the way the software is triggering the shutters one after the other means that my test took approximately 6 seconds from pressing the "CAPTURE PHOTOS" button one time until the 5th camera was triggered. Not exactly useful for "bullet time" photography in its current form. Regardless, I may move forward with the USB hub to try to get more cameras connected and see if I can eventually connect all 36 of them.

To be honest the "bullet time

Posted: Wed May 15, 2013 12:04 am
by Duka Istvan
To be honest the "bullet time" was somehow exaggerated anyway it is a significant lag in usb communication, what i can do to improve somehow the simultaneous trigger 

Hi again marekglaser. With

Posted: Wed May 15, 2013 2:06 am
by andy_s
Hi again marekglaser. With DSLR [even if the trigger signal was instantaneously applied to each camera] the first shutter "curtain" to open has some variability [that variability is potentially to several milli-secs]. The only way to accurately [to mSec level] control the simultaneous opening [or specificaaly time delayed opening] of many shutter(s) "1st curtain(s)" is to use hardware [e.g arduino controlled "opto-isolators"] .

My understanding of "digicamcontrol" is that it is a fantastic product - but [if you need "tight" timing] you will need to use it's software characteristics in combination with other "hardware". PS - I am still VERY interested in how many frames you can return to a single workstation ! [thx :-)]