Multi-camera setup project. - page 8 - Creative Uses of CHDK - CHDK Forum

Multi-camera setup project.

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Offline mphx

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Re: Multi-camera setup project.
« Reply #70 on: 17 / July / 2014, 04:14:59 »
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@reyalp

1. Zoom - I had a problem with set_zoom.I am talking with one camera.Throwing values in set_zoom , while being in rec mode , and nothing .Totally nothing.Then i was fooling around in forum and found a thread of waterwingz who was trying to see why his cameras were shutting down after using a "zoom" script .At some point he threw an idea , putting a set_aflock inside his script before the actual zoom commands.And no problems with his cameras.
So an idea popped to issue a set_aflock(1) before set_zoom..and TAAA-DAAA ..lens moved!
And i created another button in the GUI , with exactly what you said.. !mc:cmd('call ... your lua code').Worked like a charm.
Same thing did with focus...Specifically i created 2 buttons with set_aflock/set_zoom/set_focus in each of them.Partner wants two states of zoom/focus..so we can cycle through them with two buttons.

Overall , zoom and focus worked for multiple cameras.Only thing remained now is ISO and shutter speed...i think i will hardcore ISO from the chdk menu in every camera and i think i found the command for shutter speed.

2. Focus

About getting the initial focus distance.No , i dont expect to do it on all cameras at once.I was thinking the process of setting up the cameras and finding what zoom/focus each one should have so they will be targetting and focusing in the center of the rig.
In few words all cameras will be targetting a specific spot.It would be rather stupid to start throwing values at focus or measuring the distance with some tool .
I was thinking since set_aflock(1) , takes an initial focus before hand over the control of focus..i can target the center of the rig and then issue the command.So it will focus there..if i can get back the distance of THAT focus , probably with get_focus , then i can put the same value of focus to all cameras , since they are gonna targetting the same spot.
I could put the value to my new buttons i created with set_aflock/zoom/focus and all cameras focus at the same spot.Minor adjustments may be needed but that would be easy to handle.


Thanks.

Re: Multi-camera setup project.
« Reply #71 on: 17 / July / 2014, 09:32:50 »
Then i was fooling around in forum and found a thread of waterwingz who was trying to see why his cameras were shutting down after using a "zoom" script .At some point he threw an idea , putting a set_aflock inside his script before the actual zoom commands.And no problems with his cameras.
If you are talking about this thread : set_zoom problems in uBASIC & Lua scripts then a number of improvements were found and many others tried. However, I still have at least one camera (SD940), and there are several others like it, that will not zoom reliably so good luck!
« Last Edit: 17 / July / 2014, 10:01:59 by waterwingz »
Ported :   A1200    SD940   G10    Powershot N    G16

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Offline mphx

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Re: Multi-camera setup project.
« Reply #72 on: 17 / July / 2014, 10:58:07 »

If you are talking about this thread : set_zoom problems in uBASIC & Lua scripts then a number of improvements were found and many others tried. However, I still have at least one camera (SD940), and there are several others like it, that will not zoom reliably so good luck!

Well zoom is secondary than focus/iso/shutter speed .I will be happy if i am done with them.Final tests with zoom will be done when we set up the cameras in the rig.

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Offline reyalp

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Re: Multi-camera setup project.
« Reply #73 on: 17 / July / 2014, 17:13:40 »
So an idea popped to issue a set_aflock(1) before set_zoom..and TAAA-DAAA ..lens moved!
OK, this is strange, but as waterwingz says, some cameras have problems with zoom. In a worst case scenario, you should be able to adjust zoom by sending key presses. This is inconvenient on cameras with a large number of zoom steps though.

Note that if you engage af lock using the normal canon firmware (half press + focus mode button, usually) zooming will cancel the AF lock. How this might relate to set_aflock() is not well defined.

Quote
Overall , zoom and focus worked for multiple cameras.Only thing remained now is ISO and shutter speed...i think i will hardcore ISO from the chdk menu in every camera and i think i found the command for shutter speed.
See http://chdk.wikia.com/wiki/CHDK_Scripting_Cross_Reference_Page
You can also look at how testshots sets ISO and TV.

Quote
About getting the initial focus distance.No , i dont expect to do it on all cameras at once.I was thinking the process of setting up the cameras and finding what zoom/focus each one should have so they will be targetting and focusing in the center of the rig.
In few words all cameras will be targetting a specific spot.It would be rather stupid to start throwing values at focus or measuring the distance with some tool .
I was thinking since set_aflock(1) , takes an initial focus before hand over the control of focus..i can target the center of the rig and then issue the command.So it will focus there..if i can get back the distance of THAT focus , probably with get_focus , then i can put the same value of focus to all cameras , since they are gonna targetting the same spot.
I'm still not clear how you expect this procedure to actually work.

Some things to keep in mind
1) All of these cameras have a large depth of field. If you have 64 cameras in a ring with a subject in the center, then just setting the focus to about the center of the ring may well be sufficient.
2) Using different zoom will likely change the effective aperture, so different exposures may be required. The distortion in the images will also be different, which may affect your image processing.
3) If you need unique focus, zoom and exposure values for each camera, your shot set up is going to become quite tedious.

You can operate on individual cameras with multicam, although it isn't very convenient at the moment. To send a command, you can use something like:
Code: [Select]
con 1> !mc.cams[1]:write_msg("call return get_focus()")
And to get the results, you could use something like this mess
Code: [Select]
con 1> !r={} mc:get_single_status(mc.cams[1],'call',r) return r
={
 status={
  status={
   [1]=-1,
  },
  cmd="call",
 },
 done=true,
}
The values of the inner status table are the return values (-1 in this case)

The mc.cams[1] identifies the first cam in arbitrary USB order.

Clearly querying / manipulating single cams is something that should be improved, and should tied in with permanent serialnumber based camera identification. It shouldn't be terribly hard to make mc:cmd etc operate on a subset of available cameras.
Don't forget what the H stands for.


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Offline mphx

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Re: Multi-camera setup project.
« Reply #74 on: 17 / July / 2014, 19:13:22 »
@reyalp

First of all we assume that all cameras will have the same settings of zoom(actually no zoom at all) , focus , iso , shutter speed etc.

So if any of the above is going to be set up , its gonna be for all the cameras.So it will be probably set up through multicam.

1.About focus

The idea is that an object will be in a rather steady spot in the middle of all cameras.So every camera has to focus there.Before any shooting .
Autofocus would probably not work well , because we can't control where the small square in viewfinder will target and focus.
So the plan is to set the focus in a steady distance.How do we find how much is the distance from the center of the rig to the cameras?
a)Take a measure tool and start measuring the distance , convert it to mm and set it with set_focus.
b)I thought to get ONE camera to focus in the object spot and get the value of the distance somehow (with get_focus maybe?) and use that value to set the focus distance to EVERY camera.

Thats what i am describing :)

2.About zoom

Zoom is something that came up to my partner's mind.Thinking that maybe the "object" could be small..like a pet , or a small child..cameras should be able to zoom+focus to them .
So we were thinking to use two modes...two states of zoom+focus.. one for everyday use (probably zero zoom + custom focus set) and another one for that special case i described above (custom zoom + custom focus).
Create 2 buttons with the right values and switch between them according the case.
I don't know beforehand if that second state should be applied to all cameras or to some of them.That remains to be tested on site.
And yes it's strange , zoom to work with the "help" of set_aflock but that's a fact.Without it , set_zoom was..dead!


As far as iso and tv are concerned , since iso will be the same at all times for all cameras , i was thinking to put it in the chdk menu...to all cameras...and then "play" with tv to see what value gives the best result.

All these are theories , and remain to be tested when we will actually set up the cameras (in 1-2 weeks that is).

I will keep your example scripts in mind , in case , specific subnet of cameras should be setup with certain focus/zoom/etc values although i feel the same with what you said..it will be a bit tedious to do so.Lets hope it won't be needed.
« Last Edit: 17 / July / 2014, 19:15:04 by mphx »

Re: Multi-camera setup project.
« Reply #75 on: 17 / July / 2014, 19:45:44 »
As far as iso and tv are concerned , since iso will be the same at all times for all cameras , i was thinking to put it in the chdk menu...to all cameras...and then "play" with tv to see what value gives the best result.
Why not just set the ISO in the Canon menu for each camera?  You only ever need to do it once.
Ported :   A1200    SD940   G10    Powershot N    G16

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Offline reyalp

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Re: Multi-camera setup project.
« Reply #76 on: 17 / July / 2014, 22:59:45 »
a)Take a measure tool and start measuring the distance , convert it to mm and set it with set_focus.
If the object is centered, you can probably just take the radius of the ring, and always use that value. Or if your object is large compared to the ring, subtract it's radius. As I said, the cameras have large depth of field so unless the subject is quite close it doesn't have to be very precise.

That said, you could easily use the code I posted to get focus on one camera and then then set focus on all of them. If you use the GUI may even be able to check focus in the live view.

How big is the ring?
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Zoom is something that came up to my partner's mind.Thinking that maybe the "object" could be small..like a pet , or a small child..cameras should be able to zoom+focus to them .
So all the cameras would have the same zoom, that makes sense.
Don't forget what the H stands for.

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Offline mphx

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Re: Multi-camera setup project.
« Reply #77 on: 18 / July / 2014, 07:38:14 »

Why not just set the ISO in the Canon menu for each camera?  You only ever need to do it once.


That's the plan. :)

Quote
If the object is centered, you can probably just take the radius of the ring, and always use that value. Or if your object is large compared to the ring, subtract it's radius. As I said, the cameras have large depth of field so unless the subject is quite close it doesn't have to be very precise.

That said, you could easily use the code I posted to get focus on one camera and then then set focus on all of them. If you use the GUI may even be able to check focus in the live view.

How big is the ring?

That's a good idea. Calculate the radius of the ring and use it as focus distance.Objects will be mostly humans..so their width would make little difference to the distance.
How big the ring will be ?Hmm i don't know the specifics yet...i assume around 4-5 meters in diameter at maximum.Something like that.


New cameras are being ordered Monday/Tuesday , so i will do some more tests with more cameras , to see how sync will behave :) Although i am running out of power outlets at home ...
« Last Edit: 18 / July / 2014, 07:42:45 by mphx »


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Offline reyalp

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Re: Multi-camera setup project.
« Reply #78 on: 18 / July / 2014, 22:11:15 »
How big the ring will be ?Hmm i don't know the specifics yet...i assume around 4-5 meters in diameter at maximum.Something like that.
With a human sized subject standing ~2 meters from the cameras, I'd expect you can just set the focus to about that distance and never need to change it.
Don't forget what the H stands for.

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Offline mphx

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Re: Multi-camera setup project.
« Reply #79 on: 19 / July / 2014, 05:52:13 »
With a human sized subject standing ~2 meters from the cameras, I'd expect you can just set the focus to about that distance and never need to change it.

Talk to "partner" and the radius will be about 2.30 meters. So yes , what you said it will be the case.

 

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