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A couple of Multicam doubts and general help

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Re: A couple of Multicam doubts and general help
« Reply #50 on: 28 / November / 2019, 14:19:43 »
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Noob mistake, will never happen again. Will check polarity 20 times before plugging something, I promise.
It's not just a noob mistake. Don't ask how I know.

With no disrespect intended, can I ask if you are sure what polarity is and how you make sure it's connected correctly?



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Ported :   A1200    SD940   G10    Powershot N    G16

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Offline Caefix

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Re: A couple of Multicam doubts and general help
« Reply #51 on: 28 / November / 2019, 14:21:45 »
Less cams- new arrangement.
I use my cams 'offline' only... 8)
I would suggest, You place the cams 'upright', ( "I" not "--".)
So You reduce background and can take the lights on seperate tripods nearer to the center.
(&& I like my Ixus 300 & the S Serie with 1:2.0)
All lifetime is a loan from eternity.

Re: A couple of Multicam doubts and general help
« Reply #52 on: 28 / November / 2019, 14:40:36 »
No disrespect waterwingz! Polarity is the (+) and (-) in any electrical circuit... The current "comes" from the positive and "leaves" from the negative? And the ground is for safekeeping, right? My cheap voltmeter doesn't indicate which cable is which (and they're interchangeable, really cheap stuff) I first checked voltage with a battery, but I believe I mistook the cables when connecting the cameras to the power source. Rookie mistake. Anyway, i can buy new ones, they're dirt cheap here :D

Thanks Caefix for the tips! Cameras are in vertical position, good tip though. I'll check the prices of the models you mentioned. Thx!

Re: A couple of Multicam doubts and general help
« Reply #53 on: 28 / November / 2019, 14:45:47 »
My cheap voltmeter doesn't indicate which cable is which (and they're interchangeable, really cheap stuff)
I have several really cheap voltmeters that I've acquired over the years.  Analog moving coil models and fully digtal model. It is possible to check polarity with even the very worst of them.

What model do you have ? Post a picture here and I may be able to help.
Ported :   A1200    SD940   G10    Powershot N    G16


Re: A couple of Multicam doubts and general help
« Reply #54 on: 29 / November / 2019, 08:39:25 »
I'm off from the city during the weekend, but don't worry once I'm back I'll take care not to screw more cameras again. But thanks for your help! ;)

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Online reyalp

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Re: A couple of Multicam doubts and general help
« Reply #55 on: 30 / November / 2019, 02:22:24 »
And if you say there's a new build coming... I'm not expecting you to do it at all, but just wanted to remind you this ;)
Quote
5- Ideally in the future (completely optional), once the cameras are on their final placement, I think it'd be great to have each camera's focus point saved in an external file, and recall it at the start of every session. But this is just dreamland material for me right now. Better focus on the other stuff
This would definitely be a good feature, I may be able to add support for it in multicam at some point.
In the latest multicam version (r900) I added code to set different shooting options per camera. This doesn't do exactly what you described, but it provides building blocks to do it. The way it works is you can specify any of the shooting options like sv, tv, sd per camera, using an option named camopts, which is a table of id = {options} for each camera. So
Code: [Select]
mc:shoot{camopts={[1]={sd=100},[2]={sd=1000}}}
would set the focus distance of camera 1 to 100mm and camera to 1000. If there were cameras other than 1 or 2, they would just use autofocus or whatever was previously set. The top level values are merged, so if you use
Code: [Select]
mc:shoot{sd=500,camopts={[1]={sd=100},[2]={sd=1000}}}
Any other cameras would use 500. You can also specify different values for different cameras, like
Code: [Select]
mc:shoot{sd=500,svm=768,camopts={[1]={sd=100,tv=96},[2]={sd=1000,av=512}}}
so the default focus distance would be 500, all cameras would use svm 768, and cameras 1 and 2 would have shutter and aperture set, respectively.

Now, typing this all out every time would be annoying, but you can put the table in variable instead: Like
Code: [Select]
my_focus_table={
[1]={sd=100},
[2]={sd=500},
...
[20]={sd=123},
}
(... means you fill in the rest of the values)
and then use it like
Code: [Select]
mc:shoot{tv=123,camopts=my_focus_table}
If you wanted to just change settings for one camera, you could use
Code: [Select]
my_focus_table[3]={sd=456}
If you want to save it to a file, you could use
Code: [Select]
fsutil.writefile_e(util.serialize(my_focus_table,{compact_arrays=false}),'my_focus_table.txt')
and to load it
Code: [Select]
my_focus_table=util.unserialize(fsutil.readfile_e('my_focus_table.txt'))
The format is simple, so you could edit the .txt file in a text editor to adjust the distances if you wanted.

If you wanted to start from the cameras current focus distance from auto focus, you could use something like
Code: [Select]
my_focus_table={}
mc:cmwait('preshoot')
local status,result=mc:cmdwait("call return get_focus()")
for id, res in pairs(result) do
 my_focus_table[id]={sd=res.status.status[1]}
end
Don't forget what the H stands for.

Re: A couple of Multicam doubts and general help
« Reply #56 on: 30 / November / 2019, 08:23:18 »
Wow Reyalp, that's huge!! Thank you so much!! I'm going to need some extra time to play with so many options  :D
AF right now is pretty solid, it nails it down almost everytime. Assuming it's ok, I'd print every focus distance with get_focus and store it, so I can reuse it with camopts. That way I'll be sure to have perfect focus every time. Thanks!!
Code: [Select]
my_focus_table={}
mc:cmwait('preshoot')
local status,result=mc:cmdwait("call return get_focus()")
for id, res in pairs(result) do
 my_focus_table[id]={sd=res.status.status[1]}
end
That's perfect!!!
« Last Edit: 30 / November / 2019, 08:27:00 by ikercito »

Re: A couple of Multicam doubts and general help
« Reply #57 on: 02 / December / 2019, 04:31:04 »
Here goes a pic of the voltmeter, I have polarity sorted out now. All working fine (except that I have two cameras less)


Re: A couple of Multicam doubts and general help
« Reply #58 on: 02 / December / 2019, 06:55:38 »


Here goes a pic of the voltmeter, I have polarity sorted out now.
Nice - the labels on your meter probes are a good idea.

All of my life, red has been positive and black has been negative when doing DC electronics projects. It's kind of an unofficial international standard. Green is always "earth ground" and white undefined but often a positive voltage different than red.

It never occurred to me someone new would not instinctively know that so I was confused about why you were having meter difficulties.

(Of course this knowledge almost resulted in a nasty shock when I first encountered North American mains wiring where to black wire is usually "live" or "hot" )
Ported :   A1200    SD940   G10    Powershot N    G16

Re: A couple of Multicam doubts and general help
« Reply #59 on: 02 / December / 2019, 13:23:34 »

Yeah, it's always been like that for me too! ("Rojo, positivo. Negro, negativo" Here in Spain) But take a look at the meter, cables are interchangeable, and I still can't find any clear indication of + or - to be sure I had them the right way. Anyway, today I checked all the dummies and cabling, and found out where the problem lies... It's terrible and really embarrasing. It's been fixed, it's been a funny facepalm moment. And during the weekend I managed to scour two G10s at a very good price, it's a step up in quality so I'm (somehow) happy I was forced to look for new cameras.


BTW, while checking the dummies I've come to the conclusion I need a different method to make them. If I'm to insert a ground cable, I have not enough precision with my current "grab a piece of plastic and glue a couple of cables at the right distance" method... I've been thinking of using some sort of readymade connector, like a JST or Molex connector with around 3mm spacing between pins (I measured all the batteries, they're all roughly the same) and sand it down to fit inside. I could scavenge an old battery, but it's a bit of a waste and still requires some "precision" soldering (that I'm not skilled enough to do). Do you have any other ideas? Thx!
« Last Edit: 02 / December / 2019, 13:38:37 by ikercito »

 

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