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Using cameras with video synthesizers
MUFF WIGGLER Forum Index -> Video Synthesis Goto page 1, 2  Next [all]
Author Using cameras with video synthesizers
lizlarsen
A video camera is an important tool for video art -- technologies have evolved significantly throughout the past couple decades, and most people in a digital capturing/editing workflow take for granted things like needing to have multiple synchronized sources in order to mix video together.

I'm curious what cameras everyone likes or recommends, especially in the context of video synthesis or feedback applications.

And, while you can pick up a cheap security NTSC/PAL camera for a few dollars now online -- it is very scarce to see anything in this price range that can accept external genlock signals, which are important in a live setup, if you want to avoid the cost of frame synchronizers for multiple cameras (which defeats the budget-minded point of buying lots of cheap cameras!)

Are there any currently manufactured video cameras in a lower price range still accept some sort of genlock feature? Or possible modifications anyone has attempted?

I have an Ikegami ITC730A studio tube camera with control rack unit, it has genlock input and RGB output, and I really enjoy using it. But throwing it in a backpack for a live gig isn't going to happen! smile I also have a few cheaper security cameras, all of which are okay.
lizlarsen
Another possible subject for discussion is the use of low-cost security system products in general, as they relate to video art applications (standalone DVRs, switchers, etc.)
felixer
i'm using this one:
http://www.reichelt.de/?ACTION=3;ARTICLE=86870;GROUPID=4017;PROVID=251 2
goes into an edirol V4 and an old tv for video feedback. works out nice Trampoline
wondering if my next purchase will be a mfb vd01 (for display of audio waves). or should i wait and get into some eurorack modules if they are availeble hmmm.....
Popski
Awesome thread. THis has been on my mind for a while.
I have a V4 at my disposal here but I've been trying to figure out a way to use an old switcher to output mutliple (8 or more) small cams before bringing the output into the V4. Anybody have experience with this at all?

I use a handful of cheap pinhole cams from Futurelec. They work fine for video feedback, but have no genlock capabilities. (I'm not really doing video synth stuff yet, just making my own clips and messing around with VDMX or Modul8)

I haven't bought the switcher yet. There are tons on ebay. Ideally I'd like a switcher with midi or DMX control. I know that is highly unlikely so I was thinking something manual like this:
http://cgi.ebay.com/Sierra-Video-System-803102-32-Port-Video-Switcher- WORKS-/130460067249?pt=LH_DefaultDomain_0&hash=item1e6006a5b1


Not sure if that would work.. I'm still just testing the waters with live video stuff and I find it somewhat baffling.
lizlarsen
Quote:
trying to figure out a way to use an old switcher to output mutliple (8 or more) small cams


Ideally for clean switching you want sync'ed video sources, and a switcher that switches based on the vertical sync pulse so that you don't end up switching half-way through the frame and causing a glitch.

That unit should work fine for manual switching, but if the video sources aren't sync'ed then you could get a glitch based on the timing differences between the two sources. I'm not sure if the switching unit has something to compensate for that, though. I know some switchers have some sort of time-delay circuitry, like for switching to different security cameras, etc. It may be possible to modify these to have some sort of external clock pulse input... you'd then have a "sequential switch/sequencer" for video kind of a thing.

Some security cameras also can lock to the AC line (60Hz in north america) -- it's not the same as horizontal sync or genlock so I don't know if you'd see some glitching with trying to mix these sources, but switching should work pretty glitch-free in this case.

If having a little frame glitch whenever you switch doesn't matter to you, none of this should matter much.

Quote:
Ideally I'd like a switcher with midi or DMX control.


There will be an upcoming LZX module that can function as a video-bandwidth switcher and controlled with clock signals/logic signals (I'll have to think about MIDI -- but it is doable if you have a MIDI>Gate/CV interface or with pulses out of your DAW). The same as the LZX mixer/fader/keyer modules, it can work just fine all by itself (as a logic-controlled switcher at video bandwidth), but you'll still have issues with the frame glitches if the sources aren't sync'ed.

One effective strategy would be having two TBC/frame synchronizer modules, with one as the active video, and one is the "queued video" to switch to. Since you only have to worry about switching between 2 sources, you only really need 2 TBCs regardless of the number of inputs. You just need a way to arbitrarily assign them to the TBCs, and you'd have to queue up the source before switching to it.
felixer
@popski: the video switcher (and most other functions) in the V4 can be midi controlled. i've got one myself and was wondering if i should get a computer running it. but then it doesn't interface nicely with the audio/cv/modular gear hmmm.....
i'm into the more organic forms, so i quite like this controlled feedback thing ....
lizlarsen
Speaking of cameras and feedback, I'd love to try an experiment with a tiny camera mounted to one of those tiny pico projectors, as kind of a "feedback ray" where the video feedback is related to whatever surface you were pointing the whole assembly at. Has anyone messed with those pico projectors?
johnnywoods
creatorlars wrote:
Speaking of cameras and feedback, I'd love to try an experiment with a tiny camera mounted to one of those tiny pico projectors, as kind of a "feedback ray" where the video feedback is related to whatever surface you were pointing the whole assembly at. Has anyone messed with those pico projectors?


I've actually done exactly that. I have this silly Eyeclops projector which runs off batteries. I have a bunch of footage somewhere. It looks really sweet. The projector has this really nasty plastic lens, and adds a murky purple and green gradient to everything.
lizlarsen
That sounds like great fun! Would love to see some clips from that.
Popski
felixer wrote:
@popski: the video switcher (and most other functions) in the V4 can be midi controlled. i've got one myself and was wondering if i should get a computer running it. but then it doesn't interface nicely with the audio/cv/modular gear hmmm.....
i'm into the more organic forms, so i quite like this controlled feedback thing ....


yeah, the V4 is great, there just aren't enough inputs for what I'm trying to do next. currently: DVD (of super8 footage), Laptop, Cam.
I'm trying to figure out a way to mix lots of onstage cams, like 16 or so, sequenced...
I bought a couple cheapo switchers on hour ago on ebay..
we'll see how it goes.. not out a lot if they are too glitchy or slow

Looks like I'm going to get sucked into another money/time vacuum in the new year.. gotta recover from my M5n / Xmas / MAQ meltdown here
Popski
@lars.. thanks for the info man, you've helped clarify a ton of stuff. (here and in the videos).. I will be eyeballing the modules over the Xmas break
daverj
I've built a fair number of vertical interval switching matrixes over the years for artists, stage shows, and movie studios. I did a 32x16 switcher for a customer a couple of years ago and he used 24 Sentech STC-N63 cameras with it. They are high resolution NTSC board (or cased) cameras that take external sync. But I think they are up around $500 each, not including power supply.

I looked around a few weeks ago and saw a couple color security cameras that take external sync in the range of a couple hundred dollars, without lenses. I haven't tried any of them, so don't know how well they work.

Without TBCs on the switcher inputs, clean switching between cameras requires the cameras all be locked at the vertical interval. To do fading, wipes, and other effects (such as in a synth) requires them to also be locked at the horizontal interval. They need to be subcarrier locked if they are color cameras and being mixed. You can get away without the color lock if they are being decoded to RGB for a system like LZX, or are being recoded for a system like mine (color locking cameras are probably cheaper than using recoders).

Older B&W external sync cameras used HD and VD for the external sync. Newer ones often use composite sync or black burst (black burst is required if locking color).
adamf
I use Sony DV cameras. They're reliable and robust enough. Many of them offer analogue inputs for recording or passing over firewire, which is handy.

I would like to find something genlock-able though and was also hoping for a budget friendly suggestion.

One way I use cameras in a "synthesis" setup is to create lissajous patterns on the oscilloscope with my Euro modules. I'll then point the camera at the scope and process the output video directly from the camera using my digital video effects processors, which I monitor live on a screen. If the result is interesting enough I can record the whole mess on a separate recording device. I sometimes use optical effects filters on my camera lens to distort the patterns before they pass through the camera's image sensor or deliberatly defocus the lens for fuzzy glowing patterns. If the camera has its own built in effects, these can also be used to process the image.
lizlarsen
Quote:
I looked around a few weeks ago and saw a couple color security cameras that take external sync in the range of a couple hundred dollars, without lenses


Those Sentech cameras at $500 seem pretty great! But $200 seems like much more of an ideal price range, if you were to want to invest in 2-3 identical, compact cameras to accompany a portable video synthesizer setup. Let us know if you recall any of the model numbers (I'll try to do some searching around too.)

Quote:
One way I use cameras in a "synthesis" setup is to create lissajous patterns on the oscilloscope with my Euro modules.


That's a great idea, would love to hear more details on your setup for that. I'm going to try to do some similar experiments soon.
snufkin
I use all sorts of toy/home/prosumer cameras for my experiments

including cheap toy ccd cameras a pixelvision and a few cctv tv cameras

my wj-ave sorts out any sync duties when mixing but that does mean I cant do some of the more old school effects having a camera with external sync allows

I did just pick up one of these tho



for Vidicon tube doctor who type feedback MY ASS IS BLEEDING

any chance of a videcon tube module lars? it could have an x/y/z servo controlled tube (voltage controllable ) pointed at a mini crt or small tft (maybe it would be better to tilt the screen

anyway a silly idea hihi
lizlarsen
Re-manufacturing some sort of small vector display/rescanning solution would be fantastic, so many people want that look (including me.) It would be great to have it all enclosed, behind the module. (mini crt xy and rescanning camera enclosed together in a tiny box.) You'd have frontpanel controls for everything, including voltage controlled camera focus/exposure, etc. The camera part isn't that hard.

That's all dreams right now, but something I'll be continually researching.
lizlarsen
But as far as feedback goes, we definitely have a small LCD preview monitor module in development. Because of mobile technology, small LCD displays are being mass produced and are very affordable. I'd like to include the option for a small mounting bracket attachment on the front of this module, for mounting and positioning a small camera in feedback applications.
snufkin
http://www.flickr.com/photos/64683169@N00/4801788275/in/photostream/

check the tiny crt in here !
daverj
A module with a mini CRT, vidicon tube and lens would be really, really deep. hyper

Not to mention all the high voltage and magnetic fields flying around. An external box on the other hand could work.

Quote:
it could have an x/y/z servo controlled tube (voltage controllable ) pointed at a mini crt


If you're going to do that you also want a fourth axis. Rotation. A motorized focus on the lens would be good too.

Those mini CRTs were what was used as the viewfinder for portable cameras and then camcorders from the 1960s through early 90s. Pretty much any camcorder from the 80s will have one. But they were pretty much all black and white.

If you take a close look at the image of Gary Hill's "Inasmuch As It Is Always Already Taking Place" you'll see several small viewfinder monitors.

http://www.djdesign.com/artists/ghstills3.html
snufkin
daverj wrote:
A module with a mini CRT, vidicon tube and lens would be really, really deep. hyper

Not to mention all the high voltage and magnetic fields flying around. An external box on the other hand could work.

Quote:
it could have an x/y/z servo controlled tube (voltage controllable ) pointed at a mini crt


If you're going to do that you also want a fourth axis. Rotation. A motorized focus on the lens would be good too.

Those mini CRTs were what was used as the viewfinder for portable cameras and then camcorders from the 1960s through early 90s. Pretty much any camcorder from the 80s will have one. But they were pretty much all black and white.

If you take a close look at the image of Gary Hill's "Inasmuch As It Is Always Already Taking Place" you'll see several small viewfinder monitors.

http://www.djdesign.com/artists/ghstills3.html


ha so sweet I love Gary Hill's stuff do you think it's a sensible project then??

I had toyed with the idea of building a hall shaped box for an enclosed feedback rig before

I don't think i'm really up to the task tho I'm just a paint by numbers kind of guy when it comes to electronics (not very solid understanding)

I think the major stumbling blocks would be my lack of knowledge of crt drivers and inability to build a diy vidicon camera

and then controlling servo motors from cv Dead Banana

I wonder of anyone has made a hammond tone wheel module where by the cv would control the speed of the motor which would create the tone

any way I digress

I wonder whether the enclosed vidicon/crt box would be wort it in terms of variation in images
daverj
What's "worth it" to any two people are seldom the same.

If you're not highly technical, then take the non-technical approach. Buy a complete monitor and a complete camera and mount them, without motors, and move one of them around manually. Lots of fun, simple to do. I wouldn't worry about using miniature parts. Get a working 4 inch to 9 inch monitor and get a working camera. You can find all sorts of mechanical mounting devices used for machinery to move them relative to each other.

One caution about vidicon cameras: If you mount it facing straight down, be careful about hitting it. Fine particles inside the tube will sometimes fall onto the vidicon surface inside the tube and you'll have a spot in the image, permanently. Plus of course vidicon tubes "burn" images into them. So if a bright point of light hits the surface for a period of time it becomes permanently part of all images. Or even a weaker point of light over a long period of time. This is true even when they are turned off. So never leave a vidicon camera pointed towards a window even when turned off. The next time you use it you'll end up with a faint window in all of your images.
snufkin
daverj wrote:
What's "worth it" to any two people are seldom the same.

If you're not highly technical, then take the non-technical approach. Buy a complete monitor and a complete camera and mount them, without motors, and move one of them around manually. Lots of fun, simple to do. I wouldn't worry about using miniature parts. Get a working 4 inch to 9 inch monitor and get a working camera. You can find all sorts of mechanical mounting devices used for machinery to move them relative to each other.

One caution about vidicon cameras: If you mount it facing straight down, be careful about hitting it. Fine particles inside the tube will sometimes fall onto the vidicon surface inside the tube and you'll have a spot in the image, permanently. Plus of course vidicon tubes "burn" images into them. So if a bright point of light hits the surface for a period of time it becomes permanently part of all images. Or even a weaker point of light over a long period of time. This is true even when they are turned off. So never leave a vidicon camera pointed towards a window even when turned off. The next time you use it you'll end up with a faint window in all of your images.


well my electronics art that bad I built quite a few synth bits just nothing more complex than a standard audio module

fully aware of the vidicon tube burn thing but will take extra care with the directional mounting stuff if I give it a go

thanks for the advice
eth
lizlarsen wrote:
Another possible subject for discussion is the use of low-cost security system products in general, as they relate to video art applications (standalone DVRs, switchers, etc.)


Reviving this thread! I recently got an Alibi DVR for a cheap way to integrate multiple cameras/video sources with my system, with the added perk of rec/playback capabilities. It also has hue, saturation, digital zoom control... tweaked those and got some awesome instant results with video feedback:



Separate question: as opposed to buying a separate power supply, are there problems I might encounter if I used the 12V and ground from my Eurorack power cable to power 4 cheap security cameras? Noise, probably? I haven't measured the actual current draw of each camera yet, but my tiny synth system only uses maybe 10-15% of the 2A my power supply's 12V rail is rated for.
tau_seti
Necrobump!

I've got a vidiot on the way. What sort of camera should I get?
moloque
I'm using back-up car camera. Got to take one without guide lines and option to unreversed it. For closeup (e.g. install on a singing mic) I have an endoscopic camera. Forget the UHD with that but I'm happy with the results (5 cameras for a total of less than 100 euros). Anyway, all cameras are going into some kind of video synth to get colorized, distorted or whatever…. If it’s to go into a vidiot I’d say go cheap and small. It’s easier to setup as well. I put one on a clamp, so I can easily move it around for other point of view.
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