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Set Monitor by Wifi instead?


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#1 Kal Karman

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Posted 05 November 2009 - 11:51 AM

I'd love set monitors to dissapear. Instead, anyone who wants to watch what the camera is shooting can do so by putting their computer onto a specific WIFI channel.

That wifi channel would be set up by some sort of WIFI transmitter attached to the camera's video output.

Does my dream product exist?

Thanks,

Kal

Edited by Kal Karman, 05 November 2009 - 11:52 AM.

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#2 Ryan Thomas

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Posted 05 November 2009 - 12:31 PM

Your dream product does exist to a certain extent. It's a wireless video transmitter. The one I've seen in action is the wevi HD video transmitter. The picture quality is pretty fantastic for all being wireless, and I believe it rents for somewhere around 200/day the last time I checked.
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#3 Tim O'Connor

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Posted 05 November 2009 - 12:32 PM

It is a great idea and will likely catch on when it can be done feasibly and people have good quality screens
at their work stations. However, some people won't and will be screaming orders to adjust the color or
whatever is actually wrong with their screens. Then of course there will be the producer viewing it on a cell
phone who won't appreciate the wide shot on his tiny screen and will be firing directors until he gets one who
does nothing but close-ups.

Used right it'll be a good tool. There certainly is a lot of wireless tech available; I haven't seen it for production
monitors in film situations but it's used in sports a lot so I'm sure that it'll be scaled to fit soon. It may be a while
before WiFi is used because that may not be the ideal way to get a good quality image transmitted wirelessly but
for sure there are times when it would be helpful to monitor a camera that is in a remote position and even on regular
living room sets it would be convenient to not have to be tethered in the conventional ways.
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#4 Adrian Sierkowski

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Posted 05 November 2009 - 12:36 PM

As mentioned the biggest problem with a wifi monitor on a computer screen will be calibration. There's a reason why you tent the video village and spend so much time with color bars on a set. (and let's not even get into the atrocious settings on your standard mac/pc monitor....)
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#5 Kal Karman

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Posted 05 November 2009 - 03:29 PM

Hey guys, thanks for your responses..

about the WE VI system, it's great, but still requires a dedicated receiver. My idea is that everybody's built in WIFI on their computers is the receiver. So the product I want is just a single box that transmits the wifi channel from the camera, and then everyone who wants to see it, would have to install the right software on their laptops and choose my wifi network to view.

As for all the worries about color calibration, strong daylight etc... these are all resolvable and secondary to the main issue of just basically seeing what is being shot! :)

As a director, I would love if there were monitors for styling, make-up, hair, client, agency, producer, actors etc. etc. Let everyone see the shots, play them back, understand etc...

If this could happen, it would take a lot of eyes off my screen, less cables around the set... faster set-ups etc.

You are probably thinking: Yeah, but with everyone watching, then everyone will bug you all the time with their comments!
My answer: let me deal with that, I have my assistants as my buffer, and prefer if everyone can watch.. actually, I think it will reduce comments and increase comprehension. And I'm not always right, I need informed input.


Think about it... I could put a mini hoodman on my iphone and watch the shots from wherever on set I want! What freedom!

Come on... someone develop it please!

Thanks,

Kal
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#6 Kal Karman

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Posted 05 November 2009 - 04:53 PM

last thing to add: it seems that the video surveillance business is ahead of us... check out:

http://www.home-tech...extViewPro.aspx

basically the same idea.. but just need someone to make a transmitter to attach to our RCA out on our cameras..

fingers crossed..
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#7 Phil Rhodes

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Posted 05 November 2009 - 06:21 PM

There are a number of internet video streaming applications which already do this, and could be pressed into service. There are two problems:

- Most of the extant tech has high latency. Careful software engineering could reduce this, though there are minimum thresholds to the latency which certain desirable video compression techniques (such as long GOP) can achieve. This is exactly the same problem that leaves TV newscasters on outside broadcasts nodding stupidly at the camera for three seconds while the compression gear sorts it out.

- The challenge of getting a studio full of non-technical people with disparate computer hardware logged onto a wireless network and correctly set up to receive a video stream is not to be underestimated.

Most irksomely, iphones do not support streaming quicktime.
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#8 Keith Walters

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Posted 06 November 2009 - 05:54 AM

There are a number of internet video streaming applications which already do this, and could be pressed into service. There are two problems:

- Most of the extant tech has high latency. Careful software engineering could reduce this, though there are minimum thresholds to the latency which certain desirable video compression techniques (such as long GOP) can achieve. This is exactly the same problem that leaves TV newscasters on outside broadcasts nodding stupidly at the camera for three seconds while the compression gear sorts it out.

- The challenge of getting a studio full of non-technical people with disparate computer hardware logged onto a wireless network and correctly set up to receive a video stream is not to be underestimated.

Most irksomely, iphones do not support streaming quicktime.
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I can't see how you can possibly get around the latency problem at all, at least to any practical extent. There is always going to be a second or so delay unless you're using DV-type compression, which is essentially creating a 25-slides-per-second JPEG slideshow - and needing at least 50 megabits/second (for standard definition).

Compressing video to a data rate that can be practically transmitted by radio requires the processing of several frames at once. This is particularly the case with .H264 and similar high-compression codecs.

I rather think if this was actually feasible, people would already be doing it, surely.

Edited by Keith Walters, 06 November 2009 - 05:56 AM.

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#9 Phil Rhodes

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Posted 06 November 2009 - 07:52 AM

25-slides-per-second JPEG slideshow - and needing at least 50 megabits/second (for standard definition).


25, theoretically, which is, under ideal and carefully-controlled circumstances, within the theoretical ability of a modern wifi network. You could also use a much lower-bitrate MJPEG stream. Actually making this work at a practical level, though...

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#10 Keith Walters

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Posted 06 November 2009 - 05:16 PM

You could also use a much lower-bitrate MJPEG stream.
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Yes, you could also use composite video and a set of cheap 5GHz video senders (which work surprisingly well by the way).
I work in a huge building with about 400 people in it, and I don't know how many Wi-Fi devices. I have trouble making a reliable contact with a Wi-Fi Internet server only about 20 feet away in an adjoining room.
Our spectrum analyzer just shows a big pulsating "block" at 2.4GHz. I'm continually amazed that anybody can pull anything out of that mess :rolleyes:

Our test lab also has a heavily RF-shielded room, and it's amazing how so many Wi-Fi devices will work in there with the most microscopic signal level, only to be next to useless in the real world. Next to our car park we have a large grassed landscaped "crater" which you would expect to be reasonably RF uncontaminated at least as far as microwaves go, but it's surprising how much Wi-FI stuff still won't work in there. It just goes to show that not all Wi-Fi front ends are equal.
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#11 Phil Rhodes

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Posted 06 November 2009 - 05:34 PM

5GHz


Which work unless you or the camera moves. For the benefit of those who haven't done any RF theory, the higher the frequency, the more it becomes like light (both literally and figuratively), and the more it bounces off things. Any real-world microwave RF system exists in an environment that looks, to it, like a hall of mirrors. Within that hall are innumerable zones of constructive and destructive interference, which is why such systems often appear to be strangely unreliable - try moving your laptop a few inches. The same goes very much for video links, which is why they pop and distort and fizz when you walk around with them, but seem to work OK once you find the sweet spot.

I have three pairs of 2.4GHz video links which I've modified with hirose power and signal connectors and (legal only on the receiver) high-gain antennae and they exhibit these phenomena quite reliably. Other issues include the fact that one of their three selectable channels collides with the spurious emissions of microwave ovens (a good reason to go to 5GHz) and you can't use all three in parallel, as the centre and upper frequencies are frankly too close together and stomp all over each other, even when you (completely illegally) tweak the upper one as far away as the IF synths in the transmitters will go. No, the incredibly expensive ones sold specifically to the film and TV industries are not any better.

Much lower-frequency video links at normal FM TV broadcast frequencies work far better, but anything worth using in that band is usually illegal. Having someone's steadicam sled and someone else's camera and lenses confiscated will put the loss of your $50 video link into perspective.

The only way to make any real headway is to start using yagi or, if you're feeling really adventurous, dish parabolic antennae, and you can do this by pilfering parts from wifi installers' catalogues. Putting an assistant on a yagi antenna aimed carefully at the camera using an optical sight is by far the best investment you can make, increasing both antenna gain and rejection of interference. Producers, needless to say, fail to understand this, and will criticise the flakiness of the link you are using while in the same breath refusing to pay for an antenna aiming person.

The next best thing you can do is use a diversity receiver, which makes up in part for the hall-of-mirrors effect, but these are hugely expensive at microwave frequencies and again nobody is willing to pay what you'd need to charge to make them worth owning.

Basically, there are many good solutions to this but none that anyone will ever pay for.

That said having a triplet of video links does make things very nice and easy on video assist jobs, and using all the channels at once (if you can get away with it) will have the amusing side effect of eating the entire ISM band and preventing wifi or bluetooth devices from working anywhere within a hundred-foot radius.

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#12 Keith Walters

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Posted 06 November 2009 - 07:26 PM

I've actually found the analog 5~Ghz video senders to be quite reliable (I can't remember the exact frequency), certainly better than the 2.4GHz ones at any rate.

Back in the early 90s I was able to get very respectable results with cheap UHF video senders by re-tuning them to 500MHz so they could use the "rubber ducky" antennas supplied with Motorola UHF walkie talkies. There was one brand that uses a Siemens chip specifically designed for that job and it gave amazingly good results for the price. The only problem was that you couldn't use the Motorolas while they were working but most sets maintain "radio silence" during shooting anyway.

Later we moved up to Modulus transmitters with about a 1W output, but they hardly worked any better unless you were out in the open. Indoors, multipath problems would ruin reception long before signal strength became an issue.
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#13 Phil Rhodes

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Posted 06 November 2009 - 07:42 PM

You can of course get one of the exceptionally illegal 500mW microwave amps designed to send wifi across the trackless wastes of Nebraska, which will turn you into a small-scale TV broadcast operation, with the added bonus that you can also cook lunch with it.

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#14 Sasha Riu

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Posted 11 November 2009 - 11:13 AM

As a director, I would love if there were monitors for styling, make-up, hair, client, agency, producer, actors etc. etc. Let everyone see the shots, play them back, understand etc...




That thing already exist!

Its called:

Movie theater!

:)
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