# Wireless Video Transmission



## gafftaper (Sep 20, 2007)

I've talked in the past about my idea of setting up the night vision camera monitor system for the new theater. Now I'm thinking about taking that system wireless. It'll make the system much easier to move around the black box. And it will allow me to add a second receiver in the green room to have a video monitor back there as well. 

Does anyone have any experience with wireless video transmission? I'm tentatively looking at the Videocomm 5.8 Ghz system. I can get a transmitter and two receivers for about $560. 

Any thoughts?


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## avkid (Sep 20, 2007)

5.8 GHZ is relatively clear.
_
"As the most recently adopted cordless phone frequency, the 5.8 GHz band offers the least interference."_

I would have gone with a more robust and future resistant connector, such as S-Video or go backwards with good old RG6.


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## gafftaper (Sep 20, 2007)

avkid said:


> 5.8 GHZ is relatively clear.
> _
> "As the most recently adopted cordless phone frequency, the 5.8 GHz band offers the least interference."_
> I would have gone with a more robust and future resistant connector, such as S-Video or go backwards with good old RG6.



Interesting point with the connectors. I'll have to see if there are other 5.8 Ghz transmitters with other options for the outputs. It may be a problem as I'm using security system grade equipment, not the good broadcast quality stuff.


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## Van (Sep 20, 2007)

I went with a wired d-link camera for House and Garden. I found that the 320 lines of resolution that most of the wireless cameras output was just not sufficient for clear monitoring of the stage. The frame rate was also a big issue. A lot of cameras will tell you they output 30PFS but that is only at 320x240, and when you get to 640x480 the frame rate drops to 15- 10 FPS which is real jerky. So really check those specs.


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## gafftaper (Sep 20, 2007)

I haven't picked the final camera yet. I'm going back and forth between a "night vision" camera with LED emitters and a "low light" camera and a good dichroic cold mirror on the front of a PAR as my I.R. source. Either way I'm looking for a fairly high resolution camera.


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## museav (Sep 26, 2007)

avkid said:


> I would have gone with a more robust and future resistant connector, such as S-Video or go backwards with good old RG6.


I'm not sure that I understand this comment. What connector are you discussing? This system is apparently only intended to transmit composite video, so I'm actually impressed that is has a BNC connector rather than an RCA. BNC connectors are a professional video connector and about as robust and universally accepted as you will find. Professional component video, RGBHV, SDI and HD-SDI all use BNC connectors so it is probably actually quite future proof in that sense. I personally do not consider S-Video (4 pin mini-DIN) connectors robust or future resitant while RG-6 is a cable, not a connector, although you could terminate RG-6 with the proper BNC connector. 

Based on the untis I've seen and feedback from others, unless you are willing to spend the money for broadcast quality wirleess tranmission systems, I would make sure that you can either demo the unit before purchasing it or return it later.


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## avkid (Sep 26, 2007)

Wow, I really do need new eyeglasses.
It looked like those were all RCA connectors to me.

BNC's are a great professional connector.


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## SHARYNF (Sep 26, 2007)

The issue is that most of the wireless systems only take one of the fields in stead of the two frames, using this as the first part of the compression, and then compress the image. As images get dark the grain level increases, and the problem with this is that grain is random enough that it is difficult to compress, so the compression does not produce a good image.

You could go with an analog transmission system but it is expensive, and they are quite large, there are professional systems but they are very expensive. IMO over a short distance, there is little difference in the quality of the lower level video transmitters, the cheap home units and the more expensive units like you are looking at are all about the same in image quality, it is more distance and flexibility.

It is also not that obvious, but the s video connection makes more of a difference when the signal is RECORDED, THAN WHEN IT IS DISPLAYED. This is an over simplification, but if you look at pro cameras, for transmission, the typical choices was composit OR component of SDI but rarely s video. If you go to any of the shows where the pro broadcast cameras are being displayed and quality is being shown, they either use the composite ( analog coax) or the Sdi link. It does make a big difference on recording .(an interesting side note is that a number of the manufacturers of VCR's now way after the fact have said off the record that the difference in the cost to make a VCR with standard vs S Video is only a few dollars, but they insisted in keeping the price differential high)

Another option is to take the camera, and use a modulator and then use standard cable tv broadcast, and just have multiple jacks around where you can connect your monitor to. If you troll ebay there are a number of Blonder Tongue frequency agile modulators that come up pretty cheap.

Sharyn


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