Video switcher, long cable runs? « Videomaker Community Forums

Evan
Member

I am looking at a mixer for my multicam projects because I think it will really cut down on post production. Anyhow, I am wondering about the cable runs. I plan to use a composite video signal running over a bnc cable (so nothing gets unplugged in the middle of the performance). I am looking at this cable and at most would be running 75-100 feet lengths. Will I encounter significant signal loss?

Posted 2 years ago #
jimcvideo
Member

In theory, you should have no problem at all. I use live switch for many of the events we cover, and I have composite lengths running up to 75 feet. However, personally, if your gear has the ability to do an S-Video out, I would much rather use that. I've discovered that there seems to be a lot less signal loss over S-Video lenghts, and in fact I've commonly run over 200' runs using S-Video cables. The big downside to this is that S-Video cable is also more expensive. So it's a bit of a trade off really.

Posted 2 years ago #
Evan
Member

Well, my gear doesn't really accommodate s-video, so would it help me to convert the signal to s-video and back again on the other end, or is that pointless?

Posted 2 years ago #
XTR-91
Member

I have read before somewhere that an audio adapter (e.g. XLR to 1/8") is more lossy than a long cable, and it is probably the same way with video. You do not want to stream A/V or S-Video over a long cable, as this will cause signal loss to an already very low voltage. Personally, I'd go with the extremely long BNC cable that is designed for long distances, such as Cable TV.

Posted 2 years ago #
jimcvideo
Member

XTR,

You hit off something pretty important, which is that the gauge of your cable affects the quality of your signal.

You're dead right in the sense that if you try to pack a pile of data in a flimsy composite or S-Video cable like the kind connecting your DVD player to your TV, you're going to get signal loss. However, the general rule of thumb is that the beefier your cable is, the longer you can run it with a clean signal. For example, the CVG Premium S-Video cables I use for my switch are almost as big in diamater as the actual S_Video jacks themselves. This is the sort of cable you'd want to use for a long S_Vid run. I've done a 300' run with these guys, and even at that length, there's only the slightest bit of noticable signal loss.

You also hit on a very important point that completely slipped my mind: Coax cable. This stuff is incredible for long composite video runs. Besides the fact that it's dirt cheap thanks to the super mass production of it for cable companies nationwide, It's also an incredibly thick gauge cable with more than enough bandwidth to take long distances. I've seen (amplified) signals shoot more than 1000' over coax. If I were going to go composite, this is the way to go.

Evan,

If you don't have an S-Video line for output, composite cable is the best way to go. In a composite signal, the luminance and color are blended together, which is a problem because they each have their own wire in an S-video cable. To separate them, you would need to buy what's called a comb filter. These things can cost thousands of dollars, and would only be converting you up one notch from about the lowest quality signal (composite) to the second lowest quality signal (s-video). In my book, it wouldn't be worth it.

Instead, I really like XTR's suggestion. At radio shack you can get a couple BNC to coax adapters for a few bucks. If you're a cable subscriber, a lot of cable companies will cut you lengths of coax for free or fairly cheap. That might be the way to go. The added bonus is that coax has enough bandwidth that it can carry an HD video signal across it, something that a standard composite or S-Video cable cannot do.

Posted 2 years ago #
Evan
Member

Thank you, that's what I was thinking. I've had good luck with cable wholesale before, so I'm thinking something like this (see link), I believe it's 22 gauge. I also know they sell coaxial cable at something like 60 bucks for 1000 feet. They also sell BNC ends, how convenient. I do want to ask for anyone who might know, I'm thinking I would want RG59 at 75ohm to match impedance, but I'm not entirely sure on this one.

http://www.cablewholesale.com/specs/bnc-to-bnc-cable/10x3-011hd.htm

Posted 2 years ago #
The shooter
Member

What switcher will you be using?

Posted 2 years ago #
Evan
Member

Well, I'm on a super-tight budget, so I'm considering this one, I understand it is designed for DJ's and people in that kind of field, but I think it would work for me.

http://www.bhphotovideo.com/c/product/561348-REG/VocoPro_KJ_7808RV_KJM_7808_Karaoke_DJ_and.html

Posted 2 years ago #
jimcvideo
Member

Wait a sec before you buy that. What sort of productions are you using this switch for? The reason I ask is because the board you just linked to is perfect for audio-related applications, like VJ work or karaoke, but might not be a perfect for for, say, weddings.

Let us know your application

Posted 2 years ago #
Evan
Member

I do events of various kinds. I know it's not ideal, but I haven't found anything in the sub-500 dollar price range. Let me know if you have suggestions. I'm not even entirely sure I want to go this route. The way I do it now is to import tapes from each camera and cut using the multicam tool in Final Cut. It works fine, other than the fact that post production takes longer and the turn-around time is longer.

Let me know what you think.

Posted 2 years ago #
jimcvideo
Member

As someone who shoots event videos using a switch, I would highly caution you that it may be wise to save for the right equipment than to blow what money you do have on something that won't fully suit your purposes.

I dug all around on the internet looking for a screen shot of that mixer's monitor (keep in mind that you'll need a TV to use as a monitor, so you can see what the other cameras are shooting), and I couldn't find a shot. I would assume it shows you all three inputs, but if not, you could have issues, forcing you to buy a monitor for each camera, thus increasing your cost. Additionally, that thing only has composite outputs. That may be good and all in some cases, but composite outputs are the lowest quality signal there is, and it's going to be greatly inferior to the quality on your MiniDV tapes.

Also, experience is a big thing to consider. I spent four years at the switch console for a live-mixed television program before I went out on my own. Even with that experience, I sometimes miss shots, and find myself editing them back in place in post. It's rare, but it happens. So when you do your first few shoots, assume they're practice, and always have your tapes recording.

In truth, if you're happy doing SD mixing, your best bet may be to save up more and shoot for a nicer mixer. I have a slightly older version of this mixer, which B&H has for $2500 used. It's truly awesome, and worth every penny if you're serious about live mixing. The best part about this board is that it has firewire output, which means that you can bring in your video, mix it, and output it using a high quality DV feed. Additionally, you can bring along a laptop with a DV jack, and record directly to your hard drive, making editing rediculously easy. Well worth the cost.

Now, you could go with the mixer you're looking at, but my question would be how will you capture the video and edit it later? That's fairly important to consider. If you can live with the quality of a composite feed, it will work for now, but really consider saving up a little more. Roland makes some nice gear for about half the price, but the downside is that you have to buy moniors for each feed, which brings you back to about the $2500 of the board I mentioned anyway.

Posted 2 years ago #
EarlC
Moderator

There's a lot of answers, solutions and possible ways to address the post on this thread.

I still use old, tried and true equipment for dual-camera switching at gigs calling for this, or sometimes to save me time in post.

I use 100' Canare RG59 flexible coax cable with BNC and/or BNC to RCA pin plug adapters, a V/A distribution amplifier for runs longer than 100', and an old but still wonderfully functionable Panasonic MX-12 mixer with no appreciable loss in video or audio quality. It is a personal preference to not go longer than 100' without utilizing a DA to keep the signals sweet, but as some have pointed out, longer runs often work.

I have also used the S-Video connections between camera, mixer and end source (editing system, computer hard drive, projector or DVD recorder) for runs of 75' to 100'. There can be some latency issues between the video and audio, using either type of cable, but nothing I cannot deal with provided my audio cable isn't significantly longer than my video cable.

Posted 2 years ago #
The shooter
Member

Switchers are sure expensive. Got an estimate from ross video at 10 000$ :O

Posted 2 years ago #
Evan
Member

What do you think of this one?

http://www.bhphotovideo.com/c/product/26026-REG/JVC_KM3000U_KM_3000U_Component_Special_Effects_Generator.html

Posted 2 years ago #
The shooter
Member

Looks great. Only 500$ ? Wow! what a nice switcher for that price. A panasonic of that level would cost you 5000$

Posted 2 years ago #