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-   -   Video switcher choices? (https://www.dvinfo.net/forum/open-dv-discussion/51798-video-switcher-choices.html)

Frederic Segard September 26th, 2005 06:53 PM

Video switcher choices?
We’ve been using the Panasonic MX50 video switcher for a while, but it is dying. We are looking for a new video switcher, and I wanted to know what models some of you may recommend, and why.

At first, we though of getting an 8-input switcher, but alas, that is in the realm of the extremely expensive (a.k.a. Grass Valley, Ross, etc..) And the MX70 is too awkward with its shift button to access the other inputs above 4.

Since we work in the DV domain, my thought of using a DV switcher was on my list of important feature to have (i.e. Datavideo SE-800). Although I am worried about the cable distances and the flaky firewire connection to camcorder. If going pure analog : composite or s-video out, to analog mixer, to DV deck… how much of a drop in quality (if any) will I get compared to pure DV? And if there is a noticeable drop in quality, how quantifiable is it?


James Emory September 26th, 2005 07:10 PM

Could you give some examples of what is going wrong with your MX-50? I have one too and want to know some symptoms to look for.

I get great results with 200 ft and up to 300 ft cable runs splitting the Y/C signal at the camera via Y/C>2 BNC, one for Y and one for C, down two seperate true 75 ohm BNC broadcast cables, rejoining the Y/C signal at the truck then passing through a Kramer DA and finally to the switcher. Now, I have noticed a considerable difference in color quality between the Y/C mix and the ISO source tapes from the cameras. In other words, when I load the Y/C mix in the NLE and then load all of the ISO footage for fixing mistakes I can see a considerable difference in color by a direct A/B comparison on the timeline of the camera footage which is native DV and the Y/C footage from the deck mix. In some cases, I have recut an entire project from the ISO tapes using the mix as a guide because the mixe's footage just wasn't as clean or vivid as the ISO footage. So if the fixes/patches were added to the mix you could obviously see the color difference. This problem really baffled me for the first couple of years of doing this until I finally did an A/B comparison and realized the huge difference of color quality between how native DV and Y/C are recorded.

Mark Utley September 27th, 2005 02:00 AM

With Firewire, you might get a bit of a delay if it's a long line. I don't think you can send extra "oomph" through them, so there's probably no way around that. It would get the highest quality, though. If your cameras have BNC outputs, that would be the best option. Assuming they don't, s-video is the next best choice, followed by composite.

James Emory September 27th, 2005 07:06 AM

Firewire repeaters
I have heard of firewire repeaters that are available to maintain the signal through long runs. But, firewire cable is not durable enough for location work. It could never stand up to the abuse that typical production a/v snakes do. Its best application would be for permanent installation in a studio. Even Y/C cable isn't durable enough. That's why I split the signal at the camera and send it down two seperate BNC lines that are protected in a tough PVC jacket. I use BNC to get Y/C quality.

Frederic Segard September 27th, 2005 08:04 PM

My MX50 has been pushed, beaten, dragged, and punched. Its dying condition has, to my knowledge, no bearing on its functionality, or lack thereof. Just physical neglect.

Firewire repeaters aside, from my talks today with several vendors, and with the feedback from the forum; it is clear to me that Firewire cables in the field are a problem awaiting to happen. Unless there are special field cables for Firewire, I guess I can scratch that idea. Anyway, the 4 pin connector on most camcorders would never stand the abuse. I curse the industry for not making robust Firewire connections.

It's too bad that most camcorders to not have component out. So this leaves y/c. It's definitely a good idea splitting the signal on separate coax cables. However, I am a bit worried about James' experience with color degradation.

Are there asynchronous (non-genlocked) video switchers (unlike the MX50) out there that allow you to straight cut from the same bus without getting glitches (or freeze frames)? Meaning, can you just cut from the same row of buttons without switching from the A bus to the B bus, and back to the A bus, so on and so forth, for each cut. This is getting on my nerves. I just want to be able to put one hand on the buttons, and switch when needed without looking at the position the bus light is in when changing row.

James Emory September 27th, 2005 08:22 PM

Native DV and Y/C
I call what you're describing a linear cut, that is, cutting left or right on the same bus. I hate that switching issue too!! It is inherent in all MX-50 switchers though. When I described the color differenc earlier, I probably shouldn't have said it was a huge difference in quality. The Y/C color is just not as rich as the native ISO footage. The color issue with using Y/C and the mix isn't so bad as long as you use dissolves and not cuts between the native ISO source footage from cameras and the mix. As you know, a dissolve blends the color more gradually so it's less noticeable than with an abrupt cut.

Glenn Chan September 27th, 2005 10:11 PM

James: maybe there is a difference in the way things are setup, that's why the signals looks very different?

I would think that a crappy cable might just lead to higher noise, not color shifts. Maybe you can play bars on the cameras and check the bars when you bring them into your editing system.

James Emory September 28th, 2005 04:58 AM

The difference is that firewire is better quality than Y/C. All of my cables are fine and there has never been any noise. At first, I thought it was the length of the cable runs. Then I thought that the cameras, XL-1's, that were probably recording a better image on the ISO tapes than the Panasonic AG-DV2000 deck was for the mix, you know different brands, one is a camera and one is a deck. Finally, what I found after doing a comparison of how video was fed to the deck was that when I sent a video signal from a camera via firewire to the deck it was the same great quality recorded on the deck as the ISO tapes from the camera. So this shows that Y/C is good but not as superior as firewire. The quality of Y/C is good enough that if you saw the program monitor in the truck or the finished product and were never told what signal it was, you would never know it was Y/C. It's only if you were to see a direct back to back (A/B) comparison would you see the difference such as if performing fixes in post by adding native ISO footage to the Y/C mix, as I describe earlier. I will try to pull some stills of the same frame from a Y/C mix and native ISO camera footage and post them side by side on a page so you can see the comparison.

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