Outputs, IMAG, & Format Question

[stevestrike]

We're planning on using a VT4 Live system as the switcher/hub of our IMAG system for church services. Inputs will be cameras, Media Shout video, and internal video playback.

Our specs called for RGBHV output to go to the projectors (NEC GT5000's), but I know the VT4 outputs Y/C or Component. When we asked if we could just use component out of the VT4 to the projectors we were told:

Does it have RGBHV (VGA) Inputs? This is required for the PC.

RGBHV is the highest resolution video signal. I recommend using two scalers to bring the component output up to high res. Scalers are invaluable these days in projection, because they also give control over size and centering.
This was the reason we proposed a scaling switcher, combining the two into one device.

However, it will probably work running component to the projectors.

True? False? I'd appreciate some clarification from anyone here. Should we be investing money in a switching scaler at this point, or is this a waste?

Thanks,
Steve

[Dan Hong]

If you're going to be switching from VT4 to computer sources (song lyrics such as Sunday Plus, or powerpoint for pastor's notes), a switchable scaler is probably a good choice. The scaler will convert the VT4 video signal to a computer signal. Be careful though, a cheap scaler will add latency to the video and cause the service to look like a bad foreign movie.

The reason to convert the signal is this... most projectors now are data projectors, geared for projecting computer sources. They can also project video, but they are internally scaling the video to a computer resolution (most internal scalers are not as efficient as an external unit so they will not be as crisp and also add delay to the signal).

To add a further bit of insanity to this mix, the VT4 now has the capability of taking computer sources (powerpoint for example) and using them as a video source. The signal is probably one of the best scan conversions that I've ever seen, but the program must be run on the VT4 computer, along with the VT4 software. I've yet to be comfortable enough to run a live show and spew powerpoint at the same time.

[stevestrike]

If you're going to be switching from VT4 to computer sources (song lyrics such as Sunday Plus, or powerpoint for pastor's notes), a switchable scaler is probably a good choice.

Let me ask a clarifying question. The only signal being sent to the projectors is directly from the VT4. The powerpoint PC will feed an input on our SX-84.

Do we need a scaler for the VT4 output? I assumed the VT4 would prepare the powerpoint signal to be sent to the projector.

Or are you saying that we need a switching scaler if we were going to run the powerpoint PC directly to the projectors?

Thanks for your help.

[Dan Hong]

If your powerpoint is going through a scan converter and coming into the VT4 as a video signal that's fine. You'll need to check with the projector's manufacturer and see if the projector is meant for data or video. Although all projectors have both vga and video inputs, the internal workings are built to project either data or video and will convert internally to the proper signal. If you're showing video through a data projector, the projector is converting the video to a data (or computer based) signal. This will sometimes add a lot of unwanted delay to live cameras. If your technical people are asking for a RGBHV output from the VT4, I'd assume this is a data projector and depending on the quality (price) of the projector, you may have some delay issues that you may rectify with the addition of a video scaler.

[stevestrike]

I see, so it's the scaling that causes the latency in the switching because of the processing the projector needs to do on the signal? So by adding a scaler, you are bringing the signal into the projector in the format it works with natively, and therefore doesn't require any additional processing. Is that accurate?

Thanks for your help!

[Dan Hong]

Absolutely!!!! Incidentally, how are you getting the signal from the powerpoint into the VT4?

[stevestrike]

Right now, we're using an inexpensive scan converter to go from our powerpoint PC into the VT4.

For an update, we used the VT4 with a camera input for the first time the other night. There is a very noticable delay before the projector shows the VT4 input. Noticable enough that doing IMAG of a live speaker would be VERY distracting. So I guess we'll have to look into the scaler option.

Anyone have a recommendation on a good quality, yet inexpensive video scaler (haha) to take the VT4 output to RGBHV?