HDMI over distance and splitting

[STCM_Tech]

Hey Guys

 

So we up graded our two main projectors before the summer and now the powers that be want to do some live video feeds, its not the feeds that are the issue. At the moment we run our projectors with VGA cables; coming out of the Pc into a splitter/amplifier and then round the room two different ways to our two projectors. Is it going to be a good idea for us to upgrade to running HDMI to get a better picture with the live feeds? I know we would have to convert it to Cat5 to get it over distance.

 

If it is worth us going to HDMI would it work going; HDMI out the PC > Splitter > HDMI to CAT5 > round the room > CAT5 to HDMI > Projector1

,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,> HDMI to CAT5 > round the room > CAT5 to HDMI > Projector2

 

 

I hope that makes sense

[timsabre]

Hey Guys

So we up graded our two main projectors before the summer and now the powers that be want to do some live video feeds, its not the feeds that are the issue. At the moment we run our projectors with VGA cables; coming out of the Pc into a splitter/amplifier and then round the room two different ways to our two projectors. Is it going to be a good idea for us to upgrade to running HDMI to get a better picture with the live feeds? I know we would have to convert it to Cat5 to get it over distance.

 

Unless you have problems with the VGA (such as induction loop interference or earth loop noise bars or something) it's not worth it, you won't see any difference from a normal viewing distance. HDMI over a distance can be a real pain to get working, and also you'll probably lose a few more frames in processing which will delay the live picture.

 

If you're viewing close up on an HD monitor then you'd see a slight improvement.

[David Lee]

Depends what the video feed is really. If it is low quality then you gain nothing, whereas if it is HD 1080p then it is worth it.

 

Where you split you feed depends on location of projector, cable runs and if you want to rely on one feed up to a distribution amplifier that may be in the air and out of reach if problems occur.

 

CAT 5 or CAT 6 isn't the only option - though probably the cheapest. You could convert to HD SDI or go fibre optic.

[timsabre]

Depends what the video feed is really. If it is low quality then you gain nothing, whereas if it is HD 1080p then it is worth it.

 

This is not my experience, we have a live camera setup at church with HD1080i cameras and an HD projector onto a 12ft screen. We feed the projector over HDMI but have a VGA backup cable to it. You really can't see the difference on a camera feed unless you get very close up to the screen. The differences are more obvious when graphics are projected (sharper edges) but even then you have to be unreasonably close to the screen to see it.

[Shez]

What's the native resolution of your projectors?

[STCM_Tech]

The native resolution is 1024 X 768 they are NEC PA500X's

[David Lee]

Ahh, forget it then you won't gain anything at all.

[TonyMitchell]

Depending on the lengths involved and the quality of your cables, you may see an improvement in using 5-wire RGBHV cabling. If your DA just has HD15 outputs, get short HD15 to 5BNC fan outs. Your projectors have 5BNC inputs. Bear in mind the projectors are only XGA, which will likely be the weakest link in the chain.

 

Converting to send over CAT5 & back at the other end may introduce latency issues, which will be particularly relevant, since you mention live feeds. If you do take this route, buy decent conversion kit to minimise latency. We have had good results with the Kramer TP210/220 range.

 

HDMI is (IMO) best avoided for professional applications, because of HDCP issues and limited length of runs.