Hello everyone,

I am doing some research for my company. We are a audio post production house amd we are rebuilding our studio c. We have a Sony SRW-5000 that outputs sdi (0 latency version of hdmi) and we would like to find a projector in the under 3k range that can recieve this so we dont have to downconvert the signal for our clients. We have a Eiki LC-X6 on our stage A but this would be total overkill for the studio C room. The size of the room is 22'x20'

We would also like a projector that is rated for atleast 10 hours a day or more and has good bulb life. I'm probably asking a lot for the price tag but its worth doing some research before spending the money on a projector. When in use there are no other light sources aside from dimmed lights and computer monitors. so we don't need to worry about any other light being in the room. Thanks for your time.

To my knowledge there is nothing under $10-20K with an SDI input. You are going to need to ad a converter box to the equation, like one of the little Aja jobs like this:

http://www.aja.com/html/products_converters_HI5.html

$450 or so.

BB

Would this inject latency into the signal chain? We are cutting and mixing audio to the screen so we cant really have much in the way of latency. I guess a better question would be is the hdmi latency at the source or the monitor or both?

If you have latency in the video, assuming you can measure it, can't you just add the same amount to the audio?

oh yes of course thats what we do now. The thing is if the latency is say 500ms or more then things begin to feel unresponsive. If the latency is under 100ms then we can account for it pretty well. I was under the impression that hdmi has a very large latency. Is this not true?

I haven't checked the HDMI specs for any sort of min/max latency requirements. But empirically, regular a/v playback on a PC with the video going out a DVI video card converted to HDMI and the audio going out a totally separate sound card, there isn't a significant amount. My gut sense is that it is in the 10-20msec range, worst case.

Now that SDI/HDMI bridge might introduce some sort of latency, but it can't be too much if you consider the numbers involved. If my math is right, 24p video is about 41msec per frame. So, if the converter were to cause a delay of even 100 msec, that means it would somehow have to buffer over 2 frames worth of data or over 12MB (1920x1080x3bytes =~ 6MB). Chances are it doesn't have 12MB of memory on board so the only place left to put the data is out onto the wire.

Projectors that do have an SDI input are typically doing the same conversion to digital RGB, so if you convert to DVI or HDMI in digital RGB format, it should be no different.

BB

M<aybe you best bet is to check the HDLink boxes from Decklink.com

They have a box that will convert SDI to HDMI/DVI, de-embed audio from ur Deck so u can run less wire to the room, they have LUTs embedded as well and can deal with SD, and almost all flavors of HD as well as PAL signals.

Best part is that it is less than 1K for the top of the line box, leaving u with 2k for a projector.

thats the most affordable way i have found to monitor sdi signals at our studios.

take care

thanks for everyones input. We are going to focus on a sdi>dvi/hdmi converter and a decent projector in the 3k range. Any suggestions on the projector?

Screen size? Lighting control? Viewing distance? Color/contrast priorities?

BB

good questions unlike mine ;p

9.5'x5'ish screen size
Lighting can go down to near zero i.e.no windows in the room.
Viewing distance will be 2 positions 1st 10' and 2nd 19'
Color/Contrast dont need to be perfect but it should look good. hdmi input would be nice and like I said in the first post the bulb must be able to take 10 hours a day (probably closer to 12) and not need replacing every other week.

Thanks!