CurtPalme.com Home Theater Forum

**kal** · Last edited by kal on Thu Jun 06, 2013 7:09 pm; edited 1 time in total

I've been thinking about 4K UltraHD and how it fits in CRT projectors.

Anyone try 4K (2160p) resolution on their CRT projector? This is 3840 x 2160 pixels.

My guy feeling is that it is simply not going to be something that CRT will be able to handle very well.

Reasons: 2160p/60 is around 136Khz scanrate. While the Marquee 9500LC Ultra, Sony G90 and Barco 909 will be able to lock and display it, I find it very hard to believe that they'll be able to resolve it well (especially the 3840 horizontal pixels).

Anyone have a PC video card that supports this sort of output and tried it on their CRT? (Do PC video cards even support this? I'm out of the loop a far as PCs are concerned). Are there even any 4K PC monitors available to do this to begin with?

The other issue for doing 4K Blu-ray playback or similar is that someone (Moome) would have to invent a 4K HDMI analog converter box or card. This would be an expensive box I think and given that very few CRT projectors can even lock on to such a signal, why would one be invented? I don't even want to think of what DACs/buffers for 4K would cost (assuming they exist at all). Why spend time designing an uber-expensive converter that less than 0.1% of analog owners can use?

Discuss!

Kal

Tim in Phoenix · Joined: 21 Oct 2006 Posts: 4409 Location: Phoenix

Hello

CRT might not define single pixels, but would still have the inky blacks and three-dimensionality that sets it apart from digital displays..........

4K strikes me as overkill for home use, leave it to the theaters and simulation applications.

.

Phoenixed · Joined: 13 Oct 2011 Posts: 514 Location: The mitten

I will try it in a few hours on my G90.

Tim in Phoenix · Joined: 21 Oct 2006 Posts: 4409 Location: Phoenix

**kal** · Posted: Tue Jun 04, 2013 1:29 am Post subject:

Tim: I'd prefer to not turn this into a 1080p vs 4K (or a CRT vs digital) debate as there are enough of those already. Wink

What I'm curious about is how people people feel it can resolve. What sort of resolutions are you doing with simulators? Anything as high as 3840 x 2160 pixels?

Phoenixed: Let me know how you make out.

Kal

Spanky Ham · Joined: 22 Mar 2006 Posts: 5643 Location: Comedy Central

**Curt Palme** · Posted: Tue Jun 04, 2013 1:33 am Post subject:

Guys, this may just be the thread to start this in, as I've had 2 emails already today from last night's email.

I don't follow anything cutting edge at all, since I keep the trailing edge going.

My understanding is that 4K needs 2 HDMI cables? So someone like Moome would have to make a 2 HDMI cable to RGBHV converter in order for it to work? Fill me in, and I'll link this thread to the two customers as well.

About all I can add is that I agree, CRT can probably not properly resolve 4K, but there have always been guys (like Ken Hotte for you old timers) that claimed a resolution way past the sweet spot worked fine on CRT. (BTW, Ken claimed 1080p on a hotrodded ECP projector, which I thought was a bogus claim, but some believed him).

Tim in Phoenix · Joined: 21 Oct 2006 Posts: 4409 Location: Phoenix

Guys

I would expect bandwidth limitations to cap CRT at 1920 H, Mike Parker has done some work on extending this. Limits to bandwidth in the video amps switching the electron gun on and off. As for "watchability", I am in the CRT camp forever.

.

km987654 · Posted: Tue Jun 04, 2013 1:49 am Post subject:

What about interlaced?

**AnalogRocks** · Posted: Tue Jun 04, 2013 2:02 am Post subject:

What about blended?

Spanky Ham · Joined: 22 Mar 2006 Posts: 5643 Location: Comedy Central

Curt,
You should give Ken a call. I am sure his liquid cable is legit. You could spec these for all of your installs. Razz

http://www.teoaudio.com/liquid_cable.php

Phoenixed · Joined: 13 Oct 2011 Posts: 514 Location: The mitten

Ok. Nvidia GTX670 (4k out) to Moome V2 equals black screen. I dont have BNC cables long enough to try although I could try getting some long ones tomorrow.

Spanky Ham · Joined: 22 Mar 2006 Posts: 5643 Location: Comedy Central

I believe V2 only goes to HDMI 1.3, which doesn't support 4k. You can try 2560x1600.

Nashou66 · Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY

Blend can do it or at least close to it, there are some versions of 4k HD I guess that are not the full 3840 x 2160. I am sure there will be 2.4 aspect ratio movies shot in 4k that will not be full 4k which is still 1.78 screen.
So if they want a 2.4 aspect movie it be a 3840x1600. So i figure it be about each PJ doing 1730x1600 for a 2.4 aspect content
across two PJ's if using 4 then it be a piece of cake BW wise. then of course other issues of blending come into play here Wink

Nashou

Phoenixed · Joined: 13 Oct 2011 Posts: 514 Location: The mitten

I will also note this. The new NVIDIA driver mentions UltraHD under its resolution selector.

ElTopo · Joined: 07 Nov 2006 Posts: 1640

You can try 2048 x 1536 @60Hz for Cinemascope.

My Sony CRT Monitor locks that signal tack sharp without problems.

If you have two 9 inchers a blend should be possible.

CasetheCorvetteman · Joined: 09 Nov 2008 Posts: 6326 Location: Australia

ElTopo · Joined: 07 Nov 2006 Posts: 1640

So a blend will end up in: 4096 x 1536 @60Hz feeding 2048 x1536 to each projector.

The TV one's can do that.

gjaky · Joined: 05 Jun 2010 Posts: 2802 Location: Budapest, Hungary

Analog RGB is usually limited at 2048x1536-85Hz, very few device can go beyond that on analog plain. But, isn't the 4K strictly paired with the REC. 2020 color space which is much wider than REC. 709 (currently used)?
REC.2020 vs. REC.709

CasetheCorvetteman · Joined: 09 Nov 2008 Posts: 6326 Location: Australia

How did the 909 and 912 do it's 3200x2560? And how does an NEC XG do 2500x2000? Cause i was always under the impression what Gabór says is correct.