No judder at 48hz – what a difference! - Page 2  

It's pretty simple. Film is 24fps although the DCI spec does allow for 48fps in an all digital system. Celloiud film will always be at 24fps except for specialized applications, IMAX, time analysis, etc.

Live and standard definition television is 50 or 60hz based depending in the country's electrical system though that tie between frame rate and electrical frequency is long since obsolete*.

It's just the standards and there is far too much hardware in place to ever chnge it otherwise. It would be like making all new rail road track spacing a foot wider.

*Once color TV came about the 60hz vertical rate was no longer able to be locked to the power line as it became 59.94hz due to some complex math problems in encoding the color information to be compatable with Black and White. Even before that power line locking was rarely used as it was too instable.

60hz won't go away because there's quite a bit of content still being shot in 60Hz (e.g., Leno, conan, etc.).

Will i get flicker on my xg crt projector?

If 50p [pal progressive] doesn,t give noticable flicker will i be ok with 48p from a lumagen hdp? 72p is too high for an 8 inch crt.

I have the Pearl and the Lumagen HDP. I have a HTPC and an XBox 360 (with HD DVD) connected to the Lumagen. Do I need to make changes to my sources (change PC refresh rate to 24Hz in order to see the benefits or will the lumagen translate the 30Hz signal back to 24Hz without judder? Sorry, but this confuses me. I always thought that the Lumagen would process the video and resolve any judder before it gets to the projector.

Can the Xbox 360 play at 24hz?

Shan

your HTPC should remain at 60HZ (that's usually the ideal for a PC).

24hz is only relevant for HD DVD stuff, but I doubt the XBOX can be converted to play at 48hz or 24hz... 24fps is a Sony innovation, so it's more for BD than for HDDVD.

I have a Momitsu V880N that lets me setup custom DVI output resolutions. I set it up for 1080/24i but I get major studdering with the picture (un-watchable)

The Sony "info" shows 1080/24p so I guess it takes the interlace and converts to progressive. I thought it would change it to 96?

Any thoughts on why it does not work?

Here are the custom settings on the V880:

HorizFreq 27000 VertFreq 2400
VideoWidth 1920 VideoHeight 1080
HSyncTotal 2058 PreHSync 16
HSyncActive 64 PostHSync 58
VSyncTotal 1125 PreVSync 0
VSyncActive 6 PostVSync 39
HSyncPol 0 VSyncPol 0

If anyone can point me in the right direction on setting the Momitsu for optimal use with the Pearl and how to get it to do the vertical stretch for my UH380 Panamorph lens I would be ever in your debt. I would like to use the V880 for all my SD DVD material and I have a Snazio HD player for my Hi-Def material.

Try setting it up for 1080i at 23.976 (24/1.001) frames/sec, which is equivalent to 47.952 Hz (fields/sec).

For more details, go to my Custom DVI Settings web page.
The Info menu is showing the format of the incoming signal, or at least what the Sony thinks it is. The Sony might be converting it to 96Hz internally in order to drive the panels, but the Info menu does not show what is happening internally.
The Pearl can do the vertical stretch for 480i/480p signals (by selecting the Pearl's "Wide Zoom" mode), but not for 720p/1080i signals. For 720p/1080i, you could do the vertical stretch with a stand-alone video processor.

Thanks for the reply Erik.

I did try using your web form (have it booked mark from way back) and also another HTML based one (they both give different settings for some reason?) and still have no luck?

Also Alan shows the V880 as being able to do the vertical stretch internally but I can not figure it out? Here is the link: Second to the last posting:

http://www.avsforum.com/avs-vb/showthread.php?t=537491

I have a Pearl and a V880, which is similar to the V880N, so I might try it myself.
Alan left out the part where he explains how. :)

Cool, let me know how it works out for you. I am going to try a few more setting to see if I can get it to work.

I am sure that I got it to do the stretch once before when I had the projector sitting on a table with the old screen. I must be missing a step. There is a place to set the DVD display device in setup for 16x9 or 4x3 letter box or 4x3 pan and scan. There is also a place to set the zoom mode on the first page in setup for the same as listed above plus Actual size, full screen and one other I cant think of.

Hey Mark, good luck with everything... Tried to call just now. Stuck at work till 9:00 p.m.

I use A1 -> LumagenHDP -> Marquee M8000 at 108" (diag) screen, with Lumagen set-up for deinterlacing mode: film, and output 1080p/48, and to me it looks amazingly film-like. You do see slight flicker with large light/white areas, just like in theaters, but it doesn't bother me at all. Funny, because for CRT computer monitors even 72 Hz refresh drive me crazy, at least sometimes... Go figure...

Kris