Please excuse if my math is not the best, but it seems to me that 240Hz is the first time that you get perfect multiples of 2 for every common US media format that exists. 120Hz is great for 30fps and 60fps video, and even 24fps film. (120/24=5) But then since S3D cinema media is usually the equivalent of 48fps, then doesn't that mean that you have to lose frames for conversion to S3D on a 120Hz set? (120/48=2.5) Wouldn't 120Hz sets (or media players) have to do something similar to how reverse 3:2 pulldown works for 24fps to 30fps, to get 48fps S3D to play well with 60/120fps?

Whats more, I am seeing 1000Hz and 1080Hz for newest sets, when it seems to me that 480Hz, 720Hz, 960Hz, or 1200Hz should be better with everything, as they all are multiples of 240. And as I said before, 240Hz works without doing anything destructive for 24fps, 30fps, 60fps, 60fps, and even a bonus of 120fps video to be shown in S3D.

Sorry if this is a big "DUH" for people on this site. I just haven't heard this discussion before. If I'm wrong about this, please explain. I'm still pretty new here, so be nice.

that depends. for shutterglasses the more the better. for passive polarized 60-75hz is more than enough

No. The TV set and the player would just negotiate a maximum possible frame rate that is divisible by either 24 for passive glasses and 48 for shutter glasses. There is 15 years-old standards suite called Display Data Channel , originated with VGA connector but now supported by DVI, HDMI and DisplayPort, which allows for that kind of communication.
See what happends when you stick to a well-thought license-free industry standard, as opposed to proprietary standards designed in a haphazard fashion using patented technology?

No, the ultimate goal would certainly not be frame-sequential. It would be full resolution, full frame, full color, no glasses 3D. At that point refresh would be irrelevant.

Ah, see that is the piece of tech info I have been missing. This has been throwing me off big time. Does this mean all HDTVs have the capability to adapt to a lower frame rate if they need to? Would any 120Hz HDTV also be able to say, display PAL (25fps) properly at 100Hz? If this is all true, I feel very enlightened... and amazed that the people making the HDTV standard(s) were smart enought to include such a thing, even if it was already developed for PC monitors. Edit: Also, does this mean that 144Hz cinema projectors would adapt perfectly to a 60fps/60fps 3D movie, syncing at 120Hz?


Well, maybe I should rename the title of the thread. "Ultimate" was obviously a poor choice of words. A much better word would be "Ideal". You see, I have read many videophile posts and articles over the years where people have strived for all 24 frames of their films to be seen without reverse 3:2 pulldown conversion. Now that its possible with 96Hz or 120Hz HDTV displays, I just thought it was a downer that the same problem would persist with 3D content. Going by what DmitryKo is saying, that might not be a problem like I thought, because HDTV has an adaptive frame rate in its design, which I did not know. Aparently, thanks to the more open PC industry.

This makes much more sense to me now, but I haven't seen a 60Hz HDTV that could play 24fps without losing frames somehow. I know I am being picky, but not dropping frames is why I started the thread. Edit: I don't know why I thought that 60Hz sets didn't do 24/48. My bad. I guess it would be need to be 60-∞ [FIXT] for passive, with a priority of viewing all frames. 120Hz-∞ should be enough for shutterglasses to handle everything properly, but more is always better. At least, that is how I'm summing this up.

Now I see why 120Hz is so popular, but it now makes me curious why 144Hz is not more common due to the better handling of movies. It should alow for much less flicker in a shutter setup than 96Hz, which is what a 120Hz display would default to.

No. If they only conformed to CEA 861 timings, like many older sets do, arbitrary frame rates wouldn't be possible. You see, DDC and E-EDID standards only provide a mechanism for video mode negotiation, the actual supported modes are defined by the display maker - though some common modes and timing are specified in companion standards like VESA DMT and CEA 861.

However I believe many current digital TV sets can use formulas defined by CVT and CVT-RB (Coordinated Vide Timings, a computer standard by VESA), which means refresh rate can be set more or less arbitrarily within certain limits.

Well, I'm not amazed, because it rather was a 'de facto' standardization that took all too long. It only happened because of convergence of LCD TV and LCD monitor technology. People started using their 1080i HD sets as PC monitors, so they had to start conforming to VESA standards like GTF, CVT and DMT. Without that, HDTV makers would continue to save cents and use cheaper hardware and programming implementations, limited to SDTV and HDTV timings defined in 1990s for underwhelming CRT HDTV sets (you certainly wouldn't want to use those 1080i CRTs as your PC monitor unless you wanted a headache).

Yes. Most current 1080p60 sets do directly support 1080p50 and 1080p24 as well, becase these are the requirements for European HD ready 1080p logo program; it also requires a native resolution mode with no overscan.


Unlike consumer electronic devices, professional equipment is often designed with user-updatable firmware and modular hardware to ease servicing and updates, so I wouldn't be surprised if cinema projectors would be updated if there will be a need to. All in all, I recall cinema theathers are planning to offer stereo translations of sporting events, which I presume would be captured by 60 Hz TV cameras.


think you are answering a question that wasn't asked, but yeah, at that point in the year 2364, we'll have holodeck technology, so refresh would be irrelevant

Thank you for your help DmitryKo. I find this all interesting, as its obviously something I was not able to fully wrap my head around, but now it makes sense.


You know, I have no idea why I thought that. Somehow I kept getting stuck forgetting that its not locked at whatever the maximum is. (60Hz) Thanks for clearing that up. I even veguely remember reading that the 720p60 projector that I own does 24 Hz / 48 Hz sync. Its all coming back now.

I think passive is the way to go. You don't need any more than 60hz, and anything mainstream has to be passive for cost purposes. You can't hand out 300 pairs of active shutter glasses to everyone at the movies. Active will never catch on as a mainstream technology. Hardware requirements for the screen as well as the viewer are too high. I think Nvidia made a mistake by not going with passive devices like IZ3D and Zalman use. I recently bought a new setup for 3D and didn't even consider shutter glasses again.

Actually in Europe the Xpand shutter glasses are used in some theaters and in the US IMAX 3D used to use shutter-glasses prior to around 2005.

I'd be surprised if that ever happened in the states, most of them would end up damaged or stolen. Doesn't make sense to use that technology for so many viewers, when passive is available at a fraction of the cost.

Excuse me for the off-topic, but what kind of glasses do they use in the new digital IMAX theatres nowdays (which are anyways worse than the original 70 mm film ones)? Aren´t they using shutter glasses? Such as these ones:


I went to the only IMAX here in Italy, and it is one of the huge and old ones (likely 5-10 years old, I don´t really know), with 70 mm projector and it uses linear polarized glasses. So I though old 70 mm Imax theaters use polarized glasses, while new digital IMAX ones use shutterglasses...

I went on Avs forums and heard from people that the panasonic and sony tvs had judder when fast motion was used. So it seems like 120hz for plasma and 240hz for lcd isn't enough. Maybe they need to increase to 240 for Plasma and 480hz for lcd

Hmm.. I've never used those glasses before. Not sure when/where those were used but they look recent.

Anyway, the ones I remember from the late 90's early turn of the century were these big bulky headsets:



The ones they use now (at least in NYC probably across the US) are thin over-sized polarized glasses:

Ok, thank you

Koshien I love the Photo of the harry potter people! That girl is so cute! Cyber is correct, here in florida several of the IMAX theaters used to use shutter glasses. I got headaches sometimes with those shutter glasses at IMAX S3D films, but now they all use passive polarized and I don't seem to get headaches anymore. I think the first time I saw Captain EO at disneyworld, many many years ago, they were using passive polarized - can you confirm Cyber?

Anyways I went to see the latest harry potter film at both a stereo3D IMAX theater and at a Dome Imax theater. I hate to dissapoint everyone here, but I liked the IMAX Dome theater presentation of harry potter better. That wide FOV is just a more immersive experience to me in the dome than standard flat screen imax - even with stereo3D. Ideally my local DOME IMAX theater will get stereo3D going and the best of both worlds will be combined. Also, I saw the new Star Trek at that dome IMAX, it seemed to have a little more distortion at the edges than I remember from this new harry potter. Honestly I didn't like this harry potter story as much as others, too predictable and everything rehashed, but visually, at the DOME IMAX, it is one of the best films I have seen at the dome with less distortion than I remember from watching many other films on the dome. Perhaps it was the darker colors of the movie that helped seem to minimize distortion, but I would highly recommend to anyone that has a dome IMAX close to go see Harry Potter and the half blood prince in this format.