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JVC 4K E-shift & UHD?

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3 hours ago, Owen said:

Now when your projector switches from Rec.709 colour space to BT2020 the colour filter needs to drop into the light path and that will do two things. The light output will drop about 40% on your Z1 and the colour calibration settings need to change a lot because the filter blocks parts of the red and green spectrum which changes colour balance very significantly.

 

Wrong yet again! - please stop assuming things.  I have a Sony VPL-VW760ES and there is ZERO  light loss when changing from  BT 709 to BT 2020.   

3 hours ago, Owen said:

I seem to remember I asked you at what distance you viewed your 150" screen from, did you ever reply?

 

I dont have a 150" screen and I don't recall you asking me about seating distance.  

3 hours ago, Owen said:

All too many people get all worked up about 4K "resolution" but put them in front of a projector screen displaying high quality 2K content properly processed and they will not know its not 4K.

A couple of issues here. Firstly , there are those who  process their  4K signals and attest to improved image quality with their projectors.   If you are looking for which format can give the best PQ,  you need to optimise both.  Secondly, your PJ is not ideal to decide such things,  as you must know. It is important for observers to understand this  in the context of your statements.

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Posted (edited)
20 hours ago, Tasso said:

Wrong yet again! - please stop assuming things.  I have a Sony VPL-VW760ES and there is ZERO  light loss when changing from  BT 709 to BT 2020.   

And how is that relevant mate. It doesn't matter what display you have, projector, TV, whatever. There is NO WAY to simply switch off wide gamut when viewing wide gamut encoded video without seriously affecting colour accuracy and SATURATION.

When you where viewing so called "4K" Netflix and originally saw a wide gamut encoded image displayed in Rec.709 mode the colours where inaccurate AND UNDER SATURATED, so when the display worked out what was need and switched to wide gamut mode colour saturation went back to normal rather than deliberately under saturated due to the wrong display gamut being used. For some reason you assumed that what you saw was the difference between normal Rec.709 colour and wide gamut colour when thats not the case at all. It was an apples to banana's comparison that was meaningless.

Rec.709 encoded video must be displayed in Rec.709 and video BT2020 encoded video must be displayed in BT2020. This makes accurate comparisons next to impossible because the content comes from different masters and the display calibration will also be different . 

 

20 hours ago, Tasso said:

I dont have a 150" screen and I don't recall you asking me about seating distance.  

Sorry, I have mixed you up with another forum member. However, I note that you still chose not to divulge what screen size and viewing distance you are using, why is that?

 

20 hours ago, Tasso said:

A couple of issues here. Firstly , there are those who  process their  4K signals and attest to improved image quality with their projectors.   If you are looking for which format can give the best PQ,  you need to optimise both.

True and I do process 4K video, it doesn't need much in the way of sharpening but gamma needs quite a bit of work for projector use.

 

Look, 4K Bluray is without a shadow of a doubt THE best quality movie source the consumer has ever had access to, no question about it, BUT I'm underwhelmed at the magnitude of the improvement over good old 1080 Bluray when its processed well and displayed via a projector.

Keep in mind that I am not resolution obsessed like some so the potential improvement in "resolution" for some movies is not a big deal for me, especially since very few of the movies I want to view are available in 4K or are likely to be. Of those few probably half where never 4K to begin with.

As I said, before the biggest problems I see are due to shortcomings in the original move source that cannot be magically fixed by more pixels, WCG or HDR.

 

20 hours ago, Tasso said:

Secondly, your PJ is not ideal to decide such things,  as you must know. It is important for observers to understand this  in the context of your statements.

That's right I have an E-Shift JVC, however I don't need a "true" 4K projector to work out what level of display resolution is appropriate for my needs. The only times I feel resolution and or sharpness (seperate issues) is lacking is when the video resolution and or sharpness are compromised, as many movies are. A "true" 4K projector can't do anything to correct video source issues.

 

I have no interest in any of the current "true" 4K projectors because of their poor contrast and black performance, which to me is THE most import factor by far and it affects everything I view, not just a handful of 4K Blurays. I wont go near a Sony unless it can be proved that the contrast degradation over time issue is completely resolved, as that is an absolute deal breaker as far as I am concerned.

 

P.S. Sony projectors apply sharpening all the time, even when the user thinks its turned off, so everything you view is being sharpened by RC, like it or not. Its a good trick and sucks most people in.

At least with the JVC's I have owned, sharpening off in the menu is actually off, and thats the way I set it. All scaling and sharpening is done externally for a much better result.

Edited by Owen

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Posted (edited)
2 hours ago, Owen said:

And how is that relevant mate. It doesn't matter what display you have, projector, TV, whatever. There is NO WAY to simply switch off wide gamut when viewing wide gamut encoded video without seriously affecting colour accuracy and SATURATION.

You made it relevant!  You talked about a filter being put in place with massive light loss. There is no filter cutting in, and no light loss.   As for the rest, you have seriously misunderstood what was happening  and how it played out.  I would ordinarily enlighten you but it seems you don't want to know about any situation where BT2020 will look better than BT 709.  Your loss.

 

 

 

2 hours ago, Owen said:

That's right I have an E-Shift JVC, however I don't need a "true" 4K projector to work out what level of display resolution is appropriate for my needs. The only times I feel resolution and or sharpness (seperate issues) is lacking is when the video resolution and or sharpness are compromised, as many movies are.

 

The  pixel size for true 4k is  a fraction of what it is for 2k panels so you will never know the true capability of the format as far as resolution goes.  But I think we have now finally arrived  at the real issue .  That is, you dont want anything better than what you have, and that is fine by me.  

Edited by Tasso

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so if i read this right..........so far we have about 6 pages of 2 people who both insist their right and will never agree with the other.........so at this point.........why bother responding to each other at all?

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Haha yeah haven’t read a good “internets” debate like this for a while!! I don’t know why I persisted through 6 pages but thanks everyone for their input.

 

when I build my new room, I am going to get the latest 4K projector I can (either a Sony or jvc I think, yes I know the jvc’s are “eshift”) ... in my youth I used to like tinkering and up scaling and using things like ffdshow etc ... these days could simply not be bothered.  Will get the projector calibrated by a professional and be done with it!

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3 hours ago, Zinzan said:

Haha yeah haven’t read a good “internets” debate like this for a while!! I don’t know why I persisted through 6 pages but thanks everyone for their input.

 

 

I guess I should have learned something by now  because  whether its  HIFI or AV,  there is always someone who thinks that if they cant get spectacular results from a new format then no-one else can  and the format is nothing short of a world-wide  confidence trick.  I dont' bother  talking to  people dissing DSD anymore but hopefully most   Home Theatre enthusiasts  will be able to exploit the benefits of what 4k UHD has to offer, although we might have to wait a while until the genuine 4k discs outnumber the  fake (upscaled) ones. 

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Hi all, just a query jvc xx9900 can the HDR be bypassed and just get the benefit of higher Rez in sdr?
Probably a silly question

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Posted (edited)
5 hours ago, poppybob said:

Using a 4K disc I meant to say also

 

Your best bet to do that is play the disc with something like an Oppo  or other player that can do effective tone mapping from HDR to SDR type of levels.     

Edited by Tasso

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You have confirmed what I have been thinking about the suitability of HDR with projectors. I have been able to get good results from some 4K discs   but with others I have preferred watching the bluray version, particularly with the "fake 4K"  releases.  Overall I am underwhelmed with HDR on projectors.  I did happen to stream  SDR 4K content with  BT2020 which looked outstanding, but most UHD recordings will need  extensive tone mapping.  
 
Anybody in my family used to be able to turn the system on using a universal remote, insert  a disc and play. Now with HDR, those days are over.
 

What is tone mapping?

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14 hours ago, poppybob said:


What is tone mapping?

 

Firstly , let me say my view has changed significantly from the time I made the comments  included in your quote. This came  after  reading  relevant posts from  SNA members  such as @:) al and @Javs who have successful HDR implementations.  Apart from projector/player settings, the basic requirement to getting HDR right is to ensure that  your screen size and PJ mounting distance are such that it will  result in enough light to make it work.    For example, your JVC will do HDR very well on a  120" 16x9 screen with a PJ mounting distance of 5M - of course there are a myriad of different installations that will work but I use that example as an illustration. The target  is around 30 foot lamberts or higher. 

 

Having established sufficient light  in your setup,  the settings you use for HDR become critical.  This is where players like Oppo  and others that allow for HDR "tone-mapping " can make things easier. 'Tone mapping' refers to the conversion of the dynamic range in an HDR 10 signal ( which usually uses a target of 1000 nits peak brightness )  which is "mapped" ( using predetermined algorithms)  to a target output that will more closely match what you can achieve from your display - eg 100 nits or higher.   You can select the target output on Oppo. Not sure how other brands work.  

 

Calibration - you can have your PJ professionally calibrated for HDR and SDR material. The HDR calibration will usually result in a setup that will  display UHD  HDR images nicely without  intervention from the external player.  Apart from HDR, the BT2020 colour space plays a critical role in the 4K UHD format , and the ability to display a wider colour gamut definitely adds too the experience.  

 

In any event, your PJ is capable of delivering the goods and  if you are looking for  guidance on specific settings etc to achieve an outcome, I suggest posting in a JVC Projector  thread or start a new thread on the topic.    (You don't need the distraction of the earlier discussion in this thread) 

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Thanks Tasso appreciate your valuable feedback and comments.

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On 11/08/2018 at 10:42 PM, poppybob said:

What is tone mapping?

SDR and HDR video have drastically different gamma and colour saturation so the gamma and the colour calibration of the projector must also be VERY different for each video type.

If you try and display HDR video on a display running standard SDR type gamma you get a VERY washed out low contrast picture with highly unsaturated colours, its looks really bad.

So to get a useable picture with HDR video source you MUST re map gamma (tone map) so that on screen gamma is very similar to SDR displayed properly.

 

The SDR standards where designed around CRT TV's which could comfortably achieve about 100nits (30ftl) for peak white, and the colour standard is based on 100nits as well. The 100nit SDR standard was not designed for large screen presentation in a dark room and the result is that the gamma used provides an average picture level that is on the high side for comfort for some viewers when viewed on a big screen in total darkness, although plenty of people like even brighter. 

People often run their projectors at around 50nits with standard gamma as it looks to the eye about the same as 100nits on a much smaller TV in a non dark room. Standard gamma isn't ideal for this but is pretty close.

 

Peak output significantly above 100nits is not happening with a domestic projector unless you run a VERY expensive unit intended for a massive screen on a much smaller one, and since 100nits is by definition SDR there is no such thing as "HDR" using a domestic projector. The HDR standards call for 10 to 40 times more than the 100nit SDR standard (1000 to 4000nit), and even if we are generous and say that 50nits on a projector looks like 100nits on a TV, which it does, we still need a MINIMUM of 500nits to meet the basic HDR standard. If you ran a huge commercial cinema projector in you home theatre you might get close, and if you did the contrast and black level would be bloody terrible.

 

So what do we do? Its simple, we MUST tone map HDR video to SDR or very close. I say very close because the optimal on screen gamma for an image displayed by projector running at 100nits is very similar to one running 50nits, and its just as easy to tone map SDR video to run on a projector at 100nits as it is to tone map HDR for 100nits, and when you do the results can be virtually identical, so close you wont be able to tell.

 

With the JVC, and most projectors, you are going to be relying on the in built HDR preset tone mapping to do most of the work and tweak from there. Different maps can be created on a PC and upload to the projector but not everyone will be into that sort of tweaking. Tone mapping can also be done externally in a player like an OPPO but any preset map is going to be a compromise set buy others that may or may not be ideal.

Unfortunately JVC only provide a limited range of gamma adjustment (unless things have changed recentely), so full custom gamma maps can't be created in the user menu, but should not really be required.

 

I find that HDR titles are rather inconstant compared to normal 1080 Bluray's, I setup a custom gamma map on a PC that looks ideal for one title and the next can require significant changes, which is a pain. I don't feel the need to do that with SDR titles.

 

As for wide gamut colour, there seems to be a lack of understanding as to what "wide gamut" actually is. Wide gamut colours are VERY bright and over the top, think of the most highly saturately crazy cartoon colours you have even seen in a movie displayed on a TV and you are getting close. Obviously real world scenes normally don't contain such colours, especially anything not shot in direct sun light because without high brightness wide gamut colours are not possible. If we take an object that is  a wide gamut colour in the direct sunlight and place it in the shade its no longer a wide gamut colour.

 

High brightness is required for the HDR "effect", which is what it is, and for WCG, unfortunately with projectors we don't have high brightness, just SDR brightness or less with the limits that imposes.

 

There is more to "dynamic range" than just high brightness. An X9xxx JVC projector has more dynamic range than the camera that shot the movie because of its high native contrast and low black level, and in a dark room we don't need super bright for a fantastic image. I find extending the dynamic range in the dark end much more important to image quality then more brightness. With projectors and LCD TV's the brighter the white level the higher the black level, so going brighter has a cost.

 

Don't get caught up is all the 4K, HDR, WCG marketing crap. When you are viewing a Bluray movie, 2k or 4K, on a quality projector non of that matters. The quality of the image will be dictated by calibration and setup more than anything else.

 

 

 

 

 

 

 

 

 

 

 

 

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14 hours ago, poppybob said:

Is this finished now?

You  will always get someone on this forum denying the benefits of new technology. However, given the very successful implementations of UHD and HDR with new projectors by the majority of people who have tackled it properly , the evidence is clear and unrefutable.   There is no point in anyone continually replying to flat-earth types  who preach that new technological advancements are a con because they are not interested in actual proven experiences, just trolling.    This is where the ignore list comes in handy. 

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On 13/08/2018 at 4:01 PM, Owen said:

As for wide gamut colour, there seems to be a lack of understanding as to what "wide gamut" actually is. Wide gamut colours are VERY bright and over the top, think of the most highly saturately crazy cartoon colours you have even seen in a movie displayed on a TV and you are getting close. Obviously real world scenes normally don't contain such colours, especially anything not shot in direct sun light because without high brightness wide gamut colours are not possible. If we take an object that is  a wide gamut colour in the direct sunlight and place it in the shade its no longer a wide gamut colour.

Owen, could you please elaborate on what you mean in the last sentence above?: "If we take an object that is  a wide gamut colour in the direct sunlight and place it in the shade its no longer a wide gamut colour."

 

(For many years I found reds as reproduced on flat screen displays not quite the same as reds I'd see in real life. The displayed reds had a bias towards orange for my vision. This was quite pronounced for my eyes with the standard definition colour standard Rec 601, but became less so less so with the high definition standard Rec 709.  Today's screens I see in showrooms display reds that often come quite close to the reds I perceive in real life.)

 

On 13/08/2018 at 4:01 PM, Owen said:

I find that HDR titles are rather inconstant compared to normal 1080 Bluray's, I setup a custom gamma map on a PC that looks ideal for one title and the next can require significant changes, which is a pain. I don't feel the need to do that with SDR titles.

I would have to agree that HDR 4K titles do seem to vary quite a bit in how they map the dynamic range.

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