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post #31 of 845
Quote:
Originally Posted by KenLand
Ok, we're in agreement. Every value other than the two extremes should be in the neighborhood of reality.
We are in some agreement, but I consider blackouts to be reality and raising the light level to purposely make blackouts impossible to be cutting off part of reality.
Quote:
Originally Posted by KenLand
My jury is still out on whether you want such a large gap between 17 and 16.

If 235 is 12 fL then 17 is .004 fL and 16 is .00006 fL. (3K:1 and 200K:1)
Yep. I had a mistake in mine. I used 10 ftL for white and should have had .00005 instead of .0001 for the 200k:1 case.
Quote:
Originally Posted by KenLand
I'm not sure how that would look but its has to be better than crushing your blacks by anchoring your gamma curve at .00006 fL.
You keep saying that this will crush your blacks. Why? If you are talking about having a gamma that comes out very slow then of course you can crush your blacks, but this is a different discussion than where the black point should be. REC.709 calls for an absolute black level that is darker than your 200k:1 level (since it calls for no light) and video 17 to be about 1k:1 from video 235. Do you think matching that would crush your blacks? As I pretty much said before, raising your black level is going to hurt your shadow detail if your other points are kept constant because of the just-noticable-difference factor.
Quote:
Originally Posted by KenLand
No one said that the camera's minimum light sensitivity was its black level. Only that you don't want to waste too many levels between this and black, because the camera has recorded no, none, nada, zilch information at those levels.
The original discussion I was in wasn't about how many levels to give between black and where the camera was sensitive enough to pick up detail, but about where the ideal black level should be given that your original statement was:
Quote:
Originally Posted by KenLand
I think it would be a useful exercise to determine the minimum light sensitivity of modern HD cameras and use that as a practical goal for projector black level. It's not going to be zero light no matter what the spec says.
At this point what do you think the goal for projector absolute black level should be? I think no light (or at least the perception of no light) and haven't seen anything that disputes that.

--Darin
post #32 of 845
Quote:
Originally Posted by dokworm
No, the source is not 8 bit, that is the whole point of one of these displays, they are for people who need to use HDR imagery.

Nothing to stop you talking to them Kenland, their number is on their website.
With a greater than 8bit display, the number of levels available are so huge, that the problem of the number of steps wasted between absolute black and the cameras lowest light register becomes a non-issue. There are plenty of increments left over in a 16bit per channel system :)
Do you know how they can get more than 8 bit data into the display? I see DVI, but that is limited to 8 bit.

--Darin
post #33 of 845
The idea behind crushing blacks is very simple: To have a PERFECT black level, that is, no light output AT ALL, the very next displayable step in black level will certainly be too dim to be seen.

To get a fully visible dark grey scale, you HAVE to settle for a very slight elevation of the total black level. And this is quite acceptable, if you try it.

I'm finicky about black levels, myself, but have found that I can accept a slightly elevated black level in favor of dark grey scale performance more easily than I accept a dead black
black level but at the cost of deepest grey scale resolution. It's more important to me
that I see all that is there in the picture.

CJ
post #34 of 845
Quote:
Originally Posted by cmjohnson
The idea behind crushing blacks is very simple: To have a PERFECT black level, that is, no light output AT ALL, the very next displayable step in black level will certainly be too dim to be seen.

To get a fully visible dark grey scale, you HAVE to settle for a very slight elevation of the total black level. And this is quite acceptable, if you try it.
I am talking about the ideal display, not limitations of CRTs. There is no reason that having the absolute black level at zero means that the next level up will be too dim to be seen other than with CRTs because of the way they normally come out of black when you make them blackout. We've discussed this quite a bit in the past and tse and others are working on circuits that will allow the absolute black level to be no light, while still having the next levels up be reasonable for shadow detail. Even the standards with linear tails above black have the lowest point at no light.

And the ideal may be to have a very slightly elevated black level in mixed scenes, but we already have that with ANSI CR limitations and with the ability to dither between video 16 and video 17, which I addressed earlier. But in my view ideal will never be something that can't reproduce what I see (or don't see) when I walk into a room, closet, or bathroom in my house and have no visible light. If a display can't reproduce that then there is room for improvement.

--Darin
post #35 of 845
But to get the full benefit of that, you'd need to be in a viewing room that is otherwise COMPLETELY dark. No light AT ALL except from the projected image. ANY other light in the
room is going to result in your ultimate black level being slightly washed out.

I'm not sure that that's even a good idea, to try for an utterly dark viewing room.

Also, consider this: The lower limit of how little light you can perceive may be different than
what I can, for physiological reasons. As we get older, the lenses in our eyes lose a bit of their transmissivity, which is a prime cause of night blindness. And then there's the
thing known as the cataract, in some people. So, the ideal setup will STILL have to be
very subjective. Eyes aren't uniform in their performance.


CJ
post #36 of 845
Quote:
Originally Posted by cmjohnson
But to get the full benefit of that, you'd need to be in a viewing room that is otherwise COMPLETELY dark. No light AT ALL except from the projected image. ANY other light in the
room is going to result in your ultimate black level being slightly washed out.
It is true that you would need no other light lighting up the screen to where you could see the screen, since the darkest your screen can go is how it looks with the projector turned off. However, we are on the CRT forum here and one of the main advantages of CRTs is the lower absolute blacks. If you have much light in your room making your screen visible this advantage just doesn't exist against good digitals because many of them can be used on gray screens in situations like that for better blacks and CR.
Quote:
Originally Posted by cmjohnson
I'm not sure that that's even a good idea, to try for an utterly dark viewing room.
Your room can be white. It is just a matter of not having other lights on. Those who want lights on should consider that the on/off CR advantage of CRTs pretty much disappears, as I mentioned.
Quote:
Originally Posted by cmjohnson
Also, consider this: The lower limit of how little light you can perceive may be different than
what I can, for physiological reasons. As we get older, the lenses in our eyes lose a bit of their transmissivity, which is a prime cause of night blindness. And then there's the
thing known as the cataract, in some people. So, the ideal setup will STILL have to be
very subjective. Eyes aren't uniform in their performance.
It is true that these things vary by the person, but everybody can view blackout conditions in real life. They just might not need the level of light to be as low to perceive no light as someone else. As we get older our ability to see darker stuff does go down (this results in lower Contrast Sensitivity Function scores) and on the surface it probably seems that this means we want everything to be less dark. This is true for the brighter parts of images, but the just-noticeable-difference comes in here and doesn't mean that we want the anchor point to be raised up. If the absolute black is anchored at no light and the next step up is kept at some brighter level, then in any scene (including mixed scenes) it should be easier to differentiate the shadow detail than if that absolute black level was raised up and the next step up was kept constant. In other words, I believe as we get older we want just as much (or more) on/off CR, but we just want things to come out of the absolute black level faster and probably want brighter images overall. In short, we may want video 17, 18, ... to be brighter as we get older, but I don't believe we want video 16 to get brighter (or whatever the black level is at the current APL with this moving).

--Darin
post #37 of 845
Quote:
REC.709 calls for an absolute black level that is darker than your 200k:1 level (since it calls for no light)
Darin: I'm looking at 709, and I'm not seeing quite where it says this except if you're getting this from where it describes the gamma function+tail. In which case, due to my having sworn off mathematics, could you show the calculations to get to what you're showing? :)
post #38 of 845
Quote:
Originally Posted by ChrisWiggles
Darin: I'm looking at 709, and I'm not seeing quite where it says this except if you're getting this from where it describes the gamma function+tail. In which case, due to my having sworn off mathematics, could you show the calculations to get to what you're showing? :)
As far as what the absolute black level should be I think it is zero light in any of these, and therefore darker than 200k:1 would make the absolute black level. Even the linear tails start at zero in every case I have found and same with the gammas. I don't have REC.709 here, but doesn't the gamma+tail start at zero?

As far as video 17, I took that number from dlarsen's table he posted here where he applied the linear tail. I thought there was another standard that called for video 17 to be at a CR of something like 3k:1 or 4k:1 to video 235, but I'm not sure of that at the moment.

--Darin
post #39 of 845
Quote:
but doesn't the gamma+tail start at zero?
I think so, but it doesn't really spell it out that I see, just that 0 is less than or equal to luminance less than or equal to 1. So I guess you'd intepret that to say that black should be 0 luminance, though in reality I don't think it ever is on anything that's calibrated. I definitely agree that ideally that's what we should be striving for.

Anyway, that wasn't really my Q, I was interested in the CR numbers. Thanks for the link, I think I glanced over that quickly before.

I'm curious though, why hasn't anyone put out a LUT for a PC for instance with a linear tail, or even what you were talking about quite a while ago of pushing all 16 values down to say 0 or something. I'd be interested to see what would happen on a CRT.
post #40 of 845
Ok, if I had $10K and already have CRT in my life why would I be deemed insane for not buying a used G90 vs. buying something digital instead?

No, I am not asking for myself, but for anyone that fits this bill.
post #41 of 845
OK, I'll bite. Around that price the Sony Ruby seems to be the main digital competitor for a G90.

- warranty
- ease of use
- 1080P. I know the G90 will do it, but would still need a pretty good setup to do it justice.
- brightness
- digital signal path
- low sound level
- no convergance


Just a few points of the top of my head.
post #42 of 845
Quote:
Originally Posted by Semisentient
OK, I'll bite. Around that price the Sony Ruby seems to be the main digital competitor for a G90.

- warranty
- ease of use
- 1080P. I know the G90 will do it, but would still need a pretty good setup to do it justice.
- brightness
- digital signal path
- low sound level
- no convergance


Just a few points of the top of my head.
So, from this the ignorant should take away from your points that the G90:

- Needs a warranty
- Complex to use
- Is dim, even compared to a 500-hour G90 vs. Ruby condition
- The digital input card is urban legend and not a realty
- Too loud
- Has convergence issues

I read your words and intereted as such.
post #43 of 845
I'm always interested to read why people want super bright sets. To me, anything over 600 lumens is plenty bright, and anything substantially over 1200-1300 lumens is too bright in a true 'theatre' situation.

If you're putting a 3000 lumen digital into a bright living room, I'd hardly call that a 'theatre'/

Curt
post #44 of 845
Quote:
OK, I'll bite. Around that price the Sony Ruby seems to be the main digital competitor for a G90.

- warranty
- ease of use
- 1080P. I know the G90 will do it, but would still need a pretty good setup to do it justice.
- brightness
- digital signal path
- low sound level
- no convergance


Just a few points of the top of my head.
These are valid points, but I think they can be worked around. The key in my opinion is buying the G90 from a good reseller. I plan on buying a G90 in the near future, and I plan on using Terry. The way I see it is this:

warranty- a good reseller will work with you after the sell to fix any problems.
I know it is not the same as a factory warranty, but I am more than
happy to have Terry work on my unit in house. I know he won't
be satisfied until the job is done right, and he has always been
entirely reasonable in regards to price.

ease of use- with a good setup, I think this is a moot point. Even my wife can
operate my current CRT with the Pronto remote.

1080p- I have seen 1080p on my 9" CRT and it is stunning. I know it will be
even better on a G90. Is the Ruby going to be that much better?

brightness- I get 9fl from my current 9" machine and never feel lacking.

digital signal path- This is the only thing that slightly worries me. The HDDVD
dilemma. I am confident though that if HDCP is enacted on
component signals, someone will have a work around.

quietness- my current 9" CRT does not bother me with sound. If it did, I would
build a hushbox.

convergence- All about the setup. I have only touched my convergence once in
the past six months.

I know the digitals are getting really good now, and I think that is great. But as long as we still have machines like the G90 and reliable, experienced resellers like Terry, Curt, and Tim, I am sticking with CRT. Just my .02 cents.
post #45 of 845
Quote:
Originally Posted by Curt Palme
If you're putting a 3000 lumen digital into a bright living room, I'd hardly call that a 'theatre'/ Curt
Actually, considering the PQ of the public theaters maybe the elevated black-level is more easily achieved by using 3,000 lumens. :D
post #46 of 845
Quote:
Originally Posted by Curt Palme
I'm always interested to read why people want super bright sets. To me, anything over 600 lumens is plenty bright,
Curt
I don't really think people want "super bright' projectors. It's just after seeing a digital ( any digital) Most CRT looks pretty dim. My friend just bought a Sanyo Z1 so I helped him make a mount and install it. The actual PQ is not something I could live with but the relatively low brightness ( around 350-400 LU-according to HC) for a digital still spanks any CRT I've owned. I honestly thought there was something wrong with my Marquee when I turned it on after watching the Z1.

I do not like a super bright image but PQ a side, more brightness with good PQ is better than less brightness with good PQ. I often wish my Marquee was just a little brighter.
post #47 of 845
I reemmber when a friend brought over his old NEC XGA-based business projector. He wanted to see what it would look like with an HD source I had setup in a room with a 7" air-coupled CRT projector and fairly good control of ambient lighting.

I remember the added brightness made the colors seem more punchy (saturated) and also remembered this was common in an LCD projector. It was an in your face wow experience for me. Unfortunately, I couldn't watch a lot of my favorite movies without killing > 50% of the brightness because of the high black level.

Now take that experience with another experience that followed several months later with the Sony HS51. A much better experience (higher contrast, lower black-level), but this was achieved, to a major extent in the brightness being much lower.

I guess what really bothered me regarding the process of going from a Sony D50 to spending up to $10K on a digital was that a person doing this felt nothing 'in between' a D50 and G90 was worthy enought to spend even $4K on (thinking 8" LC projector, here).
post #48 of 845
I am in a similar dilemma and really would like to be convinced to make the move to digital. My M8500 (granted, that's no G90) throws a beautiful picture but I'm just tired of dealing with that huge monster and its associated quirks (like things breaking down).

However, I don't think I'm willing to spend $10k on a replacement, either. More like $5k tops. Also, with the Ruby the $10k is only the beginning - you also need a scaler. My Faroudja is currently fixed at 720p.

So far, its not real encouraging for me being able to make the move to digital - but, since I still have several months before my room will be ready, maybe time will help me out.
post #49 of 845
Quote:
Originally Posted by Rinx
I do not like a super bright image but PQ a side, more brightness with good PQ is better than less brightness with good PQ. I often wish my Marquee was just a little brighter.
That's a very odd thing to hear for me personally, I have never wished my 8500 was brighter. I'm running a 84" wide in a dark room with very dark ceiling. Anything above C-37 is uncomfortable IMO. I'm curious as to screen size, tube condition, and light control do you have in your room? I mean if your pushing C to 60/70 or more and it's still not bright enough something is wrong.

Quote:
Originally Posted by ebr
I am in a similar dilemma and really would like to be convinced to make the move to digital. My M8500 (granted, that's no G90) throws a beautiful picture but I'm just tired of dealing with that huge monster and its associated quirks (like things breaking down)
another unusual comment,sssuming the LVPS P14 issue is addressed the Marquee's are extremely reliable. What problems have you had?
post #50 of 845
Two crapped out HVPSs in two years.
post #51 of 845
Quote:
Originally Posted by ebr
I am in a similar dilemma and really would like to be convinced to make the move to digital...However, I don't think I'm willing to spend $10k on a replacement, either. More like $5k tops. Also, with the Ruby the $10k is only the beginning - you also need a scaler. My Faroudja is currently fixed at 720p.
Sony's price tag on the Ruby is an act of desperation. Sony is currently get its butt kicked in consumer electronics. They are laying off people right and left, etc.

Now, their act of desperation should drive the price of a 720p DLP that used to be $12K (think Sharp, Yamaha, Marantz) down into the $5K range. The Optoma is already in that range (but the H79 started lower priced then the others), but the others will probably join it within a year. Now, can you be happy with one of those instead of an 8" CRT? If so, there is your ticket. I could not be as I've compared them all.

But, the other side of the coin is that the CRT market will likely also respond within a year, so you'll be faced with the dilemma of one of the 720p single chip DLPs for $4K or a 9" CRT for around that amount. Would you really take a 720p single chip over a 9" machine?

Dave
post #52 of 845
I don't think a single chip DLP is ever going to be in my future. Even a single rainbow would make me regret that forever. So, I've gotta hope that LCD gets acceptable blacks or LCOS or 3-chippers come down in price.
post #53 of 845
Quote:
Originally Posted by ebr
So, I've gotta hope that LCD gets acceptable blacks or LCOS or 3-chippers come down in price.
Depends upon what you consider "acceptable". A dynamic Iris makes the blacks about as good as any digital. The problem with LCD is going to be SDE even with 1080p. I can see the SDE on an HS51 from >2x screen width. I've done the calculation and even if that thing had a 1080p chip, I'd still see the SDE from 1.6x screen width and I like to watch from closer to 1.4x. I think LCD will only be an option for you if you like to sit far away.

Dave
post #54 of 845
You may be right - the SDE also drove me bonkers on the Z3 (I could see it clearly from my second row) - especially in fast moving or panning scenes. The SDE kind of became a motion artifact because, when the image itself had normal motion blur, the only thing in focus was the space between the pixels which made it really stand out.
post #55 of 845
Quote:
Originally Posted by Curt Palme
I'm always interested to read why people want super bright sets. To me, anything over 600 lumens is plenty bright, and anything substantially over 1200-1300 lumens is too bright in a true 'theatre' situation.
This depends on screen size and more lumens doesn't have to mean brighter images. It can mean a darker screen for better CR (rejection of reflections off walls for better ANSI CR) or more of both ANSI CR and on/off CR with any lights on or coming in.
Quote:
Originally Posted by Person99
Depends upon what you consider "acceptable". A dynamic Iris makes the blacks about as good as any digital. The problem with LCD is going to be SDE even with 1080p. I can see the SDE on an HS51 from >2x screen width. I've done the calculation and even if that thing had a 1080p chip, I'd still see the SDE from 1.6x screen width and I like to watch from closer to 1.4x.
The Panasonic AE900 has no SDE at 1.4x to anyone I know. There may be other issues, but SDE even at 720p isn't one of them.

--Darin
post #56 of 845
Quote:
Originally Posted by ebr
Two crapped out HVPSs in two years.
ahh yes, the Marquee's Achille's heel. :( I'm supposed to start work with an EE on redesigning parts of this supply to make it more reliable, but no one wants to send a broken one for the R&D work. I even offered to pay for the shipping. :confused: Well I hope to get one soon, when you think about the original Spellman design is 12 years old now there's got to be room for major improvement.
post #57 of 845
Quote:
Originally Posted by darinp2
There may be other issues, but SDE even at 720p isn't one of them.
I'm guessing the "other issues" is enough to keep him out of one, but I could be wrong.
post #58 of 845
Actually, its just black level and SDE that are the big drawbacks for me. With the Z3 I can clearly see pixels from my second row almost 2x screen width back - especially on motion scenes. A whole bunch of people have said the same thing as darin - that they don't see any SDE - but I'm not one of those people.

I haven't tested out DLPs (or better LCDs than the Z3) so I was hoping they were better on those issues.
post #59 of 845
Quote:
Originally Posted by ebr
A whole bunch of people have said the same thing as darin - that they don't see any SDE - but I'm not one of those people.
Darin was only saying that about the AE900--not other LCDs. I can see SDE like a madman, but I will admit that I don't really see it from 1.5x with the Panny. However, something about the Panny picture lacks punch, vibrancy, and depth to me.

The AE900 has what panny calls their "smooth screen" technology. Really, it is a lens that introduces a seperation and blur so that the SDE is minimized. Think of it as trying to simulate the natural gaussian blur of a CRT spot and you are pretty close. They actually have less SDE than a 720p DLP.

You could go check one out and see if you like them. They are cheap--that's for sure.

Dave
post #60 of 845
One other thing ebr which may or may not be a deal killer. Assuming you don't like judder in your film viewing, good luck finding one of these cheap digital PJs that will do 72 Hz!

Dave
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