darin's contrast ratio thread - Page 7 - AVS Forum
Forum Jump: 
 
Thread Tools
post #181 of 754 Old 10-17-2005, 08:03 PM
AVS Special Member
 
HoustonHoyaFan's Avatar
 
Join Date: Jan 2003
Location: Houston, TX
Posts: 3,964
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 20
Quote:
Originally Posted by CaspianM
I spent about 20 min there. I played with auto a bit and found in some scenes from HD net it was lagging behind in some rapidly varying brightness content. So I turned to On.
If you notice and are bothered by the rate the DI changes, the HS51 is not for you. CLK noted in his review that the HS60's DI is fasterthan the HS50. The Panny 900 has the fastest DI, speced at 60fps, so may be a better option. In any case DI-On is the worst mode in which to view the HS51.
HoustonHoyaFan is online now  
Sponsored Links
Advertisement
 
post #182 of 754 Old 10-17-2005, 08:08 PM
AVS Special Member
 
HoustonHoyaFan's Avatar
 
Join Date: Jan 2003
Location: Houston, TX
Posts: 3,964
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 20
Quote:
Originally Posted by darinp2
While I think they are the same concept at this point I think the Panasonic SmoothScreen might have more of a smoothing effect than the IMX. I would have to do more testing, but I think they are slightly different.
--Darin
I stand corrected. I have seen a friend's IMXed HS51, and it does have a similar smoothing effect to a Panny 700 I saw. The IMX seened to be sharper than the Panny however, so you are correct, they are slightly different.
HoustonHoyaFan is online now  
post #183 of 754 Old 10-18-2005, 08:54 AM
AVS Addicted Member
 
Gary Murrell's Avatar
 
Join Date: Jul 2003
Location: Kentucky
Posts: 10,927
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Black issues fixed aside(with back lighting) no way I could stand a 720p unit, I spotted SDE easily at almost 3x width, maybe 1080p at 2x would work for me

I think that the HS51 with bias lighting, a IMX lens and 20/20 vision would be a pretty decent setup ;)

I am currently happy with my Mits RPTV, but 2/3 years down the road I am already planning a massive new HT room and it will have Rear Projection from a Front PJ, I am so tired of dealing with issues with the PJ in the viewing enviornment, can't wait :)

-Gary
Gary Murrell is offline  
post #184 of 754 Old 10-19-2005, 04:56 PM
AVS Special Member
 
Gary Lightfoot's Avatar
 
Join Date: Jun 2000
Location: Surrey, UK
Posts: 4,487
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 31 Post(s)
Liked: 44
I didn't realise this thread had my H78 (non DC3) mentioned, but thought I should put a few things straight.

My H78 when at home is calibrated to D65 via the DVI input using 2 filters to increase contrast and improve the black level. Contrast is 2707:1, and ANSI capable of well over 400:1 when I measured it in almost ideal conditions, so the 500:1 Darin mentioned looks attainable (such as in his room). The screen gain is 1.25 (Draper M1300), and I use a Prismasonic H1000 anamorphic lens for a constant height 8ft wide 2.35:1 setup, and this helps to smooth the image a little, as well as use all the pixels for 2.35:1 content and improve image brightness. It's fed from an HTPC with a Radeon 9600.

I'd already seen JimmyTheSaints G90 and so far it has produced the best image overall that I've seen from any pj so far, and he asked if I could bring my H78 round some time so that's what we did.

Unfortunately we couldn't source a DVI cable (mine is in the ceiling and a pig to remove or install) so we could only use component. My H78 isn't calibrated for component so it was initialy using out of the box settings and my two lense filters. I did try using the DVI settings on the component input which did tame the red push caused by the filters, but it still wasn't right, with the colours looking a little muted. Hardly ideal but we didn't spend any time trying to get better colours etc.

We did set the black level but we couldn't get the white level set because we couldn't see the white bars (Avia needle pulse test) - they were being clipped by the source or scaler for some reason and we didn't spend any time trying to fix that - I didn't think it was going to adversly affect things as much as not being able to set the black level may have. We were projecting roughly an 8ft wide 16:9 image which was giving less than the 9ft lamberts I have in my set-up for the same width. The screen was around unity IIRC, and without the anamorphic lens the H78 was down on lumens - it was running in eco mode but we didn't try the high lamp mode which would have increased the brightness (and fan noise).

The room was darkish brown at the front near the screen, and the rear was light cream at the back above the chair rail and dark brown below, along with a mirror on the wall. This did have an impact on the black level and the H78s blacks were a lot worse than I have in my mostly 18% grey room at home. It also elevated the black bars above scope content from the G90.

DVDs tend to look a bit chunky from around 1.5 x seating distance on the H78 but look OK to me from around 1.85 seating distance on a 7ft wide 16:9 screen (my previous setup). The H1000 lens allows me to sit at 1.5 distance and I can't see pixels or screen door on the 8ft wide scope screen. Here it was said on that pixels could be seen on the 16:9 screen until at 2.5 seating distance though I couln't see them myself (and I tried to see them), possibly because I'm used the the type of image the H78 gives and not the smooth image of the CRT.

The G90 is one hell of a pj, even in the 'compromised' conditions of the room it was in, so I'm looking forward to seeing it in a more ideal room when JST gets his extension built (provided I get an invite of course, hint. :) ).

I was dissapointed with how the H78 looked on the day, but even at it's best and in ideal conditions it was unlikely to match the G90. Some things I wanted to see - it produced a very good full white field with no obvious colour uniformity issues that some CRTs have, and the greyscal IRE bars looked good from black to white which was also the best I've seen in my limited CRT viewing experience, and similar to what I am use to from a digital. It may not have been at D65 but it didn't show any obvious tints in the bars. It made everything we viewed look good too - it wasn't soft and even poor dvd transfers were smooth and noise free.

I have seen better shadow detail rendition in one particular scene on the Sim2 C3X but that was in better room conditions, and I think that was a good example of ANSI showing that it is also an important part of image reproduction. Goodfellas opening credits were used to show some slight flaring, though this wasn't too bad at all and not as bad as haloing can be.

Something I have noticed though is that there isn't more detail in the shadows which is something I found surprising. I also didn't see more depth either. I did see inky blacks though. I'm coming to the conclusion that the source material we currently have doesn't have a huge CR in the first place - maybe up to 3500:1 but I've seen it said that the film cameras themselves limit recordable CR to 1000:1 (big surprise I must say), with the print processing increasing that to maybe 4000:1 by improving the black content (using silver nitrite?? I think War of the Worlds had something like that done to the print IIRC). Higher CR will give better blacks though, so if the source CR is limited, higher CR will only give a better black level for a given white level, and not more detail.

I'm intrigued by the workings of CRT so have a couple of used units coming my way to have a play with. Nothing big but something I can mess around with to see how they work and how they will measure with Colorfacts etc. I'd like to have a closer look at a G90 in that respect but that will have to wait until I know more about the technology and provided I get the opertunity.

It was a great day and JST is a perfect host, so many thanks again for allowing it to happen. :)

Gary.

Quote:
Originally Posted by elmalloc
Who says Cameron is "right" and why do we care about him so much - lol!

I trust Gary Lightfoot more than James Cameron.
Gary Lightfoot is offline  
post #185 of 754 Old 10-19-2005, 05:39 PM
AVS Special Member
 
mikecazzx's Avatar
 
Join Date: Jan 2004
Location: Nw Indiana, Chicago Suburbs
Posts: 1,140
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by Gary Lightfoot
The room was darkish brown at the front near the screen, and the rear was light cream at the back above the chair rail and dark brown below, along with a mirror on the wall. This did have an impact on the black level and the H78s blacks were a lot worse than I have in my mostly 18% grey room at home. It also elevated the black bars above scope content from the G90.
Gary.
The room totally effects the perceived contrast I have found. Any light colored paint, ceiling or carpet ruins the picture quality.

"Thank you" to the forum members who tirelessly help the new members of this fraternity we call Home Theater.
mikecazzx is offline  
post #186 of 754 Old 10-19-2005, 05:43 PM
AVS Special Member
 
mikecazzx's Avatar
 
Join Date: Jan 2004
Location: Nw Indiana, Chicago Suburbs
Posts: 1,140
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
The G90 is king for sure. I think things have come a long way in the last 2 years and I hope they continue improving black levels on the DLP's. Partially due to the DC3 chip and partially due to my dark room, low reflecting setup - I have found a DLP that impresses me greatly.

It took about 2 years of watching them improve and prices coming down and seeing about 20 of them in various conditions for me to really test one.

"Thank you" to the forum members who tirelessly help the new members of this fraternity we call Home Theater.
mikecazzx is offline  
post #187 of 754 Old 10-19-2005, 09:23 PM
AVS Special Member
 
Ericglo's Avatar
 
Join Date: Oct 2004
Location: Just below the US in South Florida
Posts: 6,288
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 109 Post(s)
Liked: 43
Quote:
Originally Posted by darinp2
I wasn't really thinking of Tryg partially because I've never been to any comparisons with him except for screens and there I did correct something and gave my differing opinion. And most of the people I was thinking of as reasonable were CRT owners. As far as projectors, Tryg has his opinions and I do tend to take a lot of his posts with a grain of salt, other than knowing that he prefers really bright, rainbows drive him crazy, and he has been on a 1080p kick for a while, but I believe it is pretty much clear that they are his opinions. To me that is much different than factual information. Or statements that really will throw people off. Right now I can't think of anything that Tryg has said that has been false recently (although I did need to clarify some stuff he posted about what I had said from CEDIA where I probably wasn't clear and I did that) and I just expect Tryg to be obviously outrageous about his opinions.

If you think I haven't had some pretty big disagreements on the digital forum then maybe you just haven't been reading there long enough. :) I'm not sure how many times we went around about on/off CR there with some people claiming that improvements weren't needed and I was accused of siding with CRTs because I said they were better than digitals in that one department and the digitals needed to improve there.


--Darin
It looks like you did give Tryg a little dressing down. I may have been a little harsh in my statement, but I must confess Tryg has really gotten underneath my skin lately. Actually to the point that I have stopped frequenting the digital forum. It is not that I dislike the guy, but I think a lot of his posts have bordered on trolling. I also think his posts in Dan's thread were way out of line. If you don't like the projector or pricing or whatever, then make a statement and move on. I thought it was in poor taste to sidetrack his info thread and then start a new thread to continue his bashing. Whoops, now I am ranting.:)




Quote:
Originally Posted by darinp2
"Need" is relative. To get the "best results" requires buying a G90 and not a G70, but if we are talking about price/performance then I don't think the H79 requires a scaler. But one can be nice for any of these, especially after the HQV/Teranex scalers come out. And a person could get 48Hz playback of some stuff with an H79 and a scaler. The comparisons I layed out didn't include a scaler as that is definitely one choice. I generally don't use an external scaler with the H79 partially because I hate having to use a PC, but I did just start using a Roku device for some things.

--Darin
Where is the love for the Gennum? Actually, this has been getting on my nerves lately as well. HQV and SO have been beyond hypeing this for over a year with only one product on the shelves so far. Heck, it is funny how people are taking Optoma to task for announcing a product that probably won't be here for around nine months. Really the only reason it bugs me is that some may have put off scaler purchases in anticipation of these scalers. Anyway, you have owned Optoma projectors in the past. What about the Optoma scaler, when it arrives?

Eric

Call AVS For the Best Deals!!!


My new favorite game is Stop the Bots
Ericglo is offline  
post #188 of 754 Old 10-20-2005, 12:29 PM
AVS Special Member
 
Ericglo's Avatar
 
Join Date: Oct 2004
Location: Just below the US in South Florida
Posts: 6,288
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 109 Post(s)
Liked: 43
The NEC and Optoma should be some interesting products. These along with DVDOs VP40(?) and the Nvidia/ATI cards make for a potentially exciting time in image processing. I think (and I am probably wrong) that this will make the biggest improvement in pic quality compared to the decision between the four display technologies.


Ericglo
P.S. - Darin, I went to the trouble of helping get the Calibration forum started (although I would have prefered it to be a little more broader in scope) and you don't even post there.:) What gives? I figured this would be your own little fiefdom.:)

Call AVS For the Best Deals!!!


My new favorite game is Stop the Bots
Ericglo is offline  
post #189 of 754 Old 10-20-2005, 12:36 PM
AVS Special Member
 
Person99's Avatar
 
Join Date: Dec 2004
Location: Flower Mound, TX
Posts: 5,253
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by Ericglo
I figured this would be your own little fiefdom.:)
Too busy working on creating the other fiefdoms to put effort into yet another. :rolleyes:
Person99 is offline  
post #190 of 754 Old 10-22-2005, 09:06 AM
AVS Special Member
 
romanesq's Avatar
 
Join Date: Oct 2004
Location: Hoboken
Posts: 1,174
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Wish a current H78DC3 via digital made the shootout. Of course not everything is possible but would have liked to see a H78DC3 in the mix shot on a gray cheap Optoma Graywolf screen using a HDMI cable with the DVI adaptor to get closer to the better utilization.

That's what I'm using and the blacks are heavy. Very heavy.

Oh well you can't have everything in a shootout.

It's all just a game. I just play to win.
romanesq is offline  
post #191 of 754 Old 10-22-2005, 11:08 AM
Senior Member
 
JimmytheSaint's Avatar
 
Join Date: Mar 2003
Location: UK/USA
Posts: 286
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked: 10
I would like to clarify that I thought the Optoma was a cracking little PJ for the money, but I wanted to point out that it had certain flaws that distracted from the overall viewing of film for me. This I have found inherant with DLP technology (less so with the SXRD Qualia). Whether or not these issues will diminish when a 1080P 3 chip DLP panel PJ hits the market or not, we will have to wait and see.
At it's pricepoint though, it appears to be very good and I even prefered it to the Sim CX3 3 chip DLP (may have been the presentation to blame). It is also nigh on silent with good colour and brightness uniformity. If, however, one can purchase a G70 for the same money and have the availability of a completely light controlled environment, I would advise them to go for the latter. Obviously, a pro install would be ideal, but with a little effort and patience, you can achieve good results calibrating the PJ yourself.

Darin, I would be interested in hearing what mods you have done to improve the performance of your PJ and have you got yourself a Ruby yet?

Gary, thanks again for your time and effort and of course you are welcome back anytime!
:)
JimmytheSaint is offline  
post #192 of 754 Old 10-22-2005, 04:28 PM
AVS Special Member
 
Gary Lightfoot's Avatar
 
Join Date: Jun 2000
Location: Surrey, UK
Posts: 4,487
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 31 Post(s)
Liked: 44
Quote:
Originally Posted by JimmytheSaint

Gary, thanks again for your time and effort and of course you are welcome back anytime!
:)
Thank-you Yas' for allowing me to see the G90 in action and for the food and drink you continuously plied us with!

See you tomorrow at James's and I'll be interested to see how his Ultra compares to the G90. I doubt I'd notice anything obvious without them both in the same room though. You being more familiar with your machine should be the one to notice any differences.

I think you'll be surprised how much the room can make a difference - when you have your extension built, I think you'll easily notice the change in the image, and that's saying something considering how good it is already.

Gary.

Quote:
Originally Posted by elmalloc
Who says Cameron is "right" and why do we care about him so much - lol!

I trust Gary Lightfoot more than James Cameron.
Gary Lightfoot is offline  
post #193 of 754 Old 10-28-2005, 01:57 PM
AVS Special Member
 
Person99's Avatar
 
Join Date: Dec 2004
Location: Flower Mound, TX
Posts: 5,253
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
I was going to post this in another thread, but decided to start a thread because we see this topic getting brought up a lot in digital marketing or by fans of digital technology.

Here is the short version: this whole low ANSI contrast and CRT projectors is WAAAAY overblown and just downright misleading—in the end, it doesn’t matter much.

Here is the long version:

Before discussing the contrast ratio of a device, we first need to understand what the human eye is capable of. The human eye’s ability to perceive contrast is regulated by chemical and physical (iris) factors. Physiologists distinguish between static and non-static contrast perception.

Static contrast perception is the contrast ratio your eye can perceive at any given instant. For a human, this is about 100:1. Non-static contrast perception is the contrast ratio you can perceive over time. For a human, this is about 1,000,000:1.

So, let’s bring this back to a display discussion. This means that when watching a display, in any given instant, you cannot possibly distinguish a contrast ratio in excess of 100:1—it is physiologically impossible. Over time (as the eye moves or scene changes which readjusts the chemicals and the iris), you can perceive a contrast ratio of about 1,000,000:1.

So, what does this mean? This means that at any given instant when watching a display, you are physically limited to 100:1 contrast but as you watch it throughout time, you can perceive up to 1,000,000:1 contrast.

OK, back to ANSI contrast. ANSI contrast is a contrast measurement taken by putting up a checkerboard of full white boxes on a black background. Technically, this is a 4x4 pattern, but measurements are often taken using an 8x8 or 9x9 pattern. The measured ratio between the black and the white is the ANSI CR. On/off CR is measured by measuring a full white screen (or a white window on a CRT or Plasma) and measuring a full black screen and calculating a ratio from that. This on/off CR tells you the full dynamic range the display is capable of.

Back to our eye. At any given instant, we can perceive 100:1 CR. That means 2 measurements taken at the same instant of the lightest and darkest part of the image. ANSI CR approximates this. It should also be noted that a white and black checkerboard is sort of a “worst case scenario†because it is very rare that actual film or video content has a composition similar to this. Also, it should be noted that the ANSI CR on a 9x9 checkerboard pattern will be lower on a CRT than the ANSI CR of a 4x4 pattern even though the APL of them is the same—so actual content greatly effects this measurment. Thus, having a dark scene with a bright object in it actually has a higher contrast ratio on a CRT than a 4x4 checkerboard does while it is about the same CR on a digital as the 4x4 checkerboard pattern. This is crucial when understanding intrascene CR on a CRT. Scenes with a bright object in a dark backround are much more common than a checkerboard-like scene and the CRT has a CR in this situation that almost matches that digital.

You will also see from the above that over time, we can perceive 1,000,000:1 CR. So, dynamic range in a display is critical. Given our low static contrast perception and our huge non-static contrast perception, dynamic range of the display tells us how it stacks up over time. The way this is measured is via on/off CR.

The ambient light in the room (including reflected light) controls the actual CR. For the discussion that follows, we will assume a light controlled room with dark walls.

Just so we have a baseline from which to discuss, film in a theater pretty much has an ANSI CR of 80:1.

So, what are some common CRs? Well, a liquid coupled CRT will typically have a 4x4 checkerboard pattern in excess of 250:1 and a 9x9 checkerboard pattern in excess of 100:1. For a real life measurement, the Sony G90 has been professionally measured to have an 8x8 checkerboard pattern ANSI CR of 130:1.

An air coupled machine will typically have a 9x9 checkerboard pattern around 70-80:1 and a 4x4 checkerboard pattern around 200:1.

Many digital PJs have 9x9 and 4x4 of over 500:1

Now, the typical CRT can have an on/off CR of over 15,000:1. Of course, when calibrated for theater use, that will likely be somewhere in the 6000:1-8000:1 range, but given the capability of the display, a modified gamma curve could be employed to get a higher ratio. A digital PJ will typically have an on/off of less than 5000:1 when calibrated with many down around 2000:1 or 3000:1 (and surprisingly many that people are currently using in their theaters even below that—for instance, on/off of 600:1 for a 1-2 year old digital is not uncommon).

So, as you watch the display, with your incredible 1,000,000:1 non-static CR eye, you will be able to discern the on/off CR of the display both in changes between scenes as well as fade to black scenes. However, with your lowly 100:1 static CR eye, you will only be able to perceive an instantaneous CR of 100:1. Of course, a single scene can have a constant CR and the 100:1 range moves about which is how we get up to 1,000,000:1, but you have to look at a different part of the scene or the scene has to change to readjust where on the scale you are seeing the 100:1.

It is foolish to say ANSI CR is completely unimportant because intrascene CR of over 100:1 can be perceived in very rare circumstances if the light parts are not evenly distributed across the scene and you have a large enough screen such that the light and dark parts of the scene are far enough apart that your iris can readjust by opening and closing—pretty rare in home theater.

It is EXTREMELY rare that a person can perceive the difference between an ANSI 100:1 CR projector and an ANSI 500:1 projector when viewing content.

Raymond Soneira, Ph.D. in Physics, whose career spans research scientist to television-display design, measured various displays with 4x4 ANSI CR ranging from 586:1 to 219:1 and 9x9 ANSI CR ranging from 577:1 to 75:1. Commenting on these measurements, he said, “displaying images with more colors and finer gradations, the eye doesn't really pick up on these contrast differences. For example, to my naked eye the checkerboard patterns on all of the displays appeared to have roughly the same contrast, even though the instrumentation told me otherwise. This has more to do with human visual perception than physical optics and is one of the reasons interpreting contrast numbers is tricky.â€

So, if you’ve not been able to see the benefit of this high ANSI CR on a digital projector, you would not be alone, a research scientist and display design expert can’t perceive much of a difference either—such is the way the human eye works.

It would also be foolish to say on/off CR is all that matters. But, I hope to have shown that this is a real indicator of dynamic range and a very important component of a good viewing experience.

In the end, playing up any single attribute of a display is foolish. The quality of the image is made up of the interplay of several factors.

I’ll leave you with a final quote form Raymond Soneira when commenting on using measurements evaluate the quality of a display (emphasis mine):

“How you slice and dice a display's measurements and specifications can be an endless exercise, depending on how in-depth you, as a buyer, want to go. As a scientist, I find it fascinating to explore the hidden physics in the miracle of sight. It's my hope that a working knowledge of display characteristics will help you make a wiser decision when making display choices. But in the end, it doesn't matter much what the numbers say; it's what your eyes tell you that really counts.â€

Please remember this quote the next time you read a spec sheets or someone preaches numbers to you. In the end, what matters is how good the display looks when you watch it. The simple fact of the matter is, none of us watch a movie with a light meter.

Dave
Person99 is offline  
post #194 of 754 Old 10-28-2005, 02:04 PM
QQQ
AVS Addicted Member
 
QQQ's Avatar
 
Join Date: Jan 2002
Posts: 10,998
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 13
Who wrote that for you? They got quite a bit wrong. But at least you've gotten your digital bashing fix for the day. Have fun.
QQQ is offline  
post #195 of 754 Old 10-28-2005, 02:11 PM
AVS Special Member
 
Person99's Avatar
 
Join Date: Dec 2004
Location: Flower Mound, TX
Posts: 5,253
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by QQQ
Who wrote that for you? They got quite a bit wrong. But at least you've gotten your digital bashing fix for the day. Have fun.
I wrote it from research and medical sources. Did you actually read the whole thing--is your attention span that long? Perhaps Ph.D. researchers that are experts in display design are not as competent as distinguishing CR with the naked eye as some of you, but I'm going to go with them on this.

Secondly, this is not digital bashing in anyway. To quote another forum member, I'm just trying to clear up the "orgy" of misinformation that gets spread. Of course I knew you guys would show up with the FUD soon, but this info should be out there.

BTW, how's that comparison thread from last Christmas going? I can't believe someone with your integrity would outright lie in a public forum. :)

Dave
Person99 is offline  
post #196 of 754 Old 10-28-2005, 02:21 PM
AVS Special Member
 
stefuel's Avatar
 
Join Date: Apr 2001
Location: Marshfield, MA, USA
Posts: 5,883
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked: 13
Quote:
Originally Posted by QQQ
Who wrote that for you? They got quite a bit wrong. But at least you've gotten your digital bashing fix for the day. Have fun.
Excuse me but I suffer from dyslexia. Is it QQQ or QQQ? :D

Chip

Current owner of the last/best AmPro on the planet. The mighty 4600HD, and it's still running...better than Barco's, especially southern ones.
stefuel is offline  
post #197 of 754 Old 10-28-2005, 02:27 PM
AVS Special Member
 
Semisentient's Avatar
 
Join Date: Sep 2003
Location: Woodbridge,Ontario
Posts: 1,417
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by stefuel
Excuse me but I suffer from dyslexia. Is it QQQ or QQQ? :D

Chip
Nope, it's QQQ.

There's no place I can be, since I found Serenity. You can't take the sky from me.
Semisentient is offline  
post #198 of 754 Old 10-28-2005, 02:31 PM
QQQ
AVS Addicted Member
 
QQQ's Avatar
 
Join Date: Jan 2002
Posts: 10,998
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 13
Quote:
Originally Posted by stefuel
Excuse me but I suffer from dyslexia. Is it QQQ or QQQ? :D

Chip
LOL.
Quote:
Originally Posted by Semisentient
Nope, it's QQQ.
You're both wrong. It's QQQ.

You're probably posting on a low ANSI CRT monitor or you'd know the difference.
QQQ is offline  
post #199 of 754 Old 10-28-2005, 02:44 PM
AVS Special Member
 
Person99's Avatar
 
Join Date: Dec 2004
Location: Flower Mound, TX
Posts: 5,253
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
The rate at which you guys respond is truly amazing.

Quote:
Originally Posted by darinp2
I don't know anybody who uses 9x9 checkerboards as ANSI CR is specifically 4x4. I've measured a G70 at close to 125:1 ANSI CR and an AC unit at around 70:1. I would like to see a reference to that 130:1 measurement, as ANSI CR is 4x4 and not 8x8.
Yes, ANSI CR is 4x4. However, much research uses a variety of patterns including denser patterns because the denser the pattern, the worse the CRT does. Also Plasmas vary by APL and pattern density.

Secondly, your measurements are anecdotal. You are not a professional researcher, nor are your numbers published anywhere. I'm thinkin' about going with the pros on this one not Darin heresay.

Quote:
Originally Posted by darinp2
And I would wonder about anybody's vision who couldn't see the difference between 80:1 and close to 500:1 off a screen in an ANSI checkerboard (4x4). It is pretty clear in my theater.
Sorry, I was only going on published research papers. I did not account for your superhuman vision. You will note from above that depending upon your viewing angle and the movement of your eye, you can actually exceed 100:1 in a scene because you are now into the non-static human CR perception. Secondly, that vast majority of content I watch has absolutely nothing like a 4x4 checkerboard pattern in it.

As Art has pointed out, for low APL (alot of movies) or black and white movies, the Qualia won't cut it over the G90.

Quote:
Originally Posted by darinp2
I was wondering what kind of messed up background a person would have to have written that.
I noted the background of the idividual. Sorry he doesn't agree with your CRT bashing--can't help ya here. Oh well.

Quote:
Originally Posted by darinp2
Now I'm not saying that ANSI CR is the be all end all (no value is) or that people will care over some number
Since you are the one oft quoting numbers and ANSI CR, will you then please provide us with the appropriate equation to determine the quality of the display to our eyes given these numbers please?

I must say, it always warms my heart when you quickly degenerate to name calling. This is more telling of a weak position that anything else you can say.

Dave
Person99 is offline  
post #200 of 754 Old 10-28-2005, 02:49 PM
AVS Addicted Member
 
darinp2's Avatar
 
Join Date: Sep 2003
Location: Seattle, WA
Posts: 21,188
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 19 Post(s)
Liked: 62
Quote:
Originally Posted by Person99
Secondly, your measurements are anecdotal. You are not a professional researcher, nor are your numbers published anywhere. I'm thinkin' about going with the pros on this one not Darin heresay.
Are you going to tell us where you got the 8x8 130:1 number for a G90?

Are you going to tell us where you got the 100:1 number?

Quote:
Originally Posted by Person99
I noted the background of the idividual. Sorry he doesn't agree with your CRT bashing--can't help ya here. Oh well.
You told QQQ that you wrote it.

--Darin

This is the AV Science Forum. Please don't be gullible and please do remember the saying, "Fool me once, shame on you. Fool me twice, shame on me."
darinp2 is online now  
post #201 of 754 Old 10-28-2005, 03:27 PM
AVS Special Member
 
Person99's Avatar
 
Join Date: Dec 2004
Location: Flower Mound, TX
Posts: 5,253
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by darinp2
Are you going to tell us where you got the 8x8 130:1 number for a G90?
Man, don't you know how to use Google?

http://www.hdtvexpert.com/pages/vphg90v.html

You won't like it, he also got ANSI lumen ratings way above what you like to quote.

Quote:
Originally Posted by darinp2
Are you going to tell us where you got the 100:1 number?
Google is your friend. You can find it in physiological research papers as well as research papers on display design. For accessibility, I recommend an encyclopedia--I believe most publish this when discussing the dynamic range of the human eye.

Quote:
You told QQQ that you wrote it.
I misunderstood you then. I thought you were refering to the quote by the Research Physicist/Display Designer that said in reality he didn't see much difference in the CR between checkerboard patterns although his instruments told him there was one. Given his background and accurate measurements, his opinion would carry more weight then any of ours.

Part of his point was human physiology limits this, the other part is aside from the rare scene (not even an average of once per film) you won't be able to perceive the difference in ANSI CR on the VAST MAJORITY of content that is not test patterns.

This last point is quite simply the thesis of my post. The genesis of this post was visitors to my HT that could not perceive this digital ANSI CR benefit on over 95% of material (considered by running time not movie instances) when viewing the CRT. They could however, percieve the benefit of the on/off CR in just about every movie since most contain a fade to black and many are very dim. Another post today prompted me to finish this and post it.

Dave
Person99 is offline  
post #202 of 754 Old 10-28-2005, 03:32 PM
Senior Member
 
Soapsuds's Avatar
 
Join Date: Sep 2005
Location: Mississauga, ON, Canada
Posts: 381
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Soapsuds is offline  
post #203 of 754 Old 10-28-2005, 04:47 PM
AVS Special Member
 
Person99's Avatar
 
Join Date: Dec 2004
Location: Flower Mound, TX
Posts: 5,253
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by darinp2
This doesn't do it for me.
But your anecdotal stuff does. Interesting. You could also note the camera CR. You can also google for this info. Just so you know, television guidelines are to construct scenes around the expectation of a CR of 50:1 for the viewer.

Quote:
Originally Posted by darinp2
As I stated, a lot of people get confused and think that a CSF score of 100:1 means that people are limited to seeing 100:1 contrast ratio instantly. That article just says, "Human Eye -- Contrast ratio = 100: 1". It doesn't lay out what they mean or where they got that and we know that people can see more contrast than 100:1, given that there are different kinds of contrast ratio and I think we can all agree that people can see well over 1 million to one contrast ratio total.
Your comments show you don't understand static and non-static CR. And actually, we can't see "well over" 1 million to one non-static CR. It is actually pretty close to 1 million to one.

As I've now said three times in this thread, saccades "resets" your static CR range so on a scene you can see greater than 100:1--in an instataneous sample, you cannot. This coupled with other factors is why you cannot see the difference on the vast majority of content when watching normally (not looking for CR differences).

You seem to be attacking some of the nitpicky things instead of the thesis of the post. The main thesis is don't buy a display based upon numbers. Watch it for yourself and see what you like.

Do you actually disagree that is a valid way to determine the display you want to buy? You actually believe that it is an inferior method to basing it upon the measurements and comments posted in a public forum by some guy whose credentials you don't know?

The other significant claims you seem to miss are:
1) On the VAST MAJORITY of content when you watch it for pleasure not analysis, you will not be able to perceive the ANSI CR difference. You need to view an uncommon scene to do this, not fixate your eye at one point (say the on screen action) while watching this scene, and set out to observe the CR.

2) In almost every movie, you will be able to percieve the difference in the on/off CR between projectors thanks to the fact that just about every movie spans the the majority of the dynamic range of a display.

But, the bottom line is: don't be baffled or wowed by numbers. Go see the displays and see what you like the best. You don't agree, but I think most will come to the same conclusion as the experts at WSR and TPV. But, what you and I think people will like doesn't matter at all. What they like for themselves is all that matters.

Well, to the last sentence, I should add a caveat. Since the high frequency flashing light of DLPs bothers between 10% and 15% of the human population, if you like to have people over to watch movies, you may not want to choose this technology even if you prefer it.

Dave
Person99 is offline  
post #204 of 754 Old 10-28-2005, 05:28 PM
AVS Special Member
 
Person99's Avatar
 
Join Date: Dec 2004
Location: Flower Mound, TX
Posts: 5,253
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Again, you fail to acknowledge the fundamental thesis and agree or disagree with it. The fundamental thesis is that watching the display is the single best way to evaluate it and decide what you like, yet you only want to talk measurements. Priceless

All the other stuff is just to explain why when normally watching a movie you may be puzzled when you don't see what the big deal is in one of the three most oft touted advantages of a digital PJ over a CRT.

Actually, I've compared a very very good LC and a non-LC machine side by side. I can see the CR difference, but I have to look for it. On the vast majority of film content when watching the movie (and not looking for differences) I don't really see it. In fact, showing the average person the two PJs side by side most of them are watching the movie and don't see the CR difference. I have to point it out for them and tell them to look for it.

Now, the big difference that I do always see haloing on the non-LC. But again, that is not even on 5% of the content.

You may watch movies to evaluate the projector's performance and constantly look for intracene CR. But, do you also look for rainbows, dithering artifacts, gray-blacks, dust blobs and SDE when watching movies? If so, more power to you. I watch movies to enjoy them on a display that gives me the best movie experience 95% of the time. To each their own.

Dave
Person99 is offline  
post #205 of 754 Old 10-28-2005, 06:25 PM
QQQ
AVS Addicted Member
 
QQQ's Avatar
 
Join Date: Jan 2002
Posts: 10,998
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 13
Quote:
Originally Posted by Person99
Again, you fail to acknowledge the fundamental thesis and agree or disagree with it. The fundamental thesis is that watching the display is the single best way to evaluate it and decide what you like, yet you only want to talk measurements. Priceless
Strange, I thought you were trying to make some claims about ANSI CR not mattering. But now you're telling us that "the fundamental thesis is that watching the display is the single best way to evaluate it and decide what you like". Boy, I sure am glad you taught us all that. You mean I should watch a display to evaluate it and not just rely on measurements? Oh my God, I bet none of us ever thought of that. Thank God you found that quote from your scientist and highlighted it in bold for us. And to think that all of this time we've all been basing our decisions on measurements. Thank you for showing us all the light.

Darin, I'm afraid now that person99 has enlightened us, I'm not too happy with you. All this time you've been telling us to not watch the display but to base out purchasing decisions on measurements and I believed you. But wait a minute, now I'm confused. I just did a search and can't find a single post out of your 8000+ where you tell anyone that. Nevertheless, thank God person99 found that quote from a scientist. I never thought of that. I mean, I've read it from 1001 reviewers and probably 1,000,001 + people have said similar things at some point or another but until person99 quoted this scientist it just never hit me.

Next thing you know someones going to tell me I should purchase a speaker after listening to it instead of measuring it. Now THAT would take the cake.
QQQ is offline  
post #206 of 754 Old 10-28-2005, 06:39 PM
AVS Special Member
 
Person99's Avatar
 
Join Date: Dec 2004
Location: Flower Mound, TX
Posts: 5,253
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
QQQ, since I'm not sure you could make it to the bottom of the original post, read the last two paragraphs if not clear on the message.

Also, let me just point out, that Darin is always worried about measuring and not watching. If you guys cared about watching, you recommend that everyone posting in the digital forums see a CRT to see if they like it, but you don't--actions speak louder than words.

The CR discussion could go on for 72 pages, so lets just simplify and say a PhD'd research physicist who has specialized in display design claims, "“displaying images with more colors and finer gradations, the eye doesn't really pick up on these contrast differences. For example, to my naked eye the checkerboard patterns on all of the displays appeared to have roughly the same contrast, even though the instrumentation told me otherwise. This has more to do with human visual perception than physical optics and is one of the reasons interpreting contrast numbers is tricky.†I provided an explanation for this phenomenon in my post.

Darin and QQQ, whose publications I've not been able to find or whose qualifications I've never seen. disagree.

Dave
Person99 is offline  
post #207 of 754 Old 10-28-2005, 07:08 PM
QQQ
AVS Addicted Member
 
QQQ's Avatar
 
Join Date: Jan 2002
Posts: 10,998
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 13
Quote:
Originally Posted by Person99
QQQ, since I'm not sure you could make it to the bottom of the original post...
I rarely make it to the bottom of any of your posts just as I don't stop to look at grotesque accidents but can't help but slowing down for them. Sometimes I get disgusted that I even have to read part of them, but then I remind myself that it’s a choice and that besides, just as I feel sorry for the person involved in the grotesque accident, I should feel sorry for the guy who writes such posts.
QQQ is offline  
post #208 of 754 Old 10-28-2005, 07:29 PM
AVS Special Member
 
Jesse S's Avatar
 
Join Date: Jul 2002
Location: Toronto, eh?
Posts: 3,503
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Forget all that science. You can have 1,000,000,000:1 contrast but if a display can't do black it still can't do black.

Go away digital shill.
Jesse S is offline  
post #209 of 754 Old 10-28-2005, 08:07 PM
AVS Special Member
 
Ericglo's Avatar
 
Join Date: Oct 2004
Location: Just below the US in South Florida
Posts: 6,288
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 109 Post(s)
Liked: 43
Wow, someone read the link in my sig.:) I think it or something similar should be required reading before posting in any of the display forums.

Now on to the topic at hand. The author also says this number flaps in the wind more than any other. What should be noted is that the displays that were measured were not front projection. So, I will neither agree or disagree, but I would like to see a double blind experiment to see what the results would be. To really do this correctly and be scientific about it, ANSI should be the only variable in the viewing equation. A way would be needed to vary the ANSI figure in one display and then have people view content to see at what figure diminishing returns sets in. I realize Dave is trying to state something else, but it would be interesting to see what ANSI number diminishing returns sets in.

Darin,
Did you ever measure the ANSI of Guy's pj after he masked it? I would be curious how much masking helped.

Ericglo

Call AVS For the Best Deals!!!


My new favorite game is Stop the Bots
Ericglo is offline  
post #210 of 754 Old 10-28-2005, 08:13 PM
AVS Special Member
 
CZ Eddie's Avatar
 
Join Date: Nov 2000
Location: Austin TX, USA
Posts: 7,067
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
Liked: 13
Someday, somewhere... someone will go back through all the threads between Person99 and Darinp2 and type it all up into one consolidated thread. Unfortunately for me, even if it's all compressed by 99%... that would still most likely be 999 million words too long.

"The boom is dead, long live the bass"
CZ Eddie is offline  
Closed Thread CRT Projectors

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off