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Where does image depth come from with CRTs?

Discussion in 'Projectors, Screens & Video Processors' started by Welwynnick, Jun 22, 2005.

  1. Welwynnick

    Welwynnick
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    People always say that CRT projectors achieve the sort of three-dimensional image that digital PJs cannot, and there's no denying that. But how do they do it?

    It is said it's because they have higher contrast, so that a highlighted subject can stand out from an inky black background. Thinking about it, I'm sure it helps, but I don't think it's the explanation. You can still get good 3 dimensionality from images that have relatively little contrast.

    It's also said that it's because well set-up CRTs don't suffer from obvious scan lines or pixels, like CRT TVs or digital displays. They don't have the screen door effect, that draws your eyes to the screen, like looking at the smears on the glass in the window, rather than looking through it. Well I'm sure that helps, too, but I don't think that's it either. The image itself is formed in two dimensions on the projection screen, and it makes no difference whether you watch with one eye or two, because there is no binocular effect.

    So how, then? I predictably think back to stereo audio, where good systems are credited with depth as well as breadth to the reproduced audio image (best perceived with closed eyes, of course). With only two speakers, there is no physical depth, so I presumed it was a perception created by all the clues you hear without realising it. All the tiny echoes and reverberations that you hear in real life that make it through the recording and reproduction chain give you clues about the original sound stage that allow you to recreate it in your imagination.

    With a poor system, like a CD in a DVD player, although the body of the sound is still recognisably there, the fidelity and focus is lost, so you no longer get all the original clues, and you no longer feel as if you are there.

    So with projection, we perceive depth in the video image, not from an actual 3D reproduction, but from clues about the original scene. I think one of the best clues is the depth of focus of the camera lens. With the subject normally in focus, you can make it stand out with a telephoto shot or large aperture, which will throw the background out of focus. Apart from binocular vision, that is something you would have seen (to some extent) if standing by the camera. I think there are lots of other clues as well, even if I don't know what they all are. Atmospheric haze or smoke behind the subject is one, the field of corn gradually going out of focus, or the audible depth of field may be another.

    Whatever the clues are, I think they will only be reproduced if the system has good fidelity, and doesn't lose all the information that you would have seen, without realising it, at the original scene. If the background is out of focus, you can only tell if you can see the subject sharply enough to see that he is IN focus. The mountains on the horizon are not reproduced in saturated colours because of haze, so you cannot have Freeview colour-by-numbers colouring.

    I think depth comes from everything, not just one or two aspects, and they ALL have to be there to get the being-there feeling. It's not good enough to say "I've 720 lines" or "I've got 1000:1 contrast" or "I've got a million pixels" or "I've got a billion colours". You've got to have everything right.

    Now please don't all jump down my neck because an upstart has had the temerity to disagree with accepted wisdom; these are just some thoughts that have been bubbling around for a while, and I'd like to know what other people think.

    regards, Nick
     
  2. Gary Lightfoot

    Gary Lightfoot
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    Hi Nick,

    Great question IMHO. :)

    Judging from what I've seen with my own pjs contrast does seem to be an important factor. Going from 1250:1 CR @D65 on a digital NEC HT1000 to 2200:1@D65 using colour correction filters which allowed higher green and blue contrast settings to be used, I found that there seemed to be more dimension to images, maybe because I could almost see 'into' it more.

    Having limited CR means large areas of what should be shadow detail become flat black (or dark grey with digital) so you've reduced the depth of the image and the amount of visible detail. Having a high resolution display is all well and good (provided the source can be resolved) but you can limit the detail you can actually see by having a reduced CR. To prove it you can simply add some light into your room while the display is on. The blackest black you can get from the screen is what you will see without the pj turned on, all else being equal. Add some light, and that's your black level - a dull white. Turn on the pj and the CR will be dramatically reduced, depending how high the black level floor is. It's simple maths - if black is 0.0015ft lamberts and white is 12 ft lamberts, you have 8000:1 CR (i.e a Williem Phelps calibrated G90 is around 8400:1). Add more light - say double the black level to 0.0030ft lamberts and you've halved the CR. That's not a lot of light added to your black level, so you can see just how important good light control is in a room. Just put on a small lamp and watch the depth of field and dark area detail diminish. Got any LEDs or other equipment in the room? Mask them and see if it makes a difference - if you can see the screen due to other illumination in the room when the pj is off then you may want to address that too.

    I personaly don't consider screendoor or scan lines to be an issue here though - if you have a well set-up system you shouldn't see either. Image artefacts are a pet hate of mine, and if I see something that shouldn't be there it takes me out of the movie. If you can see screen door (pixels) your screen is either too big or you're sitting too close. If you want to sit closer than 1.5 x screen width then DLP/LCD is a big no-no IMHO unless you want to defocus the lens. I can imagine scan lines are a set-up issue with CRT so an in-built line doubler (for example) or external scaler would probably do the job I would imagine (any input here from you guys would be appreciated - I'm here to learn!). Anything that that distracts you from the movie will probably have a similar effect, but if the contrast and depth is there the artefact is merely a distraction and hasn't actually reduced the CR/depth. The eye/brain is a very clever device so we're merely tricking it into seeing a 3dimensional image - you mention image clues and you may have hit the nail on the head.

    I also agree that having good resolution and contrast is only a part of the picture - good colour uniformity and accuracy play a big part too (D65 for example so skin tones remain accurate etc), along with geometry and image clarity/detail can all help to make an image more appealing but it must remain filmlike, and not too soft or too digital, either of which may look unnatural (of course they may be personal prefferences so deliberately produced). A good source is imperative of course. If you're only supplying half the detail it can't be created only duplicated/interpolated, so 1080/720 image lines will be sharing 576/480 for example. Detail is stored digitaly on a DVD so it has to be extracted and converted accurately in the chain to be displayed accurately. It's all links of a chain and not necessarily down to a single device - crap in, crap out (literally:) )

    Image optics are important and not many digital owners have that as a consideration - some lenses may lose focus towards the edges on whilst others remain sharp from corner to corner but not many bother to look - maybe it can't always be noticed from normal viewing distances but lens scatter is a factor for all lenses and that can. LC lenses on a CRT will reduce that component for CRT, and zooming the lens on a digital so the smallest image is being shone through through it will reduce it too - the bigger the light beam (image zoomed bigger), the more scatter that can take place, and it can be measured too - take full on/off readings with a light meter and it will be less with a zoomed (larger) image. Put a dodgy lens filter in place (Cokin gels for instance) and the same thing will happen very noticably with lens flare visibly bleeding from bright areas into dark areas (digital users should use coated lenses such as Hoya HMC btw). This has already been covered elswhere but it's another important part of image reproduction IMHO.

    Well, that's how I see it anyway. :)

    Gary
     
  3. crteaman

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    Nice to see a sensible and well thought out question answered in a sensible well thought out way, we need more of this and less bickering, its becoming a bit like 'big brother' :boring:

    Yes there are indeed a number of contributing factors but as Gary has said the main one is indeed contrast ratio,thats why the crt units look so good, not so much as raw light output,as we know, but bercause they achieve a much better black its actual contrast ratio is huge.

    When Barco looked at how fixed panel units were being measured (they sort of found other's were using DIN rather than WPC figures) they decided to measure the cine 9 in the very same way, it came out at over 30.000:1!!!.

    Yet we know a cine 9 simply does not have the raw light output of well, whatever many various models of lcd/dlp out there.

    For a truly involving and magical experience we need an image which is free of digital artifacts as possible, thus with a crt, seeing scan lines at our seated position simply will not do.
    The human eye need's to wander around the picture space as if looking at a fine painting, but if it see's a scan line the eye is not allowed to do this simple task,it will simply stop at many points as it picks up the scan lines (even though we may not be aware of this).

    Which is why, generally liquid coupled units have both better black's and a greater perceivable depth, because of the light being refracted back to the tube face on a non LC, which washes out those blacks and reducing the blacks,thus reducing contrast ratio and of course that means depth or less of it on non LC.

    We also need the picture to be very solid, for that we need to have a toatal lack of line structure, we need a very small beam spot size (read as sharp) to be able to drive a higher scan rate to get more lines without overlap (softening)

    Also don't forget the scaler guy's, this too has a big effect on the overall outcome,scaling is not a win win thing, its a lossy transition in deinterlacing, we just need to make sure we lose as little as possible when this transition happens, if you have looked at some of the older scaler's out there you will be nodding your head's to this one. (of course per pixel de-interlacing will help with this)

    Just as the crt has these issues it is also mirrored by the fixed panel units with their pixels, if the eye picks up on those,bang.. there goes the magic, and if the unit lights up the room whilst displaying a dark scene there goes the contrast....and depth.

    Those that have visited me, know my room is quite dark yet, because the is some stray light there is also light scatter/bounce because I do not have dark walls...ye gads! I have indeed got compromise in my system afterall, still it looks pretty good considering.

    So when are you popping down for a visit gary? it doesnt have to be a force crt down your throat situation, that's not what I tried to do at my event.

    We are all in the same great hobby, and will also find masses of other stuff to talk about.

    Since Pauliano (his 'd' also stands for don) has refered to me as the Don, thus quote "I'll make him an offer he cant refuse" :rotfl:

    james
     
  4. Voiceedit

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    This is a very interesting and informative thread. When my CRT proj (Sony VPH-D50QM) was installed I was amazed at the quality of the line-doubled image. I thoroughly agree with all the earlier comments about ambient light affecting the perceived result. One thing not yet mentioned though - masking. This, in my view, is of fundamental importance in maintaining an impressive image with good depth. In the cinema there is always an overthrow onto the masking, sometimes more than is necessary and sometimes not balanced either side, but this is because the edge of the projected image is blurred and it is unprofessional to display this to the audience. With CRT projectors (and probably LCD/DLP ones also) the edge of the projected image is much sharper and so the same problem does not arise.

    I place great emphasis when CRT projecting to ensure my masking is right up to the edge of the image, allowing about 2mm overthrow maximum. Warm-up time results in a gradual upward drift of the image so I have to allow for this at start-up (I can never wait the recommended time for achieving maximum picture quality!). My full screen is approximately 2.2:1 so that is used for DVDs from 70mm originals like The Sound of Music. I introduce a small amount of top horizontal masking and screen raising to present 2.35:1 CinemaScope DVDs (adjusted individually per DVD owing to variations in the positioning and size of the letter-boxed anamorphic image between DVDs). It's back to full screen height but with side masking added for 1.85:1 "Flat" DVDs and further side masking added for old films in 1.33:1 ratio, all done manually! It quite amazes me the number of home cinema installations I have read about in magazines which use a 1.85:1 maximum size screen; this therefore has to present a CinemaScope image in letterbox format. This is not cinema at all (apart from those in 1954 which found themselves with too narrow a proscenium to accommodate any extra width for the screen) - a smaller picture size for CinemaScope is just not on!
    Colin.
     
  5. Alan Westy

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    I think the reason that most CRT's are set up as 1.33 x 1 (4 x 3) or 1.85 x1 is to maximise the use of the phosphor on the tubes. The tubes of a crt are round so the maximum use of phosphor would need a 1 x 1 ratio. Using a 2.2 x 1 ratio means that approx only half the amount of the tube phosphor is activated compared to a 1.33 x 1 (4 x 3) picture. This obviously means driving the projector harder for a given light output and if you quite often view 1.85 x 1 or 4 x 3 material you are then using even less of the phosphor and are in fact viewing lettebox vertically.
     
  6. crteaman

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    Well said, masking/framing the Image also increases the perceived contrast ratio somewhat, this is where the veltex type of screen surround on fixed frames is wonderfull, killing any light overspill stone dead.

    Overscan really should be set at between 2.5-5% overscan, although with the advent of sdi on certain players we can almost get away with no overscan.

    The best way to set up for viewing all types of material (4:3 and 16:9 etc) is to have a 4:3 screen but have masking bars made up, bit of a bind moving them although well worth it for the duration of a movie.

    More Ideally would be the use of a multi masking screen, I would love one of these (I have a fixed frame) but, and here's actually admitting another compromise its the cost which put's me off at £5-£6000 pounds is crazy, but Its on my list of eventual upgrades.

    So pleased this thread moves along in a nice fashion, escaping the constant bickering and snipes elsewhere.

    james
     
  7. Godfather

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    Gary will be paying a visit to the real Don. :D
     
  8. Rob

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    Image depth is one of the things that CRTs can really deliver in spades. I remember seeing the beauty of japan HD tape when I went to view my 1609 in the workshop at Henry's. There is a part of the tape which focuses on america. It starts with a grand canyon fly over which has to be seen to be believed. The depth & texture of the rock is quite incredible, and this was at 1080i, no scaling (which I still use for HD). You almost felt like you were going to fall out of the helicopter.

    That sold it for me.I bought it on the spot and haven't looked back. :smashin:

    Cheers Rob.
     
  9. crteaman

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    Yes Henry never thought about you being quite close to gary, well done and nice of you to offer, have you worn those tubes out yet?

    Rob stop typing mate and get on with your room :D

    james
     
  10. Gary Lightfoot

    Gary Lightfoot
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    Great, and informative reading. :)

    James - how do the measuring methods differ? I use a full white field and full black field (0ire and 100ire) after calibration and setting white and black levels - I think this how WM does his too and it seems pretty much the standard as far as I can tell.

    I'm off to see the Don - he's made me an offer I couldn't refuse. :) Will confirm the day with him later.

    Digitals may be able to do a very bright image but I think this can also be a negative thing - it can highlight any image artefacts that may exist, such as mpg blocking or even artefacts of the projector itself. That's why I always ensure I'm getting around 12ft lamberts of reflectace from my screen. It's what you should get at cinemas but I've found anything from around 8 to 12 is OK. 4ft lamberts was surprisingly watchable as well :eek:. CRTs may be producing less lumens, but I've found that to be a good thing IMHO and I try to do the same. It produces a smoother more filmlike image. Some people like tv or plasma levels of reflectance (around 36ft lamberts IIRC), but I find that to produce a noisy looking image which is more like video than film, so that spoils the experience for me.

    Light decor in a room is more of a killer of ANSI contrast than full on/off. If you produce a bright image the light can bounce from the screen to the walls and back onto the screen, washing out the dark area detail, this is why ANSI can be very much a room dependant measurement, as well as a measure of what the lens is doing. If you're projecting black of course there's nothing to bounce of the walls so it doesn't effect the image.

    Hi Def does look stunning I have to agree. Someone mentioned a more 'solid' looking image and I totaly agree - I think mpg compression artefacts make an image look less solid and this has a negative impact on that part of the image. Dark areas can suffer from these and setting your black level correctly with a test disk is imperative IMHO (as is setting white levels). HD content seems to have a better compression so artefacts appear to be few and far between (the of-air recordings can have problems at times), and also appear to have more saturation. Demo HD stuff does this deliberately to further enhance the image at times I'm sure (Bikini Destinations anyone? :) ), but the extra detail, especialy in backgrounds helps to further improve the realism I suppose. I saw some Japanese Blu Ray on a large Plasma which I think was hi def because the detail was amazing. I would love to have known the resolution of the panel as the image was very impressive - it was outdoor scenes so no dark stuff which probably wouldn't have looked too good do to tha lack of CR to display it properly.

    I wonder if the extra detail from higher resolutions (the source and display - one will neuter the other) and higher contrast is giving the eye a better illusion of reality and making the image look more 3 dimensional? This will depend on viewing distance as well I would think - sitting too far back and the resolution becomes less resolvable by the human eye so to benefit from that resolution we need to be able to see it.

    I did read an article on the human eye and angles of arc etc so I'll have to dig that out again (if I can find it) and see what info that has about it.

    Gary.
     
  11. cosaw

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    Given available ceiling height this has got to be the most sensible solution. I'd prefer the look of a 16:9 screen but in the end I built the 4:3 and have bought some black flanalette material for manual masking of the main aspect ratios. Figure I might use velcro at the sides or in the future put the material on some sort of roller.

    Unfortunately my viewing room is large (in comparison to the screen size) and has all white walls. I was trying to think of a way of not having to fit black curtains to cover the whole area which would add an unwanted expense in material.

    I've got a specific viewing position which will accomadate about 3 people in width. I decided if I could control light reflection in the immediate area of the screen so that light reflection from the screen itself other than that towards the viewers eye or anything black is at minimum.

    So I'm going to try with my black flanalette (in addition to the masking) extending a box area from the screens top and sides in the style of horses blinkers. This would be most advantageous in a room (such as mine) where the size of the room is somewhat larger than the size of the screen. In this way reflected light from the screen is controlled mostly towards the viewer and the light pattern cast onto any walls is also squeezed smaller by the blinkers. I'd also back the black flanalette with some cheap blackout material I've got which would make them impermiable to light in both directions.

    Its an idea - not overly elegant perhaps but if its effective then thats what matters for me.

    Hope I've not gone too off topic.

    Simon
     
  12. Gary Lightfoot

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    Hi Simon,

    If you can't see it when a movie's on then it probably doesn't matter too much. :)

    Do you have a high gain screen? If the gain is high, that will help with unwanted reflections - screens with gain have a viewing cone, and this cone tends to be angular reflective (Da-Lite Hi Power is retro-reflective) so the light from the pj is bounced down (if ceiling mounted) more towards the seating area than the walls. Less light hitting the walls means less light reflecting back and reducing your ANSI (your blinkers should help a lot I would think). Screen gain is not a 100% cure but it does help and the effects can be measured. Grey screens with gain are probably the best at this and Optoma now do a 1.8 gain grey screen. I'm hoping someone will get some and measure it to see if the gain is accurate and if there is any colour shift (many screens have some colour colourshift, but Stewart Studiotec130 is one which doesn't and seems very accurate accurate for gain and colour)

    I'm currently experimenting with a cinemascope screen so that I have constant height and variable width. To do this I'm using an anamorphic lens with horizontal stretch and it works quite well. I just need to see if I need to do some variable side masking (like a so I can slide it out of the way like the curtains do in the cinema.
    You could probably do this with a CRT as well - there are DIY methods of making these lenses so you could make 3 of them on a common bar or MDF board, and have them hang underneath (if ceiling mounted) or over the top if coffee table mounted and then swing them into place when converting to 2.35:1. Sounds like an interesting project if someone wants to try it.

    Gary.
     
  13. cosaw

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    Hello Gary,

    Well its all done on a bit of a budget I'm affraid so in all honesty I probably can't expect much more than unity gain from Crown Brilliant White Emulsion - but whites do look good and bright and I beleive that if I can get blacks as black as poss then it should give good contrast. Hence my theories on light control - the blinkers will extend out a minimum of 1 m - perhaps more at ceiling level. On bright high contrast scenes say 50/50 pitch black and bright white the blacks are not as black as they could be due to light reflected back from the white walls - this is mainly where the blinkers should lend assitance.

    Regarding your cinemascope screen - Nice! My favourite aspect ratio. Before building my screen some time ago I posted on the forums about anamorphic lenses for crt pjs so I could use all tube area and get more light output whilst keeping a more favourable 4:3 wear pattern. Seems that these were never produced for crt probably because of the vertical squeeze capabilities of a crt pj. However you're saying there is such a thing as diy anamorphic lenses. Got any further pointers to material on this subject. It certainly interests me if good results are attainable - but at what price and effort would this be? I'm sure many crters would be interested in this sort of technology.

    Simon
     
  14. Gary Lightfoot

    Gary Lightfoot
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    Some good coats of matte white does a surprisingly good job of mimicking a lump of magnesium carbonate so isn't far from unity gain. It's when you want gain that you have to start trying to get samples or demos of materials as performance tends to vary, and it seems that depending on how the product is measured depends on what results you get (the gain varies for example).

    Ever thought of trying a fixed DIY screen? Can be as cheap as £25. Some Draper M1300 1.3 gain material can be bought from crtprojectors.com for a great price - just £19.95 per foot x 104" if you wanted to stretch it over your frame (scroll down):

    http://www.crtprojectors.co.uk/screens.htm :rolleyes:

    here's one link from an avs member for DIY lens:

    http://home.c2i.net/ahustvedt/lens.html

    Image quality will vary depending on the glass you use, but you could try cheap glass and silicon rubber till you get things right. I think that's how the guy above started out anyway.

    This hobby is all about compromises for many of us so we just have to do the best we can with what we have. Even so, I think we all still enjoy the end results of watching movies, and if we can tweak for a better image and get good results, that just adds to the fun. :)

    Gary.
     
  15. cosaw

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    Cheers for the links Gary - you'd certainly need a mighty big lens for crt and filled with water and oil probably quite heavy. Still Its worth toying with the idea if just for fun.

    Gary didn't understand your pricing on the home made Draper screen - you say £25 overall but the material is £19 per foot x 104". Does it stretch in one direction i.e. the direction where only 1 foot is available?

    My screen is a home made painted canvas 7ft wide 4:3 job - may think about different paints instead of the crown stuff. Just can't afford much else at the mo. Mind you if the Draper material stretches then perhaps I too could stretch to the extra £19. Wish I'd seen this before hand if so.

    Simon
     
  16. Rob

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    Yes, quite right. Been too busy finishing off peoples floors to spend much time doing my room :devil:

    Not too long now hopefully, once I get this screen problem sorted out that is :mad:

    Rob.
     
  17. Gary Lightfoot

    Gary Lightfoot
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    Sorry - I should have been clearer about the screen.

    For £25, you can do what you seem to have done already - made a frame and stretched/stapled blackout cloth (or canvas for painting) over it.

    The Draper material is priced by the foot but you will need about 6ft of it, so it will be £120. That's pretty good for real screen material but might be expensive depending on your budget. I might be trying it for my screen as currently I'm using blackout cloth as a test for the idea. It's collect only and I hate travelling. :)

    Gary.
     
  18. cosaw

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    Thanks for clearing that up Gary I guessed this was the alternative explanation. Worth keeping in mind that though for when I upgrade ;)

    Simon
     
  19. Vince M

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    Nice to see a sensible and well thought out question answered in a sensible well thought out way, we need more of this and less bickering, its becoming a bit like 'big brother'
    You`ll be applying for a Mods job next! :D :D



    Crt`s have better CR ,more accurate colours ,better optics-and I think this is a BIG factor in the reproduction chain-and IF no visible scan lines because of these things can present a clear window into the movie.

    DLP for example has better grey scale,better white field uniformity,less CR..far cheaper optics,but I believe EVEN if you still sit far enough back that you cannot see the pixels-they are there-like miniscule flecks in a clear plane of glass.
    All these pros/cons contribute to what you see,one could also argue that the less brightness from crt is actually a non fatiguing plus...as you can watch longer ..more relaxed and become more immersed in the experience.

    I actually asked Joel Silver about this yesterday,what his opinions were as it is well known he has a Runco DTV-1200(Cine 9)..he also has a dlp for casual viewing-all right for some eh? :smashin:

    It really comes down to the analogue/digital thing in a lot of respects..a lot of what creates that great "3d effect" is perceptory..an experience that is more suited to us humans.

    Like a piano tuner can train his ear..a videophile can train his eye and as such it could also be argued that those that setup/tweak regularly ,notice more and make subtle changes that help in that overall illusory experience...tough one though.. :rolleyes:
     
  20. Gordon @ Convergent AV

    Gordon @ Convergent AV
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    This is a good thread to I am going to post on the fixed pixel forum about some alternate thoughts on some of this.

    G
     
  21. yson

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    I agree with you Nick, differentiating depth thru variable focus, varying colour saturation and varying brightness. Those factors are achieve from having to reproduced the correct gamma for image reproduction and also maintaining the same voltage for 'black' image. Assuming you set up are perfect, the pj has high CR (ANSI/full-field), uniformity (color and brightness) are good and good focus system (like most high end Sony's CRT).... it is still possible to have a flat (2-D) images due to wrong gamma and fluctuating voltage for 'black'.
    Having the correct gamma will determine which part of the image should be defocus, color unsaturated, and so on.....

    Therefore having a high CR or low video noise are not enough to recreate a realistic image.
     
  22. crteaman

    crteaman
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    Hi Yson, Nice to see you here, how are those big nine inch beastie's coming along?

    james
     
  23. yson

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    I think Henry has made his point about me, did you know ?
     
  24. yson

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    But that's what we're trying to understand here, the process of that 3D perceptory and interpret that to the image we see at the screen. Moreover, how do we reproduce that image using electronics and optics.

    It shouldn't matter whether it's digital or analog, there is a way to reproduced the image depth.
    And i"m certainly confused how Joel Silver got to do with this thread ?
     
  25. Vince M

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    It shouldnt matter,but as Audiophiles we got used to that analogue sound and found digital "harsh"-maybe the same scenario with Video..

    "Like a piano tuner can train his ear..a videophile can train his eye"-Joel said this to me on the ISF course at Cambridge.
     
  26. Vince M

    Vince M
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    Guys,
    Ive posted some pics on the "what scenes look more 3d to you" thread..nothing special,but will give an idea of the fabled crt depth we talk of. :smashin:
     
  27. Gary Lightfoot

    Gary Lightfoot
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    Some very intersting comments here - definitely more too it than what we think. I wonder if it's really possible to quantify it technically so it can be easily reproduced though?

    Gary
     
  28. Vince M

    Vince M
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    No..thats the whole point ..its a total experience thing.. :boring: :boring:
     
  29. yson

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    It's nothing to do how the pj reproduced those images (digital or analog), if it can met those requirement that I posted and others obvious spec, like the CR, uniformity, no artifact, etc..... You can certainly reproduced images that was captured, quantification might quite difficult, but the explaination from the electronics or optics are possible.
    If the an image is captured with no image depth, then the pj will not reproduced the 3-D image. If this is a good pj in the first place.
     
  30. yson

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    If DLP, D-ILA / SXRD or CRT could meet those requirement, then it is possible to have image depth. Unfortunately, DLP, D-ILA or SXRD are still relatively young and still could be improve.
     

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