Passive vs Active 3D TVs, revisited

In my post ‘Sorry, but it is half vertical resolution‘ I claimed that my tests support the view that passive 3D TVs, with current technology, provide only half the vertical resolution of active ones. I made reference therein to an excellent and detailed article, ‘3D TV Display Technology Shoot-Out‘, by Dr. Raymond M. Soneira, President, DisplayMate Technologies Corporation in the US, but disagreed with one aspect of it.

Dr Soneira has kindly responded to my email.

Before getting to that, I shall summarise. By my reading Dr Soneira’s article seemed to suggest that passive 3D TVs effectively produced full vertical resolution because the human eye/brain mechanism can knit together the half resolution content delivered to each eye into a full resolution picture. I disagreed because for this to be true, then the left and right eyes would have to receive different scan lines: say all the odd ones for the left eye, all the even ones for the right eye. But my tests suggest that they both receive the same scan lines in 3D mode: odd for both eyes or even for both eyes. My blog post explains my reason for thinking this.

Here’s Dr Soneira’s response:

First of all, I didn’t make any assumptions. I used an extensive series of specialized test patterns to examine the vertical resolution issues in detail.

Second of all, my article has been thoroughly examined by a very large number of top display experts, including the engineering departments of LG and Samsung. No one has found any technical flaws. While Samsung does not like my results, my 3D article was used as the central technical exhibit in an extensive 4 month investigation with extensive expert testimony by many display experts in an arbitration battle on this 3D half resolution issue between LG and Samsung in the USA. The ruling was against Samsung’s claims of half resolution – and my 3D article was the central technical exhibit that convinced the NAD to rule for LG and against Samsung’s half resolution claims, which were thrown out as without technical merit by the NAD. As a result of this arbitration decision Samsung has agreed to end those claims in the USA, although they disagree with the conclusions of the NAD.

The above is the best explanation as to why my 3D article doesn’t have errors – Samsung couldn’t convince an independent arbitration organization, and the NAD ruled that my article conclusions were valid.

Here are links to the Press Release Announcing the decision:
NAD RECOMMENDS SAMSUNG DISCONTINUE CERTAIN SUPERIORITY CLAIMS FOR 3D TELEVISION
NAD Press Release: http://www.narcpartners.org/DocView.aspx?DocumentID=9039&DocType=1
NAD website with Press Releases: http://www.nadreview.org/

First, I must apologise. I did use ‘assumptions’ as a sloppy shorthand in my email to him. In fact, his article is highly detailed and thoroughly researched. Which is why I find it so intriguing that our results differ on this point.

As to the other matters, they do not address my contrary findings. The next time I have a passive 3D TV to hand, I shall create some special test patterns to determine unambiguously whether in 3D mode such TVs deliver the same scan lines to each eye, or alternate ones.

As for the NAD’s findings, I’ve addressed this in some detail in the previous post and, at least as far as the press release goes, the ruling did not seem to be definitely ‘against Samsung’s claims of half resolution’. It seemed to be against Samsung making those claims of half resolution because it would give the impression that passive 3D tech was inferior, overall, than active 3D tech.

At this point, I should note that I am open here to a complaint of too closely examining the text of the press release. Can I just say that I’m pretty good at bureaucratese and legalese, having worked in relevant areas for a number of years. Words in these things are usually chosen very carefully, so they have to be read very closely if you are to understand them. Nonetheless, my understanding here is preliminary. I have asked NAD for a full copy of their findings which will allow me to get a better understanding.

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5 Responses to Passive vs Active 3D TVs, revisited

  1. Craig Mecak says:

    Hi Stephen,

    I’m inclined to side with you on this one.

    Also, did Dr. Soneira’s article indicate whether his tests were done on 50Hz or 59.94Hz Video-originated 3D, such as Sport? Where every video field is meant to be different, ie a different point in time; 50 or 60 unique images per second (per eye)? Or is it only referring to still test patterns, or the low-ish frame rate of feature 3D content, ie 24Hz, where you *MIGHT* be able to get away with one even-line 540p frame for one eye, and one odd-line 540p frame for the other? Presuming it is done correctly, as you point out.

    Craig.

  2. Craig, I got the impression he was using 24fps content. Looking at the actual decision, it seems that he had some impressive people lined up against him, including Joe Kane.

  3. Ryan Sandford says:

    I just want to say am glad to have contribruted to this debate. Despite my previous rudeness… There is so much myth and conjecture on this subject all over the net with little detailed scientific information, so its wonderful that two clear experts are in touch and debate on this subject. I look forward to the resoloution (pardon the poor pun). Did you get to read Sten De Witts take on his blog yet? – http://stijndewitt.wordpress.com/2012/03/03/active-vs-passive-3d-myth-revisited/ .

    I am sure this also adds some pertinent information. Thanks again and keep up the great work.

  4. Donald_S says:

    Presumably the LG R&D department should be able to clarify the question of “all odd” or “all even”, or “odd for left” and “even for right” (or “even for left” and “odd for right”).

    So many permutations. My head hurts! 😀

  5. It has been years since I’ve put a technical question to one of the large TV manufacturers. I gave up around the time I couldn’t even get my message across about some easily fixed flaw in picture processing. I don’t recall, off hand, of ever getting a truly satisfactory answer. Part of it is language. Part is having to negotiate the PR barrier. Part is defensiveness.

    And then, even if I do get an answer, I still have to double check to confirm it.

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