[TheFerret]

Yesterday, I found myself in Costco looking at a 50" plasma that I had been waiting on for a couple of months. They had it in a less than stellar viewing environment, playing a DVD with muted colors. So, what does this have to do with DLP? Well, as a norm, I have a very uncooperative saccadic masking condition which usually easily allows me to see DLP rainbows. On every front projection setup, to a varying degree, I can see rainbows without trying to look for them. Its bloody annoying, because it rules out DLP as a projection technology until 3xDMD becomes affordable to me.


Anyway, while standing there in Costco and right beside this 50" plasma is a 62" DLP RPTV. Its showing a different DVD that has strong colors (Finding Nemo) and I was impressed with the picture considering the material being shown and the environment. I kep looking back and forth between the plasma and the RPTV and then it struck me: where are the rainbows?


Ok, maybe my viewing angle isn't sufficient to provide a great-enough 'arc' for my eyes to sweep and catch the RGB separations. Maybe its the ambient lighting in combination with the DVD material to reduce or minimize the threshold of awareness of RBE, or is it something else? Ok, so I move closer to the 62". Now, I am standing maybe 6-7' and the screen-widths is on the order of

 

[MarcusInMD]

I was at a store the other day and saw rainbows on a DLP rear projections TV. But I really had to move my head back and forth. The room was well lit and the screen was only about 50" or so. I think the subject matter also had something to do with it. I only saw it when they went to a darker scene with some light objects.

 

[David F]

I have a CRT front projector and a Samsung 50" DLP RPTV. When I first got the Sammy I saw rainbows all the freakin' time. I've gotten acclimated to them to some degree, but it also depends on program material. You won't see them on something like "Finding Nemo," but you will when the overall scene is rather dark. Then they pop up like crazy around anything that is brighter than the darker background (think CSI nighttime scenes). I've been watching some of the "Law & Order: SVU" shows on UniversalHD and I see rainbows off and on pretty much through the whole show.

 

[Sharp1080]

Like everything else in life time tends to make us forget. When I first got my DLP front projector on a 120" screen I could see rainbows especially as noted with the dark/bright scenes. I personally just told myself stop darting your eyes back and forth looking for the problem? I was giving myself headaches! It doesn't even phase me now. If you specifically look for it you'll find it. I equate it to the Third eye 3d puzzles that are available. You have to really stare at it to see it?

 

[darinp2]

Ferret,


I don't know about the DLP you were looking at, but the literature for Samsung's new wobulated 1080p sets says they have 6x colorwheels (5x is the max I've seen for FP DLPs).


--Darin

 

[htpcfan]

Quote:

Originally Posted by Vern Sharp Like everything else in life time tends to make us forget. When I first got my DLP front projector on a 120" screen I could see rainbows especially as noted with the dark/bright scenes. I personally just told myself stop darting your eyes back and forth looking for the problem? I was giving myself headaches! It doesn't even phase me now. If you specifically look for it you'll find it. I equate it to the Third eye 3d puzzles that are available. You have to really stare at it to see it?

Well that is your explanation

I think you simply try to justify your initial decision for buying DLP.


I mean, by analogy, why not just watch VHS movies? Sure the quality is much less than DVD but just don't look for the problems just focus on the movie so you forget all the problems.


Frankly I am quite puzzled by all those videophiles who think they have critical eyes but seem not to be bothered by things like the rainbow effect or macroblocking enhancement.

 

[dragonbud0]

I see plenty of rainbows with a 2X PJ, but rarely see them in 4X or better. For DLP FP, I rarely see them but they're there and less annoying than 2X.


With Finding Nemo, I do see some during dark scenes, but not during the school scenes at the beinning and the end of the movie.

 

[ChrisWiggles]

Also, you were in costco, presumably with ungodly bright lighting. Second, finding nemo is all bright and colorful.


If you 1) brought something black with small white objects on it filmwise, like credits


and 2) convinced costco to turn off their lights for you


then i'll bet you'll see rainbows.


#2 may be more difficult. A large knife may not do it, because costco is really big. You may really need to threaten a serious hold up. A shotgun may suffice, unless your areas suffers from severe redneckitude syndrome, in which case you may need to threaten them with a singing plastic fish.

 

[TheFerret]

Darin, I actually don't even remember who made the set. Its not on their website, but the website seems to deviate somewhat from their retail stores. But you bring up a good point as I hadn't considered a wobulated unit. I just presemed it was a 720P DMD.

 

[ChrisWiggles]

OT: but JEEEBUS 8.5 thousand posts already wanman? Wow. You shouldn't take this as any kind of compliment .


anyway, I see the rainbows on the wobulated rptvs too, but I see rainbows everywhere, even on CRTs and plasmas. And gnomes.

 

[David F]

My Samsung RPTV is wobulated. I really like the smooth picture -- you can't see pixel structure at all, even from a few inches away -- but the rainbows make it tough for critical viewing. I watch all movies downstairs on the CRT big rig, but for HDTV sports, the Samsung is pretty sweet. I'm excited about Sony's 1080p SXRD sets not so much for the resolution -- though that is pretty damn cool -- but because they won't have any rainbows. The contrast ratio on the Samsung is very good, however; I don't know if the first gen SXRDs will hold up as well.


Trade-offs and compromises everywhere you turn....

 

[Carled]

I don't see rainbows (well, I haven't yet at least) with 5x and 6x colour wheels.


They still give me a bad headache though.


If you don't see rainbows, and don't get headaches at a given wheel speed, then you're probably all clear.

 

[TheFerret]

I hope none of you thought I was just trying for another RBE thread. I was just wondering if there was something in the projection system of an RPTV that provided a condition quite different form front projection using the same DMD engine. I'll have to find out what specific RPTV I happen to be looking at and determine from there the TI guts.


It really has been almost a couple of years since I've seen a 720P DLP projector.

 

[ChrisWiggles]

Quote:

I was just wondering if there was something in the projection system of an RPTV that provided a condition quite different form front projection using the same DMD engine.

No, which is why I mentioned that it's likely just the bright lighting environment which isn't possible with a FP setup, but you can stick an RPTV on a bright displayroom floor, and/or the material you were watching. I.e. it's not surprising that you didn't see rainbows in such an environment, however, I wager you immediately would if you moved the display to a darkened room, and played material that would elicit better "rainbow response" as it were...

 

[pheroy]

My experience with DLP RPTVs is that in 2004 and before, I had little trouble seeing rainbows on them. That was primarily with Samsung models, as the DLP bandwagon had yet to fill up with other brands the way it has in the last year. Early this year (or late last year) however, I viewed some of the newer generation DLP RPTVs from Samsung, LG, Toshiba and I think Panasonic... and noticed that I had a very difficult time seeing rainbows. There has definitely been some kind of upgrade -- perhaps the 6x wheels, perhaps other things too -- in the current generation with respect to color separation artifacts. Of course, I'm not bothered to distraction by them as I have a 2x DLP FP in my setup. (I can see 'em, just trained myself to watch without provoking them. Not that I'm not looking at various upgrades, and would love to not worry about them at all!)


If you can find a Samsung HLN or HLM series to view, you might be able to compare to the current models. For me, the recent ones seem to have surpassed a threshold.

 

[Joseph Clark]

Quote:

Originally Posted by htpcfan Frankly I am quite puzzled by all those videophiles who think they have critical eyes but seem not to be bothered by things like the rainbow effect or macroblocking enhancement.

I think that's a simplification of what happens over time with RBE. I'll relate a telling RBE story. With the first generation of DLP projectors, I couldn't watch without severe discomfort with RBE. Then I saw a Sharp 9000 with the higher speed color wheel. I still saw RBE but it was a dramatically improved experience. I bought it.


That Sharp had to go in for repair and I was without it for about a month. I walked into Best Buy one day and, without having seen them for a long time, I saw RBE on every RPTV DLP there. I got the set back and within a few days I was once again having trouble seeing RBE, even if I tried.


I just upgraded a couple of weeks ago to an Optoma H79, which has dramatically improved contrast ratio, and much better intraframe contrast. The RBE was back and in a big way. Based on the experience with the Sharp, I wasn't worried too much. Now, I'm having trouble seeing them on the Optoma, too.


Equating that with lack of sensitivity to macroblocking enhancement (you mean macroblocking and edge enhancement, don't you?) is misleading. I've never lost sensitivity to those picture flaws and I don't consider my brain's ability to adjust to RBE in the same "Shallow Hal" realm.


I love DLP and even though I could see RBE so easily that it scared me away from the first generation, I think it's a bit of a disservice to make too big a deal of it. Some people, I think, may be driven away from this technology if they learn how to look for RBE and then believe that knowing how to perceive it will mean that the effect will become worse over time. I believe that for most the opposite is likely to be the case. The brain will "tune" the effect out.


Certainly, this is not the case for everyone. I know that some people get headaches from the technology. That's been documented here many times. The best way to find out if you are susceptible is to try it. Take several DVD's with you to a dealer who'll let you watch, and try it out for an hour. Take some high contrast scenes and try to find rainbows. If you have trouble at first and it gets better, my guess is that it will improve to the point that it is not an issue.


No amount of my brain's ability to fool me has ever made me see HD where there was only SD, nor mistake bright outlines around edges for picture detail. I put tunig out RBE in the same category as my brain's ability to see a 3D image in a stereogram on screen. In fact, with single chip DLP, all that's ever up on the screen at any given point in time is a red or a green or a blue image, but like the illusion of the 3D stereogram, it sure looks like a lot more than that.


Rich color, wonderful contrast, deep blacks, sharp detail and not a hint of misconvergence - that's what DLP is to me. There may be a good bit of optical illusion in this, but there isn't much in the way of delusion.

 

[rogo]

Ferret, I see rainbows on every single DLP RPTV on the market when I walk into a store that has them. So, no, it's not different than FP.


David F, the Sony's are slated to have a dynamic iris, so they might be quite good in CR.

 

[David F]

Rogo, that's right, I forgot about the iris. Though I have heard both good and bad about them (namely, that on some program material the apparent brightness of the picture will vary noticeably). Of course, I'd want to check that out for myself.

 

[MikeSer]

It is not necessary to move your head madly or "dart your eyes" to see RBEs.

Being a sensitive guy , I can see RBEs in dark, high-contrast scenes (e.g., in "Daredevil") if I BLINK.

I've "trained myself" not to blink when watching such scenes...


Mike

 

[TheFerret]

Ok, maybe its just an anomaly. I'm going back to that store on Wednesday, while on the way into the workplace. I'll have a second look, but mostly at the plasma I went to look at on Saturday.