[Waingro]

Hi guys,


Have been a voyeur on these threads for far too long, I thought it time I participated.


Interested to here from those in the know about these 5 segment, 2 times colour wheels that are appearing, in particular on new units , the NECs HT410 and HT510 + the new Benq cheapie, the PE5120.


Benq use 4 segment, 3 times on their data projectors 6100 and 6200.

Now with the new PE5120 they are going 5 segment, throwing in a yellow segment but keeping the speed down at 2 times.


The obvious question is how does the combination of 5 and 2 go with the dreaded "rainbow effect". My understanding is that increasing the speed to 3 x reduces the effect just that little bit more, to the point that for most people it reduces all rainbow problems.


Why then on specific Home Theatre designed projectors of which these three are touted, are we slipping back to 2x speeds ?


I have read the other threads on this subject including the Benq PDF

brochure, but it still doesn't answer all of my queries.


Please explain . Slightly confused.


Regards,

Waingro

 

[guitarman]

To new to know yet. First reports are the colors are natural and more suited for HT. Rainbows! we'll need some head shakers to test it out.

 

[MHoefler]

I tested a BenQ 6210 (see my thread) which is supposed to have a 4x speed, 4 segment wheel. The rainbows were exactly the same as on 2x speed units! I actually doubt it has a 4x wheel after seeing this, and even the 3x wheel it probably has, doesn't really change rainbows.


Regards, Martin.

 

[thatdreamer]

Well, a yellow segment is theoretically equivalent to another red/green refresh every cycle. So maybe you could call it 1 2/3 refreshes per cycle. So a 2x wheel like this COULD be considered a 3 1/3 x wheel. Whether or not this really works for reducing rainbows has yet to be seen, but even 3x wheels are often a problem for people who are sensitive to rainbows. So don't expect miracles.


I like the idea of a yellow segment. Most projector lamps are deficient in red and green, so a yellow segment should allow for more efficient use of the bulb's output. Of course a superior method would be to make the red and green segments longer . . .

 

[SMP01]

The refresh cycle is supposed to be the number of times a single color gets refreshed. 2x implies the red gets refreshed twice per cycle. I believe a cycle = 30 times/second.


So if red is in the color wheel twice (as in RGBRGB 6 sement wheel) and it spins at 60htz (2x), then red passes the light path at a rate of 4x, 2 sections of red x double wheel speed. A 5x refresh rate is usually a 6 segment wheel spinning at 2.5x


I'm still not sure what the yellow will do and the original question is a good one.

 

[mliu92]

My understanding [based on the BenQ PowerPoint PDF] is that the clear ("white") segment is turned off in eco-mode, effectively making the projector a 4-segment (RGBY), 2x machine & dropping the brightness level. Some people say that for a given wheel speed, a lower-brightness machine will exhibit less RBE. The 5s wheel makes sense on paper -- turn the clear segment on for higher brightness (helps with ambient light, which kills color saturation anyway), turn it off for better color saturation when you don't need the brightness.


A yellow segment makes some sense when you consider the spectrum from the UHP bulbs in most projectors -- somewhat deficient in red & green (note that the red segments on the SP4805 wheel are both longer than the blue & green segments). When you combine red & green light, you get yellow. Thus, theoretically, you can boost both red & green saturation with the yellow segment.


As everyone says, though, the proof is in the pudding. Based on the shipping dates, the HT410 should already be reaching its first consumers ... but there's no reports yet, aside from a few mentions at CEDIA.


By the way, if the BenQ streets anywhere near its MSRP of US$2295 when it's available in November 04, it's going to face an uphill battle against the SP4805 (6s, 4x) and HT410 (lens shift), both of which would offer some compelling features at lower MSRP. I'm going by the MSRP announced on BenQ's website, on their product guide.


Links to follow ... my post #5 ...

 

[mliu92]

 BenQ PowerPoint PDF , originally explaining the 5s technology.

NASA color calculator , tax dollars at work showing that red + green = yellow.

A few mentions at CEDIA regarding the new NECs.


BenQ's US PDF product guide showing MSRP on all products.

 

[Bidda]

Quote:

Originally posted by mliu92 .....By the way, if the BenQ streets anywhere near its MSRP of US$2295 when it's available in November 04, it's going to face an uphill battle against the SP4805 (6s, 4x) and HT410 (lens shift), both of which would offer some compelling features at lower MSRP. I'm going by the MSRP announced on BenQ's website, on their product guide.

I have read (somevere) that the price was going to be $999 5120 i have ordred here in Norway will cost me 9990 NOK (= $1500) That inkl shipping and taxes.

 

[timctx]

Wonder is it would be possible to change the white segment on my X1 to yellow or if that would screw up the synching.

 

[darinp2]

Quote:

Originally posted by timctx Wonder is it would be possible to change the white segment on my X1 to yellow

The projector would then put out yellow when it is trying to put out white.


--Darin

 

[Chrismo]

I have my doubts that the 6200 actually is a 3x wheel. If it is, then why won't Benq confirm it. Only Proj. Central seem to have this info.


I emailed Benq with this question, and they didn't answer it. They just said, "don't get to hung up on segments to wheel etc".


I suspect that it's actually a 2x, and so the 5120 has the same speed wheel with an extra segment.


I bet the 3x myth (if thats what it is) has sold a lot of PJ's.


I'm happy to be proved wrong.

 

[Waingro]

Chris,


On taking a second look at the Benq PDF that explains the 5 segment technology, there is a spreadsheet half way through that shows the various projectors in the PE range, the various styles and speeds of wheel.


On the far left it has a broad brush column that just says Data Projectors

and has a piccie of a Benq 7XXX. It states clearly there that the colour wheel is spinning at 2x Colour Wheel Speed (120hz) and Refresh Rate

2x (120hz)


So that I will assume confirms that the 6200, a data projector, would have to be a 2 x and not a 3x as stated by Proj/Cent.


This right or am I barking up the wrong tree.


Waingro

 

[Chrismo]

I've seen the PDF and I wondered why Benq would miss such vital sales pitch as the 3x wheel.


I think it's safe to say the 6100/6200 is 2x until someone from Benq corrects us.

 

[metablob]

Nope bad assumption, the Benqs have a 3x wheel - the marketing guys have it wrong - it's been known to happen. If you can see raibows and have seen a 2x unit versus a 3x unit, you will see the difference. In fact I would even question that the 5120 would have a 2x wheel on that basis. Obviously whoever put together the PDF has their facts screwed up. Until it shows up and someone can review it I would not make a buying decision based on this "information".

 

[Killefitt]

I asked Benq a question about my 6100 about the color wheel speed trying to find out which refresh rate should theoretically produce less rainbows, I had read some posts about the X1 changing speeds, and they confirmed by e-mail that mine does not change speeds, runs at a steady 3x speed, which probably means it only displays 60hz as well.


Kille

 

[Mardelgo]

I saw the Benq 6200, (I was very interested in this unit) but I saw exactly the same amount of rainbow effect that I see in my 2x speed unit, then I saw the Infocus SP4805 and in this unit almost didn’t saw rainbows. I don’t think the benq has 3x speed, and if it has doesn’t help at all.

 

[metablob]

Source material does have a direct influence on the ability to see rainbows - at least in my case. Bright, colorful source material - amination (Shrek for example) masks the effect, while dark, low color material (some DVDs) will enhance them. If you didn't watch the same source material on all the projectors, then your comparison won't yield you much valid information. I suggest bringing your own DVD to the showrooms.

 

[SpeedyHTPC]

Quote:

Originally posted by Waingro Hi guys, Have been a voyeur on these threads for far too long, I thought it time I participated.

Definition

voyeur [Show phonetics]

noun [C] DISAPPROVING

a person who gets sexual pleasure from secretly watching other people in sexual situations, or (more generally) a person who watches other people's private lives:


ohmy

 

[ddog]

I guess he used the wrong work.


What ya think Webster!


Ddog!!

 

[Mardelgo]

Metablob:

I did saw the same movie(Gladiator). Don’t get me wrong. I think that the 6200 is a great machine, it has excellent contrast, colors and resolution (you can really see the extra resolution than in the SP4805), but in the rainbows aspect, that I think is what we here are a little skeptical with the 5120, is in what I saw no difference with a 2x unit, and I can really saw in the 4805. I just trying to share what I saw, so if some one is trying to avoid the rainbow effect, (what by the way I don’t think as much as a problem, for me lack of contrast, resolution, and brightness of a image is more important), I don’t think that a 3x wheel DLP is enough.