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HDTV - LCD projection vs. DLP - the red problem

Last response: in Home Theatre
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February 1, 2005 12:59:51 AM

Archived from groups: alt.tv.tech.hdtv,rec.video,rec.arts.tv (More info?)

Hello,

Up until yesterday, I was looking into purchasing a LCD projection
HDTV set (most likely a Sony) until an apparently knowledgeable
salesman at a video store pointed out the weakness of the red colors
in the LCD projection vs.the DLP competition.

Nevermind the other issues of contrast, black, brightness, etc.
between these two technologies - this was something I had no idea
about until I saw it with my own eyes.

Unfortunately, the LCD proj. reds were a bit orangish than true reds
when compared to the DLPs. According to the salesman, this was an
inherent problem with the LCD projection sets and tweaking the red on
the controls did not compensate since that ended up affecting the
other colors.

Anybody out there know about this and care to comment?

This has certainly steered me back towards DLPs at this moment...

TIA,

Jack
Anonymous
February 1, 2005 12:59:52 AM

Archived from groups: alt.tv.tech.hdtv,rec.video,rec.arts.tv (More info?)

Always listen to "knowledgeable" salesmen. Stick to DLP and enjoy the
rainbow.

"Jack" <sacjack66@removehotmail.com> wrote in message
news:ko9tv09o1dng6pf9426mecumvgkijojadt@4ax.com...
> Hello,
>
> Up until yesterday, I was looking into purchasing a LCD projection
> HDTV set (most likely a Sony) until an apparently knowledgeable
> salesman at a video store pointed out the weakness of the red colors
> in the LCD projection vs.the DLP competition.
>
> Nevermind the other issues of contrast, black, brightness, etc.
> between these two technologies - this was something I had no idea
> about until I saw it with my own eyes.
>
> Unfortunately, the LCD proj. reds were a bit orangish than true reds
> when compared to the DLPs. According to the salesman, this was an
> inherent problem with the LCD projection sets and tweaking the red on
> the controls did not compensate since that ended up affecting the
> other colors.
>
> Anybody out there know about this and care to comment?
>
> This has certainly steered me back towards DLPs at this moment...
>
> TIA,
>
> Jack
>
>
>
Anonymous
February 1, 2005 2:03:38 AM

Archived from groups: alt.tv.tech.hdtv,rec.video,rec.arts.tv (More info?)

LCD *and* DLP projectors tend to use Ultra High Pressure Mercury Vapor
lamps, which are *weak in red* relative to green and blue. It is a constant
challenge for LCD *and* DLP projector manufacturers to display balanced
color. This is not a DLP vs. LCD issue. Both camps ship projectors that are
bright but underpowered on red, or not as bright and balanced across RGB.

Thomas Gilg

"Jack" <sacjack66@removehotmail.com> wrote in message
news:ko9tv09o1dng6pf9426mecumvgkijojadt@4ax.com...
> Hello,
>
> Up until yesterday, I was looking into purchasing a LCD projection
> HDTV set (most likely a Sony) until an apparently knowledgeable
> salesman at a video store pointed out the weakness of the red colors
> in the LCD projection vs.the DLP competition.
>
> Nevermind the other issues of contrast, black, brightness, etc.
> between these two technologies - this was something I had no idea
> about until I saw it with my own eyes.
>
> Unfortunately, the LCD proj. reds were a bit orangish than true reds
> when compared to the DLPs. According to the salesman, this was an
> inherent problem with the LCD projection sets and tweaking the red on
> the controls did not compensate since that ended up affecting the
> other colors.
>
> Anybody out there know about this and care to comment?
>
> This has certainly steered me back towards DLPs at this moment...
>
> TIA,
>
> Jack
>
>
>
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February 1, 2005 2:03:39 AM

Archived from groups: alt.tv.tech.hdtv,rec.video,rec.arts.tv (More info?)

<thomasDELME_gilgDELME@hpDELME.com> wrote in message
news:ePyLd.6958$WD3.3587@news.cpqcorp.net...
>
> LCD *and* DLP projectors tend to use Ultra High Pressure Mercury Vapor
> lamps, which are *weak in red* relative to green and blue. It is a
constant
> challenge for LCD *and* DLP projector manufacturers to display balanced
> color. This is not a DLP vs. LCD issue. Both camps ship projectors that
are
> bright but underpowered on red, or not as bright and balanced across RGB.
>
> Thomas Gilg
>

Is that why the colour wheel used with DLP technology has now adopted a
fourth colour of green?
Take Care
Tec
Anonymous
February 1, 2005 9:24:05 AM

Archived from groups: alt.tv.tech.hdtv,rec.video,rec.arts.tv (More info?)

"Jack" <sacjack66@removehotmail.com> wrote in message
news:ko9tv09o1dng6pf9426mecumvgkijojadt@4ax.com...
> Hello,
>
> Up until yesterday, I was looking into purchasing a LCD projection
> HDTV set (most likely a Sony) until an apparently knowledgeable
> salesman at a video store pointed out the weakness of the red colors
> in the LCD projection vs.the DLP competition.
>
> Nevermind the other issues of contrast, black, brightness, etc.
> between these two technologies - this was something I had no idea
> about until I saw it with my own eyes.
>
> Unfortunately, the LCD proj. reds were a bit orangish than true reds
> when compared to the DLPs. According to the salesman, this was an
> inherent problem with the LCD projection sets and tweaking the red on
> the controls did not compensate since that ended up affecting the
> other colors.
>
> Anybody out there know about this and care to comment?
>
> This has certainly steered me back towards DLPs at this moment...
>
The lamp that ALL projection (DLP and LCD) TV's use is a High pressure
mercury vapor lamp. This light has very little Infra red and less Red than
normal light. I would expect that filtering technologies, LCD and DLP (uses
a color wheel filter) can't give back what is missing.

I have personally not seen a difference in the reds from DLP to LCD
projection TV. Both technologies give very good pictures. The only
criticism I have is the lowered pixel count vs. regular projection TV. You
have to balance that out against perfect registration and focus.
Anonymous
February 1, 2005 11:01:36 PM

Archived from groups: alt.tv.tech.hdtv,rec.video,rec.arts.tv (More info?)

Tecumseh wrote:
> Is that why the colour wheel used with DLP technology has now adopted a
> fourth colour of green?

Mostly no.

The colorwheel is 360 degrees of filter glass carved into 3 or more
segments, with red, green, blue and white being the most common.
Note that white can pass 100% of the bulbs energy, while the color
segments only pass ~33% of the bulbs energy. In a business projector
that wants to optimize brightness over color, a 90 degree white segment
(1/4th of 360) will actually account for 50% of the projector's total lumen
rating (1/2), with a noticable impact on color accuracy and saturation.

For home-theater projectors, the white segment is the first to go, hence a
huge drop in potential lumen output. Big problem.

The next problem is that getting the R-G-B balance right means creating a
huge R segment at the expense of G and B, hence another big drop in total
lumen output. Time spent milking red out of the bulb means time not spent
tossing more abundant G and B lumens on the screen.

The red problem is basically solved by sacraficing lots of lumens.

The use of secondary color segments has less to do with addressing the red
problem and more to do with fine tuning colors and ramps. InkJet printers
used
to be CMY, but now CMY + 1-3 CMY variants are now common. Better color.

Thomas Gilg
Anonymous
February 3, 2005 10:03:54 PM

Archived from groups: alt.tv.tech.hdtv,rec.video,rec.arts.tv (More info?)

Or stick with the LCD and enjoy the screendoor.

Don

"lotus" <tohuva@bohu.com> wrote in message
news:eOyLd.41564$Rw4.834628@weber.videotron.net...
> Always listen to "knowledgeable" salesmen. Stick to DLP and enjoy the
> rainbow.
>
> "Jack" <sacjack66@removehotmail.com> wrote in message
> news:ko9tv09o1dng6pf9426mecumvgkijojadt@4ax.com...
>> Hello,
>>
>> Up until yesterday, I was looking into purchasing a LCD projection
>> HDTV set (most likely a Sony) until an apparently knowledgeable
>> salesman at a video store pointed out the weakness of the red colors
>> in the LCD projection vs.the DLP competition.
>>
>> Nevermind the other issues of contrast, black, brightness, etc.
>> between these two technologies - this was something I had no idea
>> about until I saw it with my own eyes.
>>
>> Unfortunately, the LCD proj. reds were a bit orangish than true reds
>> when compared to the DLPs. According to the salesman, this was an
>> inherent problem with the LCD projection sets and tweaking the red on
>> the controls did not compensate since that ended up affecting the
>> other colors.
>>
>> Anybody out there know about this and care to comment?
>>
>> This has certainly steered me back towards DLPs at this moment...
>>
>> TIA,
>>
>> Jack
>>
>>
>>
>
>
Anonymous
February 3, 2005 11:25:14 PM

Archived from groups: alt.tv.tech.hdtv,rec.video,rec.arts.tv (More info?)

I can see it really, with a magnifier 1/2 inch from the screen.

"M-Tech" <mechtechllc@yahoo.com> wrote in message
news:3PidnZs1P5BxJp_fRVn-hA@comcast.com...
> Or stick with the LCD and enjoy the screendoor.
>
> Don
>
> "lotus" <tohuva@bohu.com> wrote in message
> news:eOyLd.41564$Rw4.834628@weber.videotron.net...
>> Always listen to "knowledgeable" salesmen. Stick to DLP and enjoy the
>> rainbow.
>>
>> "Jack" <sacjack66@removehotmail.com> wrote in message
>> news:ko9tv09o1dng6pf9426mecumvgkijojadt@4ax.com...
>>> Hello,
>>>
>>> Up until yesterday, I was looking into purchasing a LCD projection
>>> HDTV set (most likely a Sony) until an apparently knowledgeable
>>> salesman at a video store pointed out the weakness of the red colors
>>> in the LCD projection vs.the DLP competition.
>>>
>>> Nevermind the other issues of contrast, black, brightness, etc.
>>> between these two technologies - this was something I had no idea
>>> about until I saw it with my own eyes.
>>>
>>> Unfortunately, the LCD proj. reds were a bit orangish than true reds
>>> when compared to the DLPs. According to the salesman, this was an
>>> inherent problem with the LCD projection sets and tweaking the red on
>>> the controls did not compensate since that ended up affecting the
>>> other colors.
>>>
>>> Anybody out there know about this and care to comment?
>>>
>>> This has certainly steered me back towards DLPs at this moment...
>>>
>>> TIA,
>>>
>>> Jack
>>>
>>>
>>>
>>
>>
>
>
!