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geekhack Community => Off Topic => Topic started by: Manyak on Fri, 10 December 2010, 17:52:47

Title: I <3 morons
Post by: Manyak on Fri, 10 December 2010, 17:52:47

Quote from: Mayniyak

This right here (http://www.anandtech.com/show/3946/apple-27inch-led-cinema-display-review/1) is the most in-depth review on the new 27" Apple display that I know of, and compares it to the 30" one and many other higher end monitors. Skip to the conclusion if it gets too technical for you.

Put simply: It's a decent display, but it's only middle of the road compared to other displays in it's price range. The Dell U2711 uses the same LCD panel but opts for a CCFL backlight: which gives you a wider gamut, better contrast, and a more accurate white point.

Quote from: Saint728

The Apple 27" Cinema Display is an LED not LCD. It also has a backlighting system which gives you a 178˚degree viewable area.

Take Care,
Cheers, Patrick

:frusty:

Title: I <3 morons
Post by: microsoft windows on Fri, 10 December 2010, 17:54:24

If only he said "It's an LED display, not an LCD display" it would've been even better...

Title: I <3 morons
Post by: Manyak on Fri, 10 December 2010, 17:59:18

Quote from: microsoft windows;260999

If only he said "It's an LED display, not an LCD display" it would've been even better...

but that IS what he said..

Title: I <3 morons
Post by: PAINKILLER on Fri, 10 December 2010, 18:00:38

Nah, that's how someone with RAS Syndrome (http://en.wikipedia.org/wiki/RAS_syndrome) would say it. You see, LED stands for Light Emitting Display, so it already has the word "display" in it.

Title: I <3 morons
Post by: microsoft windows on Fri, 10 December 2010, 18:00:48

Liquid Crystal Display Display...

You know, the LCD display on your GPS system?

Title: I <3 morons
Post by: Manyak on Fri, 10 December 2010, 18:02:26

Quote from: microsoft windows;261004

Liquid Crystal Display Display...

You know, the LCD display on your GPS system?

And on the ATM machine.

Title: I <3 morons
Post by: PAINKILLER on Fri, 10 December 2010, 18:03:16

Quote from: microsoft windows;261004

the LCD display on your GPS system?

"GPS system" is OK in this case, because it means the appliance, not the whole system with the satellites etc.

Title: I <3 morons
Post by: microsoft windows on Fri, 10 December 2010, 18:04:01

Global Positioning System System?

Title: I <3 morons
Post by: PAINKILLER on Fri, 10 December 2010, 18:04:49

Yes, a system within a system.

Title: I <3 morons
Post by: isp on Fri, 10 December 2010, 18:05:04

Good review.  It's probably not the best choice for most people, but it's pretty much the only option for those that work in dark environments and hate the sparkle/shimmer effect produced by LG's overly-aggressive antiglare coating.  

I've been hoping that NEC would produce a bigger brother version of the 20wmgx2 but I'm not holding my breath. meh

Title: I <3 morons
Post by: Lanx on Fri, 10 December 2010, 18:10:14

Quote from: PAINKILLER;261002

Nah, that's how someone with RAS Syndrome (http://en.wikipedia.org/wiki/RAS_syndrome) would say it. You see, LED stands for Light Emitting Display, so it already has the word "display" in it.

I need a (S.olid S.tate D.rive) hard drive. Or should i get 2 and have it in a (R.edundant A.rray I.nexpensive D.isk) arry? But i should probably upgrade from 4gigs of (R.andom A.ccess M.emory) memory to 8 gigs of RAM memory first, though i don't know if I instead need to upgrade my dual-core (C.entral P.rocessing U.nit) processor first?

I guess RAS is in everything computer related.

Title: I <3 morons
Post by: CodeChef on Fri, 10 December 2010, 19:08:59

Quote from: PAINKILLER;261002

Nah, that's how someone with RAS Syndrome (http://en.wikipedia.org/wiki/RAS_syndrome) would say it. You see, LED stands for Light Emitting Display, so it already has the word "display" in it.

No, it stands for Light-Emitting Diode... LED Display would be perfectly fine. LCD Display is repetitive, however.

Title: I <3 morons
Post by: johnnysasaki on Fri, 10 December 2010, 19:33:54

Quote from: PAINKILLER;261002

Nah, that's how someone with RAS Syndrome (http://en.wikipedia.org/wiki/RAS_syndrome) would say it. You see, LED stands for Light Emitting Display, so it already has the word "display" in it.

Quote from: CodeChef;261043

No, it stands for Light-Emitting Diode... LED Display would be perfectly fine. LCD Display is repetitive, however.

:D I love Geekhack.

Title: I <3 morons
Post by: instantkamera on Fri, 10 December 2010, 19:37:46

Manyak is less than three morons?

Title: I <3 morons
Post by: msiegel on Fri, 10 December 2010, 19:41:09

:lol: less than three *light-emitting* morons

Title: I <3 morons
Post by: RickyJ on Fri, 10 December 2010, 23:06:09

Quote from: CodeChef;261043

No, it stands for Light-Emitting Diode... LED Display would be perfectly fine. LCD Display is repetitive, however.

Thanks for posting that.  When I read that my brain started twitching out and I had to go kill stuff for an hour to recover.

Title: I <3 morons
Post by: RoboKrikit on Fri, 10 December 2010, 23:10:03

(http://imgur.com/Z3Xz0l.jpg) (http://imgur.com/Z3Xz0.jpg)

Title: I <3 morons
Post by: msiegel on Fri, 10 December 2010, 23:12:54

when you sharpen that middle one, there's gonna be hell to pay

Title: I <3 morons
Post by: quadibloc on Sat, 11 December 2010, 01:07:19

I suspect the point of this is that a display built from light-emitting diodes is not going to need to be backlit. Since LCD and not LC is the common abbreviation, and one wishes to be clear that one is talking about a display, though, phrases like "LCD display" or "RAM memory" are hard to avoid if one wants to:

use an abbreviation instead of spelling things out in full,
use the most commonly recognized abbreviation,
still have the main noun explicit so that people who aren't familiar with the abbreviation can understand the sentence.

Accurate usage is good, but clear communication and conciseness sometimes take priority.

Title: I <3 morons
Post by: ch_123 on Sat, 11 December 2010, 03:27:42

In Dublin, there's a college called UCD (University College Dublin). There are also at least two UCDs in America, and amazingly, this was considered sufficiently confusing that the Irish UCD changed it's official name to "UCD Dublin".

Title: I <3 morons
Post by: woody on Sat, 11 December 2010, 03:49:51

Quote from: instantkamera;261056

Manyak is less than three morons?

I read that symbol for a long time like this, before someone explained it to me.

Also, U2711 is crappy.

EDIT: ... but at least cheap.

Title: I <3 morons
Post by: PAINKILLER on Sat, 11 December 2010, 05:47:07

Quote from: CodeChef;261043

No, it stands for Light-Emitting Diode... LED Display would be perfectly fine. LCD Display is repetitive, however.

What disturbs me is how many posts it took until someone saw what I did there.

Quote from: RickyJ;261146

Thanks for posting that.  When I read that my brain started twitching out and I had to go kill stuff for an hour to recover.

You just exposed yourself as a trollable guy. Be sure it won't stay unnoticed.

Title: I <3 morons
Post by: keyboardlover on Sat, 11 December 2010, 07:29:38

I love morans...

(http://www.apostropher.com/blog/img/morans.jpg)

Title: I <3 morons
Post by: Findecanor on Sat, 11 December 2010, 08:27:26

What kind of brain does mr Morans think that I should get? A sheep's brain or perhaps a cow's brain? I have never eaten brain, so I can not tell which one tastes better.

Title: I <3 morons
Post by: microsoft windows on Sat, 11 December 2010, 08:59:49

Quote from: keyboardlover;261253

I love morans...

Show Image

(http://www.apostropher.com/blog/img/morans.jpg)

And the sad thing is that guy's smarter than the ones leading our country.

Title: I <3 morons
Post by: RickyJ on Sat, 11 December 2010, 17:49:20

Quote from: quadibloc;261180

I suspect the point of this is that a display built from light-emitting diodes is not going to need to be backlit. Since LCD and not LC is the common abbreviation, and blah blah blah

iMav should change the name of this site to just "hack" because there seems to be a lack of geeks in attendance.

The actual display of an LED monitor/tv is absolutely no different from a regular LCD panel.  A traditional LCD has pretty much always used CCFL tubes for illumination, as the liquid crystal matrix does not produce light, it only filters wavelengths to give the appearance of colour.  An LED display uses the exact same LCD panel, but with a matrix of white LEDs to provide illumination.  White LEDs are a recent advancement, so the availability and cost of CCFLs versus white LEDs are the reasons for why things have been this way for years.  We'll save the TN/PVA/IPS talk for another lesson.

If anyone here remembers high school science (at a minimum), electrically exciting a tube of gases produces a spectrum with "spectral lines" that are gaps at certain wavelengths.  Combining gases helps to overlap these spectral lines, but they can still be dimmer than the rest of the spectrum.  This is why CCFL lighting has a limited colour gamut, and combined with the lowly 6-bit TN panel technology that has flooded the marketplace due to its cheap price, results in relatively poor colour production.  Since the CCFL tubes are mounted above and below the panel, the bending of light that has to happen in a CCFL lit LCD also reduces the colour gamut, look no further than the cover of Pink Floyd's iconic Dark Side of the Moon album to refresh your memory of high school physics.  The placement of the CCFL tubes also causes uneven light distribution, and light bleeding when not properly controlled.  CCFLs also age, reducing light output and also dropping portions of the spectrum.  CCFL lighting requires power circuitry to increase the voltage, which has been known to malfunction in panels that are not engineered properly (I've fixed more than my fair share).

White LEDs stand a much better chance of producing a proper spectrum, as long as they're made properly.  The LED matrix also provides a far superior light distribution pattern, does not require high voltage conversion, and is much more efficient.

To some, I am Rickipedia...

Title: I <3 morons
Post by: microsoft windows on Sat, 11 December 2010, 18:02:07

They seem to flicker a little bit. I saw some in the hardware store the other day.

They still sell the old C9 bulbs though. I use those in the tree in my front yard. You need the big bright bulbs if you want people to see your tree from a good distance.

Title: I <3 morons
Post by: RickyJ on Sat, 11 December 2010, 18:22:24

Quote from: ripster;261482

All I know is LED Christmas lights just don't look right.

LEDs aren't omnidirectional like incandescent lights, and their light spectrum is quite specific.  The flickering is from a lack of AC/DC power conversion, they wire a bunch of LEDs up in series to distribute the 120V, and let the nature of the diodes sort the rest of it out.  No transformers, no bridge rectifiers, no capacitors.  Since they have a forward voltage threshold before they conduct, they're not even shining at 50% duty, in fact it's much less.  They do literally flicker.

Title: I <3 morons
Post by: Konrad on Sat, 11 December 2010, 18:30:37

Actually my nitpick with the quote review involves comparing this 27" Apple Display with "many other higher end monitors".  Apple displays ain't all that, probably rebranded bin-downs from the LG plant.  I'd rather use a quality display, not an Apple one.
 
Not that I'm an Apple-hater, well not much, but this particular product is just branded mediocrity with an inflated price tag.

Title: I <3 morons
Post by: PAINKILLER on Sat, 11 December 2010, 18:58:16

Quote from: RickyJ;261495

The flickering is from a lack of AC/DC power conversion, they wire a bunch of LEDs up in series to distribute the 120V, and let the nature of the diodes sort the rest of it out.  No transformers, no bridge rectifiers, no capacitors.  Since they have a forward voltage threshold before they conduct, they're not even shining at 50% duty, in fact it's much less.  They do literally flicker.

So what, that's what you buy Christmas lights for - to blink and flicker. Else you could just replace your room lighting with a few different color light bulbs and still enjoy different colors, but it wouldn't bring the Christmas spirit that only those real Christmas lights can.

Title: I <3 morons
Post by: Fwiffo on Sat, 11 December 2010, 20:50:57

My brother has switched over to LED Christmas lights. He's going to save like $70 per month on electricity. Incandescent bulbs are comically inefficient.

Title: I <3 morons
Post by: RoboKrikit on Sat, 11 December 2010, 22:37:03

Quote from: RickyJ;261495

LEDs aren't omnidirectional like incandescent lights, and their light spectrum is quite specific.  The flickering is from a lack of AC/DC power conversion, they wire a bunch of LEDs up in series to distribute the 120V, and let the nature of the diodes sort the rest of it out.  No transformers, no bridge rectifiers, no capacitors.  Since they have a forward voltage threshold before they conduct, they're not even shining at 50% duty, in fact it's much less.  They do literally flicker.

Some of the light clusters on cars (e.g. brake lights) do this now, and it can be pretty distracting.

Title: I <3 morons
Post by: microsoft windows on Sun, 12 December 2010, 06:26:39

Quote from: Fwiffo;261543

My brother has switched over to LED Christmas lights. He's going to save like $70 per month on electricity. Incandescent bulbs are comically inefficient.

I still use the big C9 bulbs on my Christmas tree outside. They're nice and bright.

Title: I <3 morons
Post by: Manyak on Sun, 12 December 2010, 10:30:20

Quote from: RickyJ;261480

This is why CCFL lighting has a limited colour gamut, and combined with the lowly 6-bit TN panel technology that has flooded the marketplace due to its cheap price, results in relatively poor colour production.

Believe it or not it's the other way around. For example, let's compare the Apple Cinema Display to the Dell U2711h. They both use the same LCD panel, but the Apple uses LEDs and the Dell uses CCFLs. However, the Dell has a wider gamut:

(http://images.anandtech.com/graphs/apple27inchcinemadisplay_092610174635/24902.png)

The Dell also has better accuracy, even after both have been calibrated:

(http://images.anandtech.com/graphs/apple27inchcinemadisplay_092610174635/24901.png)

For LEDs to equal or surpass CCFL, they have to be RGBLEDs, so that the backlight color can be adjusted per pixel as needed. The problem is that white LEDs just aren't really white.

Just go look at all the high end panels from Eizo, LaCie, NEC, and so on. They're all either CCFL or RGBLED for that reason.

Title: I <3 morons
Post by: microsoft windows on Sun, 12 December 2010, 10:39:32

And my trusty old Trinitrons get better color and accuracy than any of those LCD's.

Title: I <3 morons
Post by: Manyak on Sun, 12 December 2010, 12:40:45

Quote from: microsoft windows;261682

And my trusty old Trinitrons get better color and accuracy than any of those LCD's.

While it is technically possible, all computer CRTs were designed for sRGB only. The higher end Sony and NEC screens did go past sRGB, mostly in the blues, but not by much. Their accuracy is much higher though, assuming you're calibrating the hardware regularly.

TVs were able to display the full NTSC color space, but as a side effect of the increased gamut the phosphors had longer decay times. This made high refresh rates impossible. And the staggered rows of phosphors along with interlaced scanning made the image inaccurate for all resolutions greater than 640x400 (give or take).

Title: I <3 morons
Post by: Brian8bit on Sun, 12 December 2010, 12:47:26

If MW was any further back in time he'd be Fred Dibnah.

Title: I <3 morons
Post by: RickyJ on Sun, 12 December 2010, 21:25:43

Quote from: RoboKrikit;261583

Some of the light clusters on cars (e.g. brake lights) do this now, and it can be pretty distracting.

That's from the PWM circuitry, they generally run at a pretty low frequency.  Video cameras can catch it, that's why LED tail lights appear to flash randomly when you're watching a show like Top Gear.  LED lighting on cars has to be pretty powerful, but running 100% duty would draw too much current and burn them out, so they run them via PWM to keep the lifespan and heat under control while still maintaining brightness.

Title: I <3 morons
Post by: CodeChef on Sun, 12 December 2010, 21:29:32

Yes.

Title: I <3 morons
Post by: Konrad on Sun, 12 December 2010, 21:45:40

I'd always wondered how those superbrights didn't overheat.  PWM, duh ... yeah.  Frequency is probably divided off 20MHz, or more likely 4MHz ulogic.  Although visual artifacts on 30fps video suggests a frequency < 30Hz.  Maybe it's based on surges of electrical alternator rpm.

Title: I <3 morons
Post by: RickyJ on Sun, 12 December 2010, 23:21:47

Quote from: Konrad;261998

I'd always wondered how those superbrights didn't overheat.  PWM, duh ... yeah.  Frequency is probably divided off 20MHz, or more likely 4MHz ulogic.  Although visual artifacts on 30fps video suggests a frequency < 30Hz.  Maybe it's based on surges of electrical alternator rpm.

I haven't looked at the datasheets of any high powered LEDs, but I suspect their activation time is not nearly as quick as normal low power LEDs.  I also suspect that they keep frequencies low to keep their switching transistors happy, high current stuff doesn't usually switch quickly.  Have to keep designs simple in automotive safety equipment too, huge safety factors.

I should really take a peek at the drivers for my stock LED tail lights in my BMW.  Would be quite interesting, I like studying design methods.

Title: I <3 morons
Post by: Konrad on Sun, 12 December 2010, 23:45:53

I've actually done something similar with IREDs, "pulsing" them far beyond their rated Isurge(FM) ratings (it was a bright IR "spotlight" to play with my cheap "nightvision" camera, ie: digital cam with internal IR filter plastics removed).  Also functions as a superb "remote control jammer" because it drowns out other signals *and* has enough transmission range to affect the neighbour's TV through two closed windows, heeheehee.
 
Little LEDs can burn quite bright but just don't have enough junction surface area to radiate a lot of heat; they can be "pulsed" momentarily (PWM "oscillator" style) easily 50X above their normal limits, provided they have enough cool-down time. I'm thinkin' that larger LEDs are more robust but can basically operate on the same principle. I'd have to read through boring datasheets to find out.

Title: I <3 morons
Post by: Manyak on Mon, 13 December 2010, 00:31:08

Quote from: ripster;262002

Chart doesn't have the new Dell $1500 U3011 (http://accessories.us.dell.com/sna/productdetail.aspx?c=us&l=en&s=dhs&cs=19&sku=224-9949&~ck=baynoteSearch&baynote_bnrank=6&baynote_irrank=0).  Should I buy this one?

It's the same panel as the HP, but with CCFLs instead of RGBLEDs. It's a bit more accurate, but not as wide gamut (99% Adobe98 spec'd, I don't remember what it tests at). It gives you offset, gain, and hue control - with your calibrator you should be able to get it 100% perfect.

If you're interested I've got a 6 month old 3008WFP for sale by the way. Not the same, but still gorgeous, and about half the price.

Title: I <3 morons
Post by: woody on Mon, 13 December 2010, 07:47:31

Quote from: Konrad;261998

I'd always wondered how those superbrights didn't overheat.  PWM, duh ... yeah.

You're interested in the integral current. Also, more current -> more migration -> less life.

Quote

Frequency is probably divided off 20MHz, or more likely 4MHz ulogic.  Although visual artifacts on 30fps video suggests a frequency < 30Hz.  Maybe it's based on surges of electrical alternator rpm.

Beating frequency tells nothing about PWM carrier, which is usually in the kHz range.

Title: I <3 morons
Post by: woody on Mon, 13 December 2010, 17:09:18

Wait for PA301W.