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Is CRT Burn-In Still a Problem?
coloth asks: "We've all been told for many years that monitor burn-in is a thing of the past, that CRTs use a different kind of phosphor now, and that screensavers are more toys than practical safeguards. After a few minutes with Google, nearly every PC advice site I found said as much. Well, I just realized tonight that I've got burn-in from the Seti@Home screensaver on my Dell P991. I took a picture with my digital camera. (disregard the bar of interference) I added the arrows with PhotoShop and enhanced the image a bit, but the burn in is clear. Here is the image of the "screensaver" to compare the pattern. Is my monitor sub-par? Is the conventional wisdom about burn-in untrue? Are most people doing anything specific to avoid burn-in?"
Every computer at my (ex)university had that same problem. Seti@Home (And, actually, all of the distributed-computing project 'screen savers') make extreamly POOR screen savers. If you're going to set it up like that, you should enable the "turn monitor off" option if your monitor is capable. (Saves electricity, too)
=Smidge=
Also keep in mind that your monitor sucks down a lot of power anyway - you'd save power just powering it down.
This sig no verb.
Apparently plasma screens are particularly suceptible to screen burn, and the so-called 'DOG' (Don't know what it stands for, it means the logo of the station/programme you're watching) often gets burnt in if you watch one channel frequently. The displays in the BBC TV newsrooms used to show this effect, but they've either been replaced or recalibrated.
I just wish they'd stop cluttering *my* screenspace.
-Yarn - Rio Karma: Excellent
Yes, Virginia, phosphors do wear out over time. The problem used to be much, much worse.
... turn the darn monitor off for a power consumption of maybe 2 watts (off doesn't quite mean off). A friend and I went to ridiculous lengths during the California energy crisis to persuade his tech company IT dept. to tell everyone to turn off their 3,000 machines when not in use, or at least overnight, or AT LEAST over the weekends and holidays.
... they could upgrade the O/S ... but what they have works. There are cheap utilities that persuade NT to play along, but that would require getting the IT people to install it, and if they were unwilling to listen about turning monitors off, well.... you get it.
:)
I hate screensavers that run more than ten minutes -- they rarely seem clever any more, and more importantly they seduce a lot of people into thinking they are somehow saving energy. In fact, if the tube is fired up the box is consuming nearly full power and releasing nearly full heat.
MUCH better is any kind of sleep mode, which might reduce a 75-watt load to 5 watts. Or
They told workers to leave them on because of the old tale that electronics last longer that way. More research, I eventually reached a very friendly engineer with the Sony monitors operations. In short, the leave-'em-on philosophy made some sense before all solid-state surface-mount design prevailed because of thermal shock and "creep," which made IC's rise in their sockets. Now everything is soldered and the components are many times more reliable. In terms of monitor wear, it's probably a toss-up. No one would seriously leave their TV on 24 hours a day to save money, right? And even if wear were accelerated somehow with the machines on 1/3 as long, the amount of energy consumed would have bought a ton of hardware.
We calculated the excess electrical in the hundreds of thousands of dollars, and that's before factoring in the added load of the air conditioning to remove the waste heat (most of the energy used goes to waste heat). (A rough guess: the best estimate I could find suggested it takes 1 watt of A/C consumption to remove 3-4 watts of heat.) There was also a citizenship issue to energy conservation at the time, as there were rolling blackouts to ration energy the closer the system came to overload. (You all remember the stories.)
Um, anyway, I hope I made a point. Er, my point. One thing Apple did right was to support Energy Star early on. "By design," MS Windows NT 4.0, which his company uses, does not support power mgmt even though the newer monitors typically do. Yes
I think they did start telling employees to turn the monitors off just recently, maybe 18 months after our email campaign and a half-million in electricity. Could the computers be next? They're just dumb workstations and don't do anything in the off hours.
Last nail in the coffin: To give you a sense of his IT department, they sent a tech down once who could not be made to understand, by several engineers, the difference between a SCSI and a parallel port ("Well, it should fit."). No shit.
AFAIK, the screensavers in xscreensaver don't burn anything in, because they keep things moving enough.
/etc/X11/xdm/Xsetup_0 I've added the lines:
But if we're going to gripe about pollution, Big Oil, and the like, we should be using DPMS. It's not tightly linked to APM or ACPI, or other power-saving features. It's right there in X.
For my example, in
"/usr/X11R6/bin/xset s noblank s 200 60"
"/usr/X11R6/bin/xset dpms 300 1800 2400"
The first line puts the good old X screensaver into action, and the second line handles DPMS. The three DPMS numbers are the times when progressive power savings kick in. By having these lines in the xdm configuration, you get the screensaving features even at the xdm or gdm login. (Gdm symlinks to Xsetup_0, I don't know about kdm.) By the time the third powersaving mode kicks in, your tube uses about as much current as a night light.
The flipside of burn-in is cathode poisoning. That happens, or happened, when the tube is blanked, but still active. I don't know if it's still a problem with modern tubes. But it takes so little to avoid, why not. That's why I kick the X screensaver in, and turn off blanking.
The living have better things to do than to continue hating the dead.
You mean "bug", not "dog".
Note that the shape of the burn in matches that big, bright blue diving bar thing in the SETI@HOME screensaver screen capture.
Karma: Excellent (fuck, even in the future moderation doesn't work!)
SETI@home has a built in option to blank the screen (without turning off the monitor or doing any fancy Energy Star stuff) after a certain amount of time. They even recommend this because the video code takes some time away from the CPU. There's no excuse for not using this.
Omnes arx vestrum sunt adiuncta nobis.
No, "dog" is also correct - stands for "Digitally Originated Graphics". There are several campaigns running to try to persuade broadcasters to remove them for reasons such as burned TV screens and aesthetic damage to programmes and films infected with them. See here and here for more info.