Monitor "Refresh Rate" reported by Windows
I'm trying to solve an apparent eye-strain computer use relationship. Please show me where I'm wrong about this!
I think, when Windows XP reports (in Control panel/Graphics/Settings/Adv) that 60 Hz is the "optimal refresh rate" (also maximum) for a LG 22" LCD monitor configured for 1920 X 1080 pixels and VGA interface, XP reports what's in the monitor .inf file, and that the particular monitor can't run any faster, by design. The user's guide says Horizontal Sync Frequency is automatic in the 30 - 83 HZ range, and Vertical Freq, is 56 - 75 Hz, also automatically controlled.
If I'm wrong (I want to be), Windows factors in info about the video card, Northbridge, and maybe the CPU as well.
I want at least 70 Hz, but don't think I can achieve it with this monitor. Do I need to ditch the monitor, or is there something else that will bump up the refresh rate without buying a new LCD?
Windows only takes the information the monitor sends to the computer and the driver information for that video card.
If you want a faster refreash rate you need to lower the resolution to something like 1280 X 1024.
Thanks, Sue. So, I'll find another use for this monitor, then start shopping. 73
Originally Posted by AF6LJ
What problem are you trying to solve?
I'm no expert but I don't think refresh rate is particularly important for an LCD monitor. I don't think you get the flicker that you get with a CRT screen if the refresh rate is too slow.
I guess refresh rate for an LCD just means how quickly the image can change. That might matter while watching moving videos but it probably doesn't make much difference in most computer situations.
That would be a better setting for that monitor.
Originally Posted by AF6LJ
The eye strain is more likely to happen at the higher screen resolution, and refresh rate on a LCD has little to do with Eye strain.
"Theory only works perfect in a vacuum." KA9JLM Don
Thanks for all your inputs! I came to this forum knowing I'd get straight talk with best intentions.
Originally Posted by KT1F
There is a considerable amount of evidence from web searches, that whether you call it "refresh" or flicker speed, or write-rewrite speed, with a LCD monitor faster is better for many eyes. As with CRT displays and TVs, the slower the refresh rate is, the more eyes attempt to track every single minute change in an image. Not everyone's eye muscles are equal. They're some of the tiniest muscles in the body, yet we often work them excessively.
I forgot to say, I plan to replace the graphics card with a much faster card before I scrap the 22" LG. I want 1920 X 1080. I'm convinced it can be done, one way or another, without excessive eye strain.
In fact, the refresh rate has virtually no effect on LCD monitors.
Originally Posted by KT1F
The refresh rate actually sets the speed at which the computer redraws the image on the display. In the case of CRT displays, the phosphor on the screen starts to dim very quickly after it's hit with an electron, so higher refresh rates prevent flicker. Also, refresh rates that are NOT 60Hz help prevent interaction with fluorescent lights.
However, LCD monitors don't work this way. The pixels stay in their current state until they're changed, and so there's no flicker - at any refresh rate. Because of this, LCD monitors don't accept refresh rates of anything other than 60Hz any more.
If you're having eyestrain problems, the issue could be resolution, brightness, or a need for glasses.
If the screen appears blurry - even when you're using the native resolution of the display, you could also be using a bad VGA cable. LCD displays do a very good job of showing the defects in cheap video cables, and they really highlight reflections when you use extension cables. Those reflections create a ghost effect on the screen, causing text to "smear" to the right.
The best quality you're going to get is to use the display's native resolution and use a digital video cable: either HDMI or DVI. Once you've done that, then address issues with lighting and see if that helps.
That's the ticket Gary, faster graphics card...
Originally Posted by NM7G
They are cheap and if you have seventy-five dollars or so to shell out a nice card that will do the job can be had.
1. I have new glasses, with PC use factored in.
Originally Posted by KI6ABZ
2. I've placed a black curtain behind my chair to block extraneous light from striking the screen
I agree that 60Hz seems to be the standard now for new monitors, but that doesn't change human physiology. I believe the many people who say they gained relief with higher refresh, even if it's a placebo effect. The brain is the vision organ anyway. Eyes are input sensors. The brain controls eye muscles, so let's fool it if it works. The term refresh rate may seem archaic, but LCDs have a Response Time, the time it takes to change color of a pixel, then change it back to its original color. If the image I'm viewing has 2M pixels, and 500k of them change color abruptly, isn't that affecting the brain similarly to repainting an electron beam across phosphors on a CRT? It's change.
It seems likely that 2.07M pixels are a big part of the problem. On my other PC, I do video editing, EZNEC modeling, and a little CAD on a 17" CRT. It doesn't tire my eyes nearly as badly, however, it runs 1024 X 768, a third as many pixels.
Great inputs folks! I'll see this through to a conclusion and let you know how it turns out.
Last edited by NM7G; 05-09-2012 at 07:10 PM.