Hi Dave, I asked a friend who I know is pedantic about these things:
There are a bunch of things that could be causing problems. Using DVI-D (digital) connections for both displays will probably help, at least you will be using the same image processing circuitry in both displays and same behaviour from the display driver then. Go through all of the display menus on both panels and make sure they match (particularly colour/white point temperature). Having the same settings on both doesn't guarantee that they'll match (see below), but you should start there and then, from that point, try tweaking one of them towards the other. Often the displays don't offer much control via the on-screen displays when using DVI-D connections, so you may have to use options in the display drivers instead or in combination. The backlight in the displays becomes dimmer with age (and takes longer to reach peak brightness). This is affected by the number of hours the backlight has been running rather than the actual age of the display. A dimmer backlight affects both the brightness (obviously) and will also affect colour to some degree. If you need accurate colour rendition, the you need to use a colourimeter to calibrate the monitors. If the displays are quite different, this will not get them looking the same, because the colourimeter can't deal with differents in brightness or dynamic range, but at least the colours will be accurate. If there's already a colourimeter in the company, this might be the best place to start first... otherwise the cost of a colourimeter starts at around $250. Manufacturers make changes to the monitor builds over time, so it's possible that the same model monitor may be built with a completely different image processors, firmware, LCD panel, and backlight. If the serial numbers are very close, this is unlikely, and for higher end displays the parts used in the build tends to be much more consistent. Having said that, I have two 24" Dell displays (hardly print-press quality, but they are higher end displays) that were bought about 2 months apart that have different panels and quite different brightness and colour rendition. Cheers, -mjg > > >>> Dave Reynolds <dave.reynolds at tait.co.nz> 5/09/2008 1:51 p.m. >>> > Hi > > Not exactly Frame related, but I'm after some advice about LCD > monitors. After being the only tech writer in our team with a single > monitor, I finally got given another monitor a couple of weeks ago. > Hurray!! It's been a long wait. So now I have matching Viewsonic VA912 > 19" monitors. The second one is not new, but reassigned to me from > someone else. Judging from the numbers, it is about the same age as my > first monitor. > > Apparently my PC has an on-board video card, so they connected the > second monitor via an adaptor card (budget constraints!). This meant I > had the first monitor on an analog feed, and the second monitor on a > digital feed. > > The display on the second monitor is quite different from the first > monitor in terms of colour, brightness and contrast. I have tried to > adjust the second monitor to match the display of the first monitor, but > I've been unsuccessful. I've tried the adjustments on the monitor and > in the driver, but the display on the second monitor is still inferior > to that on the first monitor. After complaining to our IST people, they > fitted a new video card that they happened to have in stock (still > budget constraints), but I notice that the first monitor is still on > analog, and the second is still on digital, and I still can't get the > displays to match. > > For many applications this is only a nuisance. However, for editing > photographs it is a major problem. I take quite a few photos for my > manuals and it is important that the edited versions of the photos I > take are consistent for colour, brightness and contrast. This means > that I cannot currently use the second monitor for editing photos, as > the same photo looks so different on each monitor. > > Is there a way to get the second monitor to match the first one, or am I > fighting a losing battle trying to get the digital input display to > match the analog input display? > > Any help appreciated. > > Thanks > > Dave -- Matthew Gregan |/ /| kinetik at flim.org NOTICE: This message contains privileged and confidential information intended only for the use of the addressee named above. If you are not the intended recipient of this message you are hereby notified that you must not disseminate, copy or take any action in reliance on it. If you have received this message in error please notify Allied Telesis Labs Ltd immediately. Any views expressed in this message are those of the individual sender, except where the sender has the authority to issue and specifically states them to be the views of Allied Telesis Labs.