The bad old days

Since their introduction, LCDs have suffered from a significant problem: the contrast varies a lot with even a small change in the tilt of the display. In fact, the contrast varies even from the top to the bottom of the display, because the angle of view varies from top to bottom. CRT displays didn’t have this problem. If you are a photographer or artist, you certainly know what I mean.

A new crop of LCDs

But there is good news. Some of the more recent LCD displays are free of this drawback. You may not realize just what a big deal this is until you see one of the new displays for yourself.

We need a new term: “uniform-contrast”

I have seen very little published on this important new development, either in product reviews or in product literature. As far as I can tell, there is not even a concise term for the feature. I propose the term “uniform-contrast”. It’s pretty much a yes or no thing.

A test pattern to show off the new feature

I made a full-screen test pattern that reveals contrast unevenness related to viewing angle. In the photo below, notice how the diamonds are darker at the top and lighter at the bottom. The photo shows the test pattern displayed on my late-2007 MacBook Pro (which is no worse than every other laptop and most other displays today). On a uniform-contrast display, the pattern looks the same top to bottom.

Try the full-screen test pattern on your display. It's quite a different experience from looking at the images below. At the end of this page, I explain why.

Another cool new LCD display feature: glass!

Apple's use of smooth glass instead of matte-finish plastic on their new LCD displays fixes another long-standing subtle problem with LCD displays: the grainy-film look. Because of the way LCD displays are made, the matte finish brings out a random multicolor pattern, which is especially visible in solid color areas. The worst part is that each eye sees a different pattern. I find this disparity between the two eyes quite uncomfortable.

Good displays on current products

There are very few of the new, good LCDs on the market, and many are overpriced. Here are some of them (not updated for new iMacs and other newer displays):

	Apple MC007LL/A 27-inch LED Cinema Display (glass) $999.00
	Apple MB382LL/A 27-inch LED Cinema Display (glass) (discontinued) $899.00
	Apple iMac MB325LL/A 24-inch Desktop PC (2.8 GHz Intel Core 2 Duo, 2 GB RAM, 320 GB Hard Drive, DVD/CD SuperDrive) (glass) $1,449.98
	Apple Cinema 20-inch Flat-Panel Display (matte finish plastic, discontinued) $594.00
	Apple Cinema 23-inch HD Flat-Panel Display (matte finish plastic, discontinued) $944.00
	Apple Cinema 30-inch HD Flat-Panel Display (matte finish plastic, discontinued) $1,770.16
	HP LP2475W 24-inch LCD Monitor 1920X1200 $625.89
	NEC Computers LCD2490WUXI-BK 24-inch Widescreeen LCD Monitor $1,099.99
	NEC Computers LCD2690WUXI-BK 26-inch Widescreen LCD Monitor $1,199.99
	NEC LCD3090WQXi-BK 30-inch Widescreen High Resolution LCD Monitor $2,101.99
	LaCie 526 Widescreen 25.5-inch LCD Monitor (part no. 130764) $1,642.99
	Planar PX2611W 26-inch LCD monitor $793.99
	Wacom Techno Cintiq 21UX 21-inch Interactive Pen Display PC Tablet With Pen and Software $1,999.00
	Wacom Cintiq 12WX 12-inch Pen Display $940.20

Also (courtesy of TFT Central):

Doublesight DS-305W	30"
Hazro HZ30W-Q5	30"
Hazro HZ30WB-Q5	30"
Hazro HZ24W	24"
Hazro HZ24Wi	24"
Hazro HZ26W	26"
Hazro HZ26Wi	26"
HP DreamColor LP2480zx	24"
NEC MDview 262	26"
NEC SpectraView 3090	30"
NEC SpectraView 2690	26"
Philips 240PW9EB/00	24"

Complete current list of H-IPS displays on the TFT Central web site.

Displays on other products

I went to Fry’s, Circuit City, Best Buy, and Costco.

Only one non-Apple display at all these stores was uniform-contrast: the 21" Wacom interactive display, at Fry’s. Everything else, standalone displays, all-in-one computers, laptops, netbooks, had the bad old technology.

Most LCD HDTVs in the thousands of dollars seem to be uniform-contrast in the vertical direction, but the horizontal direction is not so great. For example, my test pattern revealed that the Toshiba 40RV525U is perfectly uniform-contrast vertically, but the contrast is lower (or is it higher?) at both the left and the right sides compared to the center. I look forward to trying the test pattern on Panasonic HDTVs, particularly the TC-37LZ85.

Here is a list of the products I saw at Fry’s and can verify as not having uniform-contrast displays:

Standalone LCD monitors - bad old varying-contrast

Acer 919SW Acer P191WD Acer P221Wd Acer X203Wbd Acer X263WBI AMW A912WDB AOC 19MVWk AOC 416VA AOC 2216SW eMachines TFT19W80PS Emprex LM-2202 Envision G19LWK Envision G22LWK Envision G917W1 Envision H170L

Gateway FHD2201 Gateway FHD2401 Gateway HS2200 Gateway LP1925 HP W2207H HP W2408H HP W2558HC Hyundai W240D Hyundai X93W LG L227WTG-PFPF LG W1934-5N LG W2252QTQ-TF LG W2452T-TF LG W2600H-PF LG W22345-BN

NEC 194WSM-BK NEC 224WXM-BK Optiquest Q19WB Optiquest Q241WB Optiquest Q2201WB Samsung 920NW Samsung 932BW+ Samsung 943BWX Samsung 953BW Samsung 2243BWX Samsung 2253BW Samsung T220 Samsung T220HD Samsung T240 Samsung T240HD

Samsung T260 Samsung T260HD Tyris T902WDT Viewsonic VA2026w Viewsonic VA2626WB Viewsonic VX1932WM Viewsonic VX1962WM Viewsonic VX2262 Viewsonic VX2263 Viewsonic VX2835WM Vision V193WDB Vision V194WD Vision V221 WD

All-in-one-computers - bad old varying-contrast LCD displays

Apple iMac 20-inch (glass, tho) HP IQ 504 HP IQ 804 Sony VAIO VGC-JS110J

Laptops - bad old varying-contrast

Acer A5315-2698 Acer A6390-6154 Apple MacBook Pro (glass, tho) Apple MacBook 13.3-Inch (glass, tho) Compaq CQ50-120US Compaq CQ50-130US Compaq CQ50-210US Fujitsu A1110-72 Fujitsu A1110 Fujitsu A6220-32CL Fujitsu N7010-2102

HP DV4-1140GO HP DV4-1144US HP DV5-1116US HP DV5-1150US HP DV9922US HP G50-103NR HP G50-106NR HP G60-120 HP X16-1040US HP X18-1020US Lenovo U110-7230UK

Sony AR8305 Sony AW110J/H Sony CS115J/Q Sony SS110E/P Sony VGN-2520N/B Sony VGN-FW230J/B Sony VGN-FW248J/B Sony VGN-NS115N/S Sony VGN-NS140E/S Toshiba G55-O804 Toshiba L305-S5896

Toshiba PSLC8U-023010 Toshiba PSLD8U-01HODY Toshiba S5891 Toshiba S5911 Toshiba S5912 Toshiba S5913 Toshiba S6883 Toshiba S6885 Toshiba S7829 Toshiba T3200 Toshiba X305Q705

The technology

According to Wikipedia, the LCD technology you want is H-IPS (horizontal in-plane switching). NEC has a pretty good description of in-plane switching, which they call XtraView.

Correcting for varying-contrast LCD displays

Suggestion for Apple: the Display Calibrator’s expert mode calibration pattern should cover the screen more like my test pattern does, and it should offer sliders to compensate for top-to-bottom and left-to-right variation. The result would be an effectively uniform-contrast display for a given viewing angle and distance.

Extra credit: How the test pattern works

My test pattern uses a trick I first noticed in Apple’s Display Calibrator application (accessible via System Preferences / Displays / Color):

Each diamond shape in my test pattern (like the Apple logo above) is made of greyscale pixels, whereas each rectangle is made of alternating lines of two different grey values that average out to the same grey value. IBM's patent number 5,298,993 describes "adjustment images with a symbol that appears light on dark when misadjusted in one direction; dark on light when misadjusted the other way; and disappears at the point when the display is adjusted correctly" so it would appear that IBMers first invented this technique.

http://Yost.com/computers/uniform-contrast/index.html - this page
2008-12-07 Created
2008-12-25 Modified
2010-04-15 Added link to NEC tutorial on IPS
2010-11-19 Added Apple 27" display