Those of you who have had the chance to compare the old LCDs with the latest models can truly appreciate the progress of this technology over the last few years. It really seems like flat panel displays are finally ready for prime time with their colour reproduction and response time improving on pretty much a monthly basis.
There is more to Flat panels than first meets the eye. For one the specs themselves seem to reveal very little about picture quality. LCD monitors fall into two categories. Those that look good and those that look good on paper. Take all numbers quoted by manufacturers with a grain of salt.
There are a couple of major parameters often quoted by LCD manufacturers:
- Brightness. This is the amount of light that the LCD emits from a pixel displaying the white colour. Usually quoted in Candelas/m2 or nits (same thing). Expect to see values between 220 and 350 (with Solarism being extreme at 800).
- Contrast ratio. This parameter describes the ratio of brightness level between a pixel that is fully off (displaying pure black) to one that displays white. In practice this figure seems to matter less than one would have thought. Anyway expect it to be between 300:1 to 500:1.
- Viewing angle. This describes the maximum angle from which the monitor can be viewed with no more than 20% brightness loss. Expect to have at least 160 degrees horizontal and vertical.
- Response Time. It describes the time it takes for the pixel to switch from fully on to fully off and vice versa. Leading edge displays deliver 25ms with 15ms for rise time and 10ms for the falling time adding up to 25ms total. Some manufacturers are deceitful and quote only the rise time as their response time.
- Input type(s). Basically there are two types of inputs a flat panel can be fed the signal from a computer. The RGB input (or D-sub) which is the same as your standard CRT. This solution offers mediocre picture quality due to signal degradation through double conversion (D-A, A-D). A much better solution is to use the DVI input with a flat panel. The difference in text quality can be quite amazing at high resolutions. Don't even consider a flat panel that doesn't have a DVI input.
Surprisingly, picture quality in LCD monitors seems to vary quite a bit from one LCD manufacturer to another.
The modern panels use three types of LCD panels depending on the alliances and deals they made with the glass panel manufacturer. Virtually all modern LCD panels incorporate some form of technology to widen the viewing angle since LCDs naturally have pretty poor viewing angles.
The first (and oldest) technology is known as TN+film which widens the viewing angle by using optical coating that helps increase the viewing angle of the panel. It is the simplest and cheapest approach that yields unimpressive results with viewing angles of 140 degrees or worse.
In plane switching (or IPS) is a very common technique for widening the viewing angle of a flat panel. The technology increases the viewing angle by polarising LCD molecules to be aligned parallel to the substrate. IPS displays tend to have extremely high viewing angles (usually around 170 degrees) and average response times.
Multidomain Vertical Alignment (or MVA) displays are another type of flat panels designed for improved viewing angles. MVA displays attain viewing angles of around 160 degrees and fast response times. But MVA sounds better on paper than in reality. Read on to learn about problems I've seen in MVA displays.
I am in the market for a flat panel display as we speak and already "purchased" a number of them to subsequently return them back to the manufacturers for a refund. What follows is my experience with some of the common flat panel displays that I had a chance to look at. All displays reviewed below work with the native resolution of 1280x1024:
The 1850E is a 18.1" flat panel with the native resolution of 1280x1024. It is most likely an IPS panel although NEC won't tell you that. The panel has nice colour reproduction with deep blacks and bright whites but there is a big drawback to this screen. It's a D-SUB only monitor! If text quality is not your primary concern in a monitor it may well be adequate but its response times are not good either making it a poor choice for games and movie watching. It does do a good job of rendering colour, however. I returned this screen to FutureShop under their 30 day no quibble money back guarantee. Overall: 5/10
The Samsung is a truly stylish monitor. Beautiful on the outside it has little to offer in terms of picture quality however. Despite being a screen with digital input (it has one DVI and one RGB socket) and the theoretically superior MVA panel, the text quality is only average. This is caused by very poor colour reproduction on the 181T. Black levels are particularly problematic with the monitor displaying black colour as a somewhat darker shade of grey. Its quoted 500:1 contrast ratio (in theory excellent) makes one really sceptical about the numbers Samsung quotes for their products. Whites are very bright on the 181T (almost too bright) and there is a good selection of adjustment options in the analogue mode. Unfortunately my 181T blew up within two weeks (most likely power supply failure) and was sent back to the shop for a refund. I can't say I miss it all that much to be honest with you. I'd give it 6 out of 10 as it's marginally better than the NEC.
Samsung 171 B
I had a chance to play with this monitor at my local Future Shop store. All other units were hooked up to my own computer except for this one. However, I had a chance to play with this screen for quite a while and had it hooked up to a PC powered by the ATI Radeon 7500 which is a pretty decent graphics adapter. Thus I decided to include a review of this monitor along with the ones I actually bought.
It is probably an MVA screen as it seems to share a lot of the drawbacks with the 181T. It is not very exciting really as it is an analogue only screen with a mediocre set of parameters and poor colour reproduction to boot. I have no idea who is in the market for such a screen. Poor text display, no DVI and the $1100CAN price tag makes it look like one of the first screens to rule out when deciding on an LCD purchase. Rating: 3/10
I have the Dell 1702FP at work on my desk as part of the OptiPlex system.
This screen has only 17" across the diagonal but delivers very crisp and sharp picture with excellent text output under the DVI mode. Analog is slightly worse but not by much. 1702FP is the best LCD I have seen for reproducing the black colour. It's deep and convincing. A black bitmap image makes the screen look as if it were powered off! Very impressive indeed. Unfortunately white levels are a bit off on this monitor with a noticeable hint of green. The IPS technology used in this monitor is the double edge sword that makes the black level so deep and the white level not too great. Overall though the picture is very nice to look at with saturated colours and amazing text quality. It can be had for less than $1000CAN which makes it a pretty nice bargain. Its response time in games is excellent even though Dell don't quote the actual number it must be impressive nonetheless. It is ideal for almost everything except for family viewings of DVDs as 17" is not all that much for movie watching. Don't think however, that the inherently small type on this screen is difficult to read. It's an excellent choice for prolonged coding sessions and a monitor I've yet to see beaten on the overall picture quality. Rating: 9/10.
Well there you have it. You probably want to know which one I settled for. The answer is: don't know yet. I'm about to receive the "big brother" of the 1702FP, the Dell 2000FP. If it lives up to the standard of its little brother I'll be a happy customer. However, with monitors more than anything else in PC hardware, one man's trash is another man's treasure, so shop around till you find something you like and make sure the purveyor has a flexible return policy so you don't get stuck with something you paid big bucks for but don't really like all that much. And the more of them you see the more you'll realise what kind of tradeoffs there are and which shortcomings you are most prepared to accept.
One thing is for sure. Flat panel displays are here to stay and now is as good a time as ever to consider one if you can swallow the price tag.