Dell have always had a very strong range of panels available, from the strictly low end mass market TN panels for the budget aware audience to the high end 30 inch panels for the discerning designer and enthusiast.
A few weeks ago we looked at their bargain SP2309W which we were extremely impressed with – for the outlay (£160-180) it really is hard to beat, even when factoring in a few necessary compromises to hit the price point. We asked Dell to send us what they thought was their finest screen in the sub £500 zone and they kindly obliged. Today we are looking at a more expensive model – the £450 UltraSharp U2410 which has moved away from the PVA panel design of the other higher end models in this range to adopt IPS standards.
‘So whats the deal with IPS?'Well the reasoning behind this is that for colour reproduction IPS is actually a superior technology. This H-IPS screen has some rather incredible specifications, with a 8,000:1 claimed dynamic contrast ratio as well as 96% Adobe RGB (110% sRGB) colour gamut.
In theory a larger colour gamut is always going to be an advantage as this will enable the screen to display colours that a monitor with a smaller gamut will never be capable of achieving. It is important that a colour gamut is not confused with the amount of colours a monitor can display, which is generally 16.2 or 16.7 million. A colour palette works in conjunction with the gamut range.
A colour gamut is the range of colours the monitor is able to display while the amount of colour is how many gradations this overall range is split into in order for the panel to display medium hues or halftones. A color gamut is in fact a hardware property of a monitor that is not dependent on the system involved.
Obviously the number of colours determine the difference between two adjacent colours and the more colours a monitor can display the smaller this difference will be. The entire range of colour the monitor can reproduce is split into 16.7 million dots with each specific colour being as accurate as just a single dot on the panel.
When this range – the colour gamut gets larger or expands and the number of dots is identical then the difference between the adjacent dots gets bigger. Therefore, although an extended gamut monitor can display more colours in a physical manner it does so with slightly reduced accuracy. This lower colour precision will be observed when studying the smoothness of colour gradients – they will appear banded with each band corresponding to a single colour dot.
You will even see this problem with 24-bit colour representation that is the standard today. Graphics cards work with 32 bit colour but there are only 24 bits that totally define colour, the additional 8 bits are there for other purposes. Actually these extra 8 bits have been introduced only because graphics cards handle 4 byte numbers easier, rather than 3 byte. If we stretched a gradient of colour from red to black across a full panel you would see it to be striped rather than smooth. A bad monitor would also add wider and further abnormalities to the final image.
So this “banding” of the colour gradient will be even more apparent on an extended gamut screen if we use an identical 24 bit colour format.
In actuality the only way around this is to increase the colour precision to 30 bits so that each of the colour components is represented by 10 bits. This increases the total number of colours and reduces the size of each colour dot to solve gradient related issues detailed above.
Another issue comes into play however because even though graphics cards have supported this transfer of 30 bit colour via DVI for a long time this is really not a widespread feature. Very few monitors to this point even handle a 30 bit interface without even bringing the software into play.
If you are working with colour and software, the graphics card and monitor both have to operate with formal numbers, from 0 to 255 for each of the basic colours. (0, 0, 255) for example corresponds to blue. This is easily seen if you open the Photoshop colour palette and key these digits into the RGB radio entries.
Problems occur however when you view the same numbers on various panels because they will almost always look different to the naked eye. An extended gamut monitor for example will have a purer colour than a standard consumer screen. When I say “purer” incidentally I mean more saturated. Running a monitor side by side is a clear way to see this and the standard screen will show generally a colour hue overlaying the actual colour, such as yellow, over green.
The transformations of formal number values into a physical value seen by the naked eye is performed by the monitors LCD matrix. These matrixes are variable whereas the software is mostly oriented to one configuration with the same standard called sRGB.
Due to this, monitors with an extended colour gamut, an extended relative to the standard sRGB gamut will distort colours when they are displaying sRGB embedded images prepared in sRGB software. The monitor attempts to “stretch” the sRGB image to fit within its own gamut. This is even more problematic when not only colours but halftones shift.
Pixel-Response rate: 6ms
Contrast Ratio: 1,000:1
Brightness: 400 cd/m2
Connectivity: DVIx2, HDMI, VGA, DisplayPort, Component, Composite
HDCP Compliant?: Yes
Included Cables? DVI, Displayport and VGA
Backlight Type: CCFL
Panel Type: H-IPS
Aspect Ratio: 16:10