C-PVA and e-IPS
The year of 2009 was remarkable for users who appreciate monitors with large viewing angles as rather inexpensive monitors with C-PVA and e-IPS (H-IPS) matrixes came to the market. Until that moment, we could only choose from TN-based monitors whose vertical viewing angles are still far from ideal and expensive monitors with S-PVA and S-IPS matrixes (the manufacturers would occasionally roll out inexpensive products with such matrixes, e.g. the Samsung 215TW or the Dell 2007WFP, but those were really rare occasions).
I tested C-PVA matrixes in Samsung’s SyncMaster F2080 and F2380 monitors. Featuring a simpler subpixel structure in comparison with the more expensive S-PVA technology, it doesn’t look any worse to the eye. Moreover, the contrast ratio of C-PVA proved to be record-breaking. Unfortunately, C-PVA had inherited such shortcomings of S-PVA as the tonal shift when viewed at an angle and the loss of details in darks when you are looking directly at the screen. Anyway, C-PVA monitors are perfect for working with design drawings and text as well as for home applications if you don’t mind their rather high response time (it is high with the two mentioned models).
The developers of e-IPS technology also simplified the subpixel structure in comparison with S-IPS, increasing the transparency of the matrix and reducing its manufacturing cost (particularly, because of the reduction in backlight intensity: you need less light to achieve the same screen brightness if the matrix is more transparent).
The main drawback of e-IPS in comparison with S-IPS is that the viewing angles are smaller. When you take a look at an e-IPS matrix from a side, the image will lose its contrast as black turns into gray. On the other hand, there is no tonal shift (as with TN and C-PVA matrixes) and the viewing angles, especially vertical ones, are still much larger than with TN.
By the way, the contrast drop occurring when the screen is viewed from a side can be compensated by means of special correcting film, but as e-IPS matrixes are meant for midrange monitors and this film costs money, most products come without it.
Today, there are a few monitors with e-IPS matrixes at very appealing prices. For example, the 23-inch NEC MultiSync EA231WMi, whose color accuracy and viewing angles are good enough even for processing photographs, will cost you less than $600.
Interestingly, like Samsung with its F series, NEC did not try to achieve a low response time. The EA231WMi has no response time compensation and its real speed is about 16 milliseconds (GtG). This is acceptable for movies and even games, but much slower compared to gaming TN-based products. Another popular e-IPS monitor, the 22-inch Dell 2209WA, is free from that downside, but it has a lower resolution of 1680x1050 as opposed to the EA231WMi’s 1920x1080. Considering the current popularity of HD video, this can be viewed as a drawback already.
Thus, the new C-PVA and e-IPS monitors cannot directly compete with TN-based products because they are 30% to 50% more expensive and generally have a high response time, which makes them less suitable for games. However, the introduction of the new, cheaper types of matrixes has had but little effect on their real parameters in comparison with the expensive alternatives (S-PVA and S-IPS). So, if you want a good monitor with large viewing angles for work or home at a reasonable price and you don’t need a very low response time, the C-PVA and e-IPS models are what you should certainly consider in the first place.
As for choosing between these two types of matrixes, e-IPS technology is somewhat more universal and better in terms of color accuracy whereas C-PVA delivers a higher contrast ratio and costs somewhat less. Thus, C-PVA will be perfect for working with design drawings and text, and e-IPS will be good for processing photographs.