Olevia 747i LCD 1080p Television Tests and Calibration

Tests and Calibration

The Olevia 747i's black and white (luminance) and color response, in both HDMI and component, extended up to the maximum burst frequencies from my AccuPel HDG-3000 test pattern generator at all resolutions (6.75MHz for 480i, 13.5MHz for 480p, and 37.1MHz for 720p and 1080i). The result with the 1080i burst, in particular, was as good any we have seen from a display of any description, including front projectors.

With HDMI at 480i, the set did not respond properly to the generator- the patterns were visible, but enlarged and off-center. This was odd as the Olevia did respond properly to a 480i HDMI output from my Pioneer Elite DV-79AVi DVD player.

The set looked excellent on sharpness patterns at all resolutions, with single pixel lines crisply resolved where present, particularly at the high-definition resolutions. The minimum setting of the Sharpness control was optimum, though its action was mild, and an increase to a setting as high as 50% did not result in serious artifacts on normal program material.

But there was one odd result, which is shown in Figs. 1 and 2. With 1080i HDMI (Fig.1), all the horizontal lines in the sharpness pattern were accompanied by additional, one pixel-width horizontal lines. As you can see, these "phantom lines" were as crisp as the lines in the pattern itself, and not the sort of shadowy lines you would see with ringing. They were also visible from other AccuPel 1080i HDMI test patterns having sharp horizontal edges.

Fig. 1

Fig. 2

The same 1080i pattern is shown in Fig.2 as reproduced through an HDMI connection to the Sony VPL-VW50 ("Pearl") 1080p projector. This is what it should look like. It's possible that there is some incompatibility between the AccuPel generator at 1080i and the Olevia. I saw no sign of this artifact in any other situation, including normal 1080i program material via HDMI, test patterns in 1080i component, or any type if source at other resolutions.

The primary RGB color points on the Olevia were very close to ideal. Green was off the most, but far less oversaturated than most modern digital displays we measure. The secondary color points for cyan and magenta were off a bit more (though yellow was excellent), but not enough to make an issue over.

In its 6500K color temperature setting, the pre-calibration gray scale (measured with our Photo Research PR-650 colorimeter), was very close to the ideal temperature (see the chart). But there was a bit too much green in the readings, something that the color temperature numbers alone do not show. A slight recalibration in the 6500K User menu brought the x/y coordinates closer to the D6500 standard (x=0.313, y=0.329 on the CIE color chart across the full brightness range).

I measured a peak contrast ratio of 915:1 (72.32 foot-Lamberts peak white, 0.079fL video black). This is lower than the specified Dynamic Contrast of 1600:1, but it isn't clear what Olevia means by Dynamic Contrast. My measured 915:1 peak contrast ratio is better than other flat panel displays I have tested recently (including the Sony and JVC, mentioned earlier), but the Olevia's black level was worse (higher) than on those other displays.

Overscan averaged about 1% or less at all resolutions, in both HDMI and component. A cropping control is provided to increase this to about 3.5% in case noise or other artifacts intrude at the edges of the picture. But engaging the cropping control does affect resolution. The difference is most evident at 1080i. Fig.3 shows multibursts at 18.5MHz (left) and 37.1MHz (right) without cropping. Fig.4 shows the same two bursts with cropping engaged.

Fig. 3

Fig. 4

It is not uncommon for such overscan/cropping controls to affect resolution So this is less a criticism of the Olevia than a caution against using its Cropping control unless it is needed to eliminate the noise that occasionally turns up at one or more edges of an image.

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