Toshiba LCD

Introduction

I have had quite a bit of experience with the Toshiba Regza line of LCD flat panels in recent years. What I have found has left me with something of a sour taste in my mouth.

These displays have what appear to be some attractive and useful features from a calibration perspective. For example, they have white balance controls in the user menu (always appreciated) and, more importantly, they boast a full-featured color management system (CMS) that independently adjusts the hue, saturation, and brightness of all six of the primary and secondary colors. Toshiba labels this CMS with the impressive title of ColorMaster Pro.

Basic Performance

First the good news. As with most LCD flat panels, the Regzas offer more than enough brightness. In fact, the first thing you'll probably want to do is turn the contrast down to get it between 35-50 fL. Second, after setting brightness with a pluge pattern, the black level—while not great—are certainly acceptable and much better than what LCDs offered just a couple of years ago. I got 1257:1.

One user menu control is quite useful is the static gamma adjustment. Experimenting with this preset, I was able to obtain a very flat gamma in the desired range.

The panel also delivers on the full 1080p resolution it is capable of. Thus, post-calibration, the image is sharp, bright, and with reasonable depth. So what's the problem?

Color Performance

To begin with the white balance controls offered in the user menu are (strangely) for blue and green only. Moreover, they operate over the entire range of the gray scale and they have relatively limited range of adjustment. In short, even with the most accurate color temperature preset selected, the user menu custom white balance controls are essentially useless. Fortunately, the gray scale was not too far off to begin with and the Regza offers a full set of white balance controls in the service menu. So with a little additional effort, you can get very good gray scale performance from this display.

The bigger problem is with the ColorMaster Pro CMS. The default color performance is, to put it mildly, not great.

The red primary is reasonably good, but blue is undersaturated and shifted towards green. The big problem is that green is grossly bluish and oversaturated, which throws cyan considerably off as well. As you can see in the CIE chart above, calibration did not improve either very much, and the reason is that the ColorMaster CMS is something of a disaster.

CMS's generally suffer from two types of flaws. First, and more benign, they can lack the requisite range of adjustment. They allow the calibrator to improve the color somewhat, but not to completely fix it. Second, and much more troubling, they can have unwanted interactive effects. The CMS in the Pioneer Elite plasmas is a good example of the second type of problem. Use the CMS and it substantially changes the white balance of the panel.

The Regza does not lack a sufficient range of adjustment, but it is plagued by a similar problem to the Pioneers. When you use the provided controls to try to bring the green primary closer to its target, this has the effect of lowering its brightness, which was too low too begin with. The appropriate response to this is to use the brightness adjustment in the CMS to correct this problem. Here's where the Regza lost me. Increasing the brightness of a color even a little imparts a very visible and unacceptable level of noise to the image. The color becomes more accurate, but the overall image quality becomes much worse. In the end you are better off just leaving the color in its default state, the performance of which is shown below in the dE chart. I was able to improve red simply by lowering the main color control a little. The secondaries were improved by improved gray scale tracking and small adjustments to the hue controls in the CMS. Otherwise, I left all of the ColorMaster Pro settings at the default values.

These numbers are in CIE94, which has a maximum acceptable post-calibration error level of 1.5. As you can see, the errors in green, blue, and cyan are enormous. The green error is about the largest I have ever seen. It is even larger than the JVC RS1/2 front projector, which used to be the champ in this dubious category. Yellow and magenta are not too bad. Only red offers excellent performance. This is important because red is critical to the display's ability to correctly portray skin tones, to which the eye tends to be very sensitive.

Conclusion

Post-calibration, provided you don't try to fix the color errors by using the ColorMaster Pro, the Regzas look reasonably good. As I said at the outset, the image is bright, sharp, and with good resolution. Furthermore, because of the good gray scale tracking and accurate red primary, skin tones look good as well. The problem is that the other color errors on this display are just too large in my opinion to be acceptable in the current market. For example, a similarly-priced Samsung LCD, offers all of the benefits of the Regzas in addition to which you get a lower black level and much, much better color performance. For this reason, I can't recommend this display.