iDTV sets are more and more versatile these days. Apart from the standard feature of internal digital TV tuner, some also offer recording function and even 3D effect. But a test revealed that their performance varied vastly on different functions, consumers should compare carefully before making the purchase.
The Consumer Council has commissioned a specialized laboratory in Germany to conduct a performance test on 20 models of iDTV sets, 15 of them with 42-inch screen while 5 with 40-inch screen. Their retail prices ranged from HK$3,999 to HK$18,380.
17 samples used LED (Light Emitting Diode) backlight LCD display, 2 used CCFL (Cold Cathode Fluorescent Lamp) backlight LCD display, and the remaining one was of Plasma display.
The test evaluated the samples on picture quality, sound quality, ease of use, recording, versatility, special feature and energy efficiency. Highlights of the results are:
- 5 samples were found to have serious screen reflection problem due to their glossy display design. Users might need to close the curtain or adjust the room lighting when using these sets. In a similar test last year, only one out of 20 samples presented such problem.
- 4 samples offered 3D effect, but with varied performance. Problems detected included flickering, crosstalk and grainy images. Only one sample scored full mark in its 3D effect. All 4 samples required users to wear either active shutter or passive polarizer 3D eye-wears in order to see the effect. The former eye-wears were of more complicated design, weighed from 35g to 58g and priced from HK$680 to HK$1,280. The latter was much lighter at about 15g and usually sold under HK$25.
- The sound quality of most samples was not satisfactory, probably due to the limitation of the very thin housing design where only weak speakers could be accommodated.
- Majority (17) of the samples had video recording function providing instant or timer recording. Some were of more flexible designs, for instance during the time of recording, those models allowed switching to other channels of the same broadcast frequency, or playing back of old recordings.
- The majority of samples performed well on contrast and brightness testing.
- On energy efficiency, the annual running cost would range from HK$124 to HK$495 assuming daily stand-by mode of 20 hours and 4 hours of watching. The annual running cost of 7 samples would be below HK$160 a year. One sample was unable to operate timer recording on true standby mode - when its timer recording was set, the standby power consumption was as high as 26 watt.
Consumers are advised to take note of the following green tips when using iDTV:
- For better maintenance of the TV, clean the set regularly according the instructions to prevent dust from gathering.
- Turn off the power supply instead of using standby mode if the TV is not to be in use for long period of time.
- Consider using re-chargeable battery when it is time to replace the battery of remote control.
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