Follow-up: Panasonic plasma black-level loss measured in long-term test
CNET's long-term test of two in-house Panasonic plasmas has revealed a black-level rise, impairing picture quality somewhat, after a certain number of hours of use.
Previousof Panasonic plasma TVs measured differences in black-level performance seemingly related to the age of the televisions. New results from our follow-up testing further confirms that relationship.
On January 26, after we heard about the
The latest measurements of the V10 reveal a black level of 0.016 footlamberts at 982 hours of use, compared with the 0.008 we measured previously. Black on the S1 measures 0.017 after 1,012 hours, compared with a previous 0.011.
These results are similar to increases we measured on a TC-P50G10 and a TC-P42G10. Neither was aged under controlled conditions in our lab, but both reproduced black at 0.023 ftl after about 1,500 hours (at the average rate of 5.2 hours per day, a TV logs about 1,900 hours in a typical year). We suspect that more aging of our two in-house models will result in similar rates of increase, but only further testing will tell.
In comparison, the deepest black levels we've recorded are 0.001 ftl--as low as our Konica Minolta LS-100 meter will accurately measure--seen on models like the
Panasonic has indicated that it has modified itsto introduce a "more gradual change in black level over time." We have yet to test any 2010 Panasonic plasma--the company promises to deliver a review sample in the next couple of weeks--but when we do we will also conduct long-terms tests as best we can. We are also exploring a long-term test regimen for other TV products, but can't promise anything yet.
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