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281 Posts

12-08-2008

United States of America

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P50 - easiest way to test brightness?

2016-07-22, 21:40 PM

basic question, what would be the easiest (e.g. cheapest) way to me to measure the brigthness of my P50 panel? (btw, I have not found a way to identify the manuf. of the panel, when people quote it is Sharp is because they opened the chasis and saw a label?)

 

 

Moderator comment: Model added to subject for clarity.

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125 Posts

01-30-2016

Denmark

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Re: P50 - easiest way to test brightness?

2016-07-23, 19:16 PM

Forgot to say that the colorimeter must also be suitable for LED backlight types. Older types designed for CRT or CCFL do not work reliably, and they might show incorrect light output.

 

It is always worth complaining, if it bothers you. I don't know what Lenovo's requirements actually are, but for legal matters they better test it according to the manufacturer's tolerances and measurement methods. I don't have the datasheet for the Sharp panel, but the LG 15.6" 4K screen LP156UD1-SPA2 can be found on the net. The typical brightness is 300 nits. Minimum guaranteed is 255 nits. And these values are even based on an average of 5 samples, measured perpendicular to the display using a spectrophotometer placed 50 cm away.

 

The reason why the 4K Sharp panel looks dark is due to the kind of absurd viewing angles, so everything not perpendicular with your eyes loses brightness. But I don't think there's any requirement regarding the severity of this anywhere. Except that viewing angles are defined as the angle at which the contrast ratio reaches 10:1.

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125 Posts

01-30-2016

Denmark

237 Signins

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  • Posts: 125
  • Registered: ‎01-30-2016
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  • Message 2 of 4

Re: P50 - easiest way to test brightness?

2016-07-23, 18:01 PM

The easiest and cheapest would still be with a colorimeter. Just for measuring the brightness, some sort or Spyder from Datacolor would do, also used/second-hand. Just don't rely on it for calibration purposes regarding color primaries.

 

I don't think anyone opened up the LCD bezel, but that would of course also help identifying the panel model :D

But other than that, the display model is written into the EDID, which is stored in the display panel itself. This EDID can be retrieved and interpreted by various software. You can for example download the trial version of Aida64 Extreme: http://www.aida64.com/downloads . When it is installed and started, go to the Display -> Monitor in the left pane. After this the panel model details should be shown in the right pane. :smileyhappy:

 

EDIT: The other reason why people tell you it is a Sharp panel is because there are no other manufacturers for the 15.6" 4K panel in the P50. There's only one FRU/PN number.

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281 Posts

12-08-2008

United States of America

538 Signins

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  • Posts: 281
  • Registered: ‎12-08-2008
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Re: P50 - easiest way to test brightness?

2016-07-23, 18:12 PM

Many thanks. Will check right away.

 

btw if I were to measure substantially less then 300 nits as advertised, would Lenovo accept it as something suitable for repair/replacement of the panel I guess?

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125 Posts

01-30-2016

Denmark

237 Signins

2152 Page Views

  • Posts: 125
  • Registered: ‎01-30-2016
  • Location: Denmark
  • Views: 2152
  • Message 4 of 4

Re: P50 - easiest way to test brightness?

2016-07-23, 19:16 PM

Forgot to say that the colorimeter must also be suitable for LED backlight types. Older types designed for CRT or CCFL do not work reliably, and they might show incorrect light output.

 

It is always worth complaining, if it bothers you. I don't know what Lenovo's requirements actually are, but for legal matters they better test it according to the manufacturer's tolerances and measurement methods. I don't have the datasheet for the Sharp panel, but the LG 15.6" 4K screen LP156UD1-SPA2 can be found on the net. The typical brightness is 300 nits. Minimum guaranteed is 255 nits. And these values are even based on an average of 5 samples, measured perpendicular to the display using a spectrophotometer placed 50 cm away.

 

The reason why the 4K Sharp panel looks dark is due to the kind of absurd viewing angles, so everything not perpendicular with your eyes loses brightness. But I don't think there's any requirement regarding the severity of this anywhere. Except that viewing angles are defined as the angle at which the contrast ratio reaches 10:1.

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