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Discussion Starter · #1 ·

This group was very helpful in helping me diagnose a light tunnel problem in my 3 year old Samsung HL-R6178. Thank you. Even though the set was 3 years old Samsung agreed to replace the light tunnel at not charge. I thought that at the same time I would have the technician replace the bulb which I figured was slowly fading, although it was not obvious to me.

Well, the technician came Friday and replaced the light tunnel and the bulb. Unfortunately, the replacement light tunnel was defective, so it will have to be done again.

But the purpose of this post was to present a little unscientific test I did about the benefit of the bulb replacement. The bulb replacememnt will cost me about $200.

With the room dark I took EV measurments of a "source" blue screen with a Sekonic Light meter. I did EV measurments directly touching the screen and then 3 feet back measuring with a yardstick. The lightmeter was set to an ISO of 100 and I used reflected measuring. The data is in EV f(exposure value) for the three factory modes in my Samsung TV; Dynamic, Standard and Movie. The old bulb data is first followed by the data for the new bulb with a slash in between.

Dynamic -Touching Screen 6.4/8.1 Three Feet Away 6.3/7.9

Standard -Touching Screen 6.1/7.7 Three Feet Away 6.0/7.5

Movie -Touching Screen 5.0/6.6 Three Feet Away 4.9/6.4

Again, this is NOT scientific, but is something that I had the opportunity to do since I knew in advance I was changing a bulb. You guys all know this, but it just showed that bulb brightness does get less with time. The decrease in brightness is very slow so you may not even notice it.

The TV does look better now, except that I need another exchange of the light tunnel to remove the edge artifact.

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