CurtPalme.com Home Theater Forum

[mookee]

[CasetheCorvetteman]

If you dont ask a specific question youre very unlikely to get any sort of specific response.

[mookee]

okay; than on a nec 6 pg plus please. i thought its a nonspecific question, like crts have this in common... but yeah, please consider my device..

bw christoph

[gjaky]

I would suggest to set up your machine to the point where the full white and small area white pattern looks equally bright, in other words where there is no difference between peak and ansi lumen output.

[kal]

Afraid this question doesn't really make any sense, because:

(1) The max contrast depends on many factors including the screen gain, the size of the bright spot you're lighting up on the screen as 100% white (the smaller the spot the brighter it will be on CRT projectors and plasma displays as these devices are voltage limited - in other words, a full screen showing 100% white will not be as bright when measured as compared to small area).

(2) Brightness is your black level. You set it correctly to make black appear black. I don't understand what you mean by "maximum" brightness level. Contrast is light output.

If you tell us what you're trying to do, why you're asking, we can probably help.

Kal

[kal]

Afraid this question doesn't really make any sense, because:

(1) The max contrast depends on many factors including the screen gain, the size of the bright spot you're lighting up on the screen as 100% white (the smaller the spot the brighter it will be on CRT projectors and plasma displays as these devices are voltage limited - in other words, a full screen showing 100% white will not be as bright when measured as compared to small area).

(2) Brightness is your black level. You set it correctly to make black appear black. I don't understand what you mean by "maximum" brightness level. Contrast is light output.

If you tell us what you're trying to do, why you're asking, we can probably help.

Kal

[Curt Palme]

Also, the higher the contrast, the shorter the tube life, and since NECs are very sharp projectors, the tubes don't last too long in the first place.

To give you an idea, when I was installing Zenith PRO 851s in sports bars, the typical life at 14 hour a day use 7 days a week was about 2.5 years. Most bar owners didn't change the tubes until the 3.5-5 year mark, at which point the pictures looked TERRIBLE!

One bar owner had me install a projector into his bar where there was direct sunlight shining on the screen from a series of small windows over the bar. I told him that he had to black out those windows, or the projector image would look bad. He called me a year later to come check out the projector, that the picture was terrible.

When I got there, of course he never tinted out the windows, and the brightness and contrast were set to 100. It cost him $2500 for me to retube it.. .NOT under warranty. He had the windows tinted out by the time I came back with tubes.

[Curt Palme]

Also, the higher the contrast, the shorter the tube life, and since NECs are very sharp projectors, the tubes don't last too long in the first place.

To give you an idea, when I was installing Zenith PRO 851s in sports bars, the typical life at 14 hour a day use 7 days a week was about 2.5 years. Most bar owners didn't change the tubes until the 3.5-5 year mark, at which point the pictures looked TERRIBLE!

One bar owner had me install a projector into his bar where there was direct sunlight shining on the screen from a series of small windows over the bar. I told him that he had to black out those windows, or the projector image would look bad. He called me a year later to come check out the projector, that the picture was terrible.

When I got there, of course he never tinted out the windows, and the brightness and contrast were set to 100. It cost him $2500 for me to retube it.. .NOT under warranty. He had the windows tinted out by the time I came back with tubes.

[ElTopo]

My Barco runs with about 38 in brightness and 75 in contrast.

Tubes are brand new.

The Barcos i had in the past had more or less the same level.


With tubes running > 10.000 hours it changes i think

[CasetheCorvetteman]

[CasetheCorvetteman]

[mookee]

no case, thats actually what i ment. how far can you go to not destroy it within unreasonable time.. ,kind of like curts story..

[CasetheCorvetteman]

100 and 100 if you like, it depends on a ton of other variables.

It depends on the source
It depends on the screen type
It depends on the screen size
It depends on the room suroundings
It depends on the ambient lighting conditions
It depends on the tube condition
It depends on the kelvin settings
It depends on cables used and their length and quality
It depends how many items are in the signal path
It depends on the lenses used
It depends on beam focus
It depends on the condition of the glycol
It depends whether someone has molested the internal pots
It depends on the condition of all internal components
It depends whether you prefer Mobil 1 or Castrol Synthetic
It depends on the projector operating temperature
It depends on the CRT drive mode selected

Someone will probably come along and add ten more variables.

The brightness and contrast settings are NOT a constant, they are very much a variable. Set them however the f*** you like

[gjaky]

[Curt Palme]

Well, despite the sarcasm, Case's list is pretty much accurate. There's really no 'real' way to determine how hard and how long you can run a tube at greater than normal brightness.

Two more variables:

-run both as low as possible for maximum tube life.
- if you consider your CRT to be a disposable item at this point, run as high and as hard as you want, since you won't be spending money repairing it.

[Curt Palme]

Well, despite the sarcasm, Case's list is pretty much accurate. There's really no 'real' way to determine how hard and how long you can run a tube at greater than normal brightness.

Two more variables:

-run both as low as possible for maximum tube life.
- if you consider your CRT to be a disposable item at this point, run as high and as hard as you want, since you won't be spending money repairing it.

[Zolzar]

I'm currently running at Curt's second suggestion.....run it hard baby! I'm running the contrast at about 75 on my PG10 which in my scenario is just before full white starts to bloom. I figure I only have 1K hours on the tubes at this point so what he heck.....enjoy it and when they are completely toasted on the I'll go back to the M8500. Of course all of this will change this weekend when I further simplify the video chain and loose the Extron which is really no longer needed and isn't really doing anything except shifting the image which I don't really need either.

[CasetheCorvetteman]

There was no sarcasm in it with the exception of the engine oils thrown in there, the rest is just plain and straight forward.

At the end of the day, people can take the written word any way they like, and if you want to take it to heart Gábor that is your problem buddy, im not sugar coating anything for anyone

I dont take anything so seriously as to get uptight about the way someone chooses to present their free help, i just wouldnt bother losing sleep over something so insignificant.

[CasetheCorvetteman]

[mookee]

thanks to all! i guess i can picture it now.. @zolzaz: HAHA;

[CasetheCorvetteman]

Basically run it however you like, you never know how long itll last before it takes a dive. Its now over 20 years old.

[pm]

My approach has been to leave;

Brightness=50
Contrast=75

And then make fine adjustments with a test card up via the video card, in my case AMD Vision.

How else do people do this? Am I missing a better way perhaps?

Cheers,

Paul

[kal]

[kal]