[Viking2000]

I went to the movies last night to see Planet of the Apes. Before I became interested in HT I never thought about contrast or blacklevel in movie theaters. Last night I realized that black isn't black in movie theaters either. So does anyone know what the contrast and lumens is in a decent movie theater, when they have all lights off? I realize it can vary, but still.. would be interesting for comparison.

 

[Frank J Manrique]

Vicking2000,


If you mean black level isn't as velvety deep as with CRT display devices (providing brightness is properly calibrated and correctly set, of course), yeah...that is right. After all, a light source "push" through the film emulsion to project an image onto a screen.


However, reproduction of blacks can't be any better than with film! This fact even shows on video. For example, check the Singing In The Rain DVD and feast your eyes with the sort of blacks 3-strip dye transfer Technicolor were able to produce...absolutely majestic! Modern IB Tech, Fuji, Kodak LPP and even older Eastman film stocks are also very capable in the reproduction of blacks.


Film's contrast dynamic range is so vastly superior to any video format extant as to defy description; there just isn't any comparison...


As for the matter of brightness in cinema houses, so long as xenon lamps are adequate in output (3000 watts and higher) there should be no reason for dim images.

I'll now cede the floor to Vern Dias to give us more technical specifics related to theatrical brightness standards, but I'll hazard a guess and say ideally around 16 foot Lamberts. Vern, what do you say? http://www.avsforum.com/ubb/smile.gif


-THTS

 

[Vern Dias]

I'll say 16 fl is about right. The SMPTE has specific standards for light output in theaters.


The issue with xenon lamps in movie theaters is that a new lamp puts out much more light than one that has a thousand hours on it.


Back in the good old days http://www.avsforum.com/ubb/wink.gif when carbon arc was the standard, a properly adjusted lamphouse always delivered a consistent brightness to the screen.


When we first started using xenon lamphouses, and we had real projectionists http://www.avsforum.com/ubb/wink.gif , we would start a new xenon lamp at a lower amperage and gradually increase the amperage as the bulb aged to make up for the reduced light output that was a result of the bulb's envelope darkening.


Today, unless you live in LA or NY, all bets are off regarding the proper setup of most theaters.


Too much light is as bad as too little, causing visible flicker on bright scenes and poor black levels.


However, the problem in many theaters is light spill on the screen from exit signs and other external sources. Many theaters also leave the house lights on at a very low level, or have wall sconces on at a low level, because after all no one wants to be sued by a patron who trips or otherwise injures him/herself.


I feel that I have better light control in my home theater that most commercial theaters have.


Vern
http://members.home.net/tvdias/

 

[Viking2000]

Ok, thanks. I think we must have good theaters in Sweden, I never saw any dim or flickering movies over here. Do CRT projectors beat the black level of film projectors?

 

[JATWolf]

Another thing to consider is the movie you saw. Tim Burton likes to shoot everything in a sort of dark haze it seems. I saw Planet of the Apes in the theater and completely agree about the black levels. It seemed at times like it was washed out and gray looking. It was just the movie itself I think. It didn't help that the movie sucked and I found myself checking out the picture quality more than usual!