# Do they really turn off a theatrical movie if there's nobody watching? **URL:** \ **Category:** Cafe Society\ **Tags:** movies\ **Created:** [November 13, 2025, 3:12am UTC](https://boards.straightdope.com/t/do-they-really-turn-off-a-theatrical-movie-if-theres-nobody-watching/1024821 "2025-11-13T03:12:15Z")\ **Posts on this page:** 11\ **Page:** 3
**Author:** ![JKellyMap](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jkellymap/32/15880_2.png) [@JKellyMap](https://boards.straightdope.com/u/JKellyMap)\ **Post date:** [November 19, 2025, 12:10pm UTC](https://boards.straightdope.com/t/do-they-really-turn-off-a-theatrical-movie-if-theres-nobody-watching/1024821/41 "2025-11-19T12:10:15Z")
> [@DesertDog](#): > > At least some of the adjacent theaters had a system of rollers overhead so the film could be carried to the other theater if they wanted to interlock – show the film in more theaters than they had prints. That amazes me! Makes sense, though. ---
**Author:** ![minor7flat5](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/minor7flat5/32/258_2.png) [@minor7flat5](https://boards.straightdope.com/u/minor7flat5)\ **Post date:** [November 19, 2025, 12:25pm UTC](https://boards.straightdope.com/t/do-they-really-turn-off-a-theatrical-movie-if-theres-nobody-watching/1024821/42 "2025-11-19T12:25:32Z")
> [@JKellyMap](#): > > That amazes me! Check out the second of those two videos I posted above–the “strut their stuff” one–I explain all about how interlock works and show some video clips of crazy interlock setups. ---
**Author:** ![JKellyMap](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jkellymap/32/15880_2.png) [@JKellyMap](https://boards.straightdope.com/u/JKellyMap)\ **Post date:** [November 19, 2025, 12:26pm UTC](https://boards.straightdope.com/t/do-they-really-turn-off-a-theatrical-movie-if-theres-nobody-watching/1024821/43 "2025-11-19T12:26:50Z")
I will, right now! ---
**Author:** ![JKellyMap](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jkellymap/32/15880_2.png) [@JKellyMap](https://boards.straightdope.com/u/JKellyMap)\ **Post date:** [November 19, 2025, 1:21pm UTC](https://boards.straightdope.com/t/do-they-really-turn-off-a-theatrical-movie-if-theres-nobody-watching/1024821/44 "2025-11-19T13:21:22Z")
That was wonderful. Could you hear each theater’s crowd scream in sequence, as the famous bathtub scene in _Fatal Attraction_ wound past their projector? ---
**Author:** ![minor7flat5](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/minor7flat5/32/258_2.png) [@minor7flat5](https://boards.straightdope.com/u/minor7flat5)\ **Post date:** [November 19, 2025, 1:25pm UTC](https://boards.straightdope.com/t/do-they-really-turn-off-a-theatrical-movie-if-theres-nobody-watching/1024821/45 "2025-11-19T13:25:32Z")
Nope. Everything was soundproof. Imagine having to listen to the babble of multiple theaters all running different films…and imagine being in the theater hearing the clatter of a projection booth. ---
**Author:** ![Just\_Asking\_Questions](https://avatars.discourse-cdn.com/v4/letter/j/ba9def/32.png) [@Just\_Asking\_Questions](https://boards.straightdope.com/u/Just_Asking_Questions)\ **Post date:** [November 19, 2025, 2:21pm UTC](https://boards.straightdope.com/t/do-they-really-turn-off-a-theatrical-movie-if-theres-nobody-watching/1024821/46 "2025-11-19T14:21:39Z")
> [@minor7flat5](#): > > Nope. Everything was soundproof. I was going to ask this earlier: so the movie is shown through a glass window, then? I always figured it was shown with nothing between the lens and the screen. There’s never a problem with degrading the image, or reflections? ---
**Author:** ![JKellyMap](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jkellymap/32/15880_2.png) [@JKellyMap](https://boards.straightdope.com/u/JKellyMap)\ **Post date:** [November 19, 2025, 2:44pm UTC](https://boards.straightdope.com/t/do-they-really-turn-off-a-theatrical-movie-if-theres-nobody-watching/1024821/47 "2025-11-19T14:44:31Z")
> [@minor7flat5](#): > > Nope. Everything was soundproof. Imagine having to listen to the babble of multiple theaters all running different films…and imagine being in the theater hearing the clatter of a projection booth. Got it. Yes, you mentioned in the video (and I think upthread) that you can open a little window to check the sound, from time to time. I thought maybe, just for fun, your projectionist friend opened them in sequence for that particular moment of that film (for those that haven’t seen the video, the largest number of simultaneous interlocked projections by someone minor7flat5 knows personally was five, for _Fatal Attraction_.) Not important. Just a mildly amusing thought. ---
**Author:** ![minor7flat5](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/minor7flat5/32/258_2.png) [@minor7flat5](https://boards.straightdope.com/u/minor7flat5)\ **Post date:** [November 19, 2025, 3:07pm UTC](https://boards.straightdope.com/t/do-they-really-turn-off-a-theatrical-movie-if-theres-nobody-watching/1024821/48 "2025-11-19T15:07:34Z")
> [@Just\_Asking\_Questions](#): > > There’s never a problem with degrading the image, or reflections? Nope. The projector’s light source is seriously powerful (2500W is not unusual) and focused in a tight beam, so it blasts right on through the glass. I suspect it might be something other than ordinary window glass…but maybe not. The windows were double glazed, just like home windows, to block the sound. We did clean the glass, but any dust or smudges on it were so far from the focus plane that they wouldn’t affect the image. ETA: Totally random cool thing about the light path: our lamp houses held the lamp in a vertical position, with a big salad-bowl reflector in the bottom pointing up. At the top was an expensive 45-degree mirror made of some special glass that reflected visible light but let infrared light pass through. There was something that looked like firebrick in the top of the lamp house that absorbed the infrared. The visible light was then reflected out through the film and lens. ---
**Author:** ![ZosterSandstorm](https://avatars.discourse-cdn.com/v4/letter/z/e0b2c6/32.png) [@ZosterSandstorm](https://boards.straightdope.com/u/ZosterSandstorm)\ **Post date:** [November 19, 2025, 3:42pm UTC](https://boards.straightdope.com/t/do-they-really-turn-off-a-theatrical-movie-if-theres-nobody-watching/1024821/49 "2025-11-19T15:42:45Z")
> [@JKellyMap](#): > > That was wonderful. Could you hear each theater’s crowd scream in sequence, as the famous bathtub scene in _Fatal Attraction_ wound past their projector? Maybe not from the booth, but certainly from downstairs - the exit doors to the auditorium aren’t soundproof by any means. Hearing the screeching of the fell beasts move down the hall every 45 seconds during LOTR: Return of the King was a good demonstration of this. > [@minor7flat5](#): > > The projector’s light source is seriously powerful (2500W is not unusual) and focused in a tight beam, so it blasts right on through the glass. I suspect it might be something other than ordinary window glass…but maybe not. It’s high-quality optical glass with coatings designed to make it usable for this purpose. The angle relative to the lens is also important, to control where reflections end up. It needs to be cleaned pretty diligently too, though less so now than when film-based machines were spewing a mist of lubricating oil everywhere. ---
**Author:** ![DesertDog](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/desertdog/32/11503_2.png) [@DesertDog](https://boards.straightdope.com/u/DesertDog)\ **Post date:** [November 19, 2025, 4:28pm UTC](https://boards.straightdope.com/t/do-they-really-turn-off-a-theatrical-movie-if-theres-nobody-watching/1024821/50 "2025-11-19T16:28:31Z")
Part of the [THX certification](https://www.thx.com/thx-certified-cinema/) – the multiplex I’ve been talking about is – covers soundproofing so you don’t get any bleed between theaters. The story is Lucas was in a theater watching a revival of _American Graffiti_ and during the quiet parts the noisy film next door bled through. This vexed him. ---
**Author:** ![minor7flat5](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/minor7flat5/32/258_2.png) [@minor7flat5](https://boards.straightdope.com/u/minor7flat5)\ **Post date:** [November 19, 2025, 4:59pm UTC](https://boards.straightdope.com/t/do-they-really-turn-off-a-theatrical-movie-if-theres-nobody-watching/1024821/51 "2025-11-19T16:59:27Z")
When we were showing “Born on the Fourth of July” it was in our largest theater, with the best audio rack, and it sounded great. One evening I was looking though the little window to make sure things were in order (framing and focus) and I noticed some unusual patterns that looked like ripples in a pond all over the screen. This intrigued me. I soon discovered that somebody had CRANKED the volume, and during a particular battle scene the battle sounds were so loud that the speakers were causing pond ripples in the screen (the main speakers for a movie theater are directly behind the screen, and the screen is filled with millions of tiny holes). All of the boom and clamor was completely blocked out by the soundproofing, both upstairs and downstairs. I walked into the theater and was blown away, feeling like that “Live or Memorex” guy in the chair. Nobody complained though. I slowly lowered things to a more sane level. [Previous page](https://boards.straightdope.com/t/do-they-really-turn-off-a-theatrical-movie-if-theres-nobody-watching/1024821.md?page=2)