# Vibrations and projector lamp life **URL:** \ **Category:** Factual Questions\ **Created:** [November 7, 2005, 4:10pm UTC](https://boards.straightdope.com/t/vibrations-and-projector-lamp-life/329917 "2005-11-07T16:10:57Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Nature\_s\_Call](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/nature_s_call/32/19006_2.png) [@Nature\_s\_Call](https://boards.straightdope.com/u/Nature_s_Call)\ **Post date:** [November 7, 2005, 4:10pm UTC](https://boards.straightdope.com/t/vibrations-and-projector-lamp-life/329917/1 "2005-11-07T16:10:57Z")
I have a home theatre DLP projector mounted onto the ceiling of the family room in the basement. This ceiling is the floor of the living room above it. When watching a movie while the kids are stomping around upstairs, there is a noticable jiggle to the projected image. My question: Is this affecting the longevity of my lamp’s life? It’s supposed to last 5000 hours. If this stomping is shortening it, by how much would you expect it to be shortened? ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [November 7, 2005, 4:36pm UTC](https://boards.straightdope.com/t/vibrations-and-projector-lamp-life/329917/2 "2005-11-07T16:36:05Z")
Probably not all that much. Projector lamps are high wattage and, as such, they have a fairly thick and heavy filament. These tend to be less prone to vibration failure than thinner, low-wattage filaments. I wouldn’t worry too much about it. ---
**Author:** ![Harmonious\_Discord](https://avatars.discourse-cdn.com/v4/letter/h/74df32/32.png) [@Harmonious\_Discord](https://boards.straightdope.com/u/Harmonious_Discord)\ **Post date:** [November 7, 2005, 4:45pm UTC](https://boards.straightdope.com/t/vibrations-and-projector-lamp-life/329917/3 "2005-11-07T16:45:49Z")
It’s bad for the lamps and for the projectors focusing mechanisism. ---
**Author:** ![gotpasswords](https://avatars.discourse-cdn.com/v4/letter/g/c57346/32.png) [@gotpasswords](https://boards.straightdope.com/u/gotpasswords)\ **Post date:** [November 7, 2005, 7:56pm UTC](https://boards.straightdope.com/t/vibrations-and-projector-lamp-life/329917/4 "2005-11-07T19:56:34Z")
It’s certainly not going to extend the life of the lamp. There’s no easy way to say that the stomping will take X hours of life off the lamp, but eventually, the shock will act on a weak spot in the filament and \ Just tell the kids that if the projector fails because they’re acting like elephants upstairs that the new lamp will be coming out of their allowance. Why aren’t they downstairs enjoying the big-screen movie, anyway? ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [November 7, 2005, 10:37pm UTC](https://boards.straightdope.com/t/vibrations-and-projector-lamp-life/329917/5 "2005-11-07T22:37:22Z")
> [@Q.E.D.](#): > > Probably not all that much. Projector lamps are high wattage and, as such, they have a fairly thick and heavy filament. These tend to be less prone to vibration failure than thinner, low-wattage filaments. I wouldn’t worry too much about it. FWIW, I read somewhere that filament-type bulbs (e.g. incandescent) are less vulnerable to shock & vibration when they’re _on_ vs. off. This is because the filament becomes plastic (I’m using this term as an adjective) at a very high temperature, and is thus less brittle. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [November 7, 2005, 10:54pm UTC](https://boards.straightdope.com/t/vibrations-and-projector-lamp-life/329917/6 "2005-11-07T22:54:31Z")
> [@Crafter\_Man](#): > > This is because the filament becomes plastic (I’m using this term as an adjective) at a very high temperature, and is thus less brittle. I think that’s true of most, if not all, metals, isn’t it? It’s why blacksmiths work steel while red hot, rather than at room temperature. Are there any metals which actually get _more_ brittle as they heat up? ---
**Author:** ![danceswithcats](https://avatars.discourse-cdn.com/v4/letter/d/9e8a1a/32.png) [@danceswithcats](https://boards.straightdope.com/u/danceswithcats)\ **Post date:** [November 7, 2005, 11:10pm UTC](https://boards.straightdope.com/t/vibrations-and-projector-lamp-life/329917/7 "2005-11-07T23:10:23Z")
> [@Q.E.D.](#): > > I think that’s true of most, if not all, metals, isn’t it? It’s why blacksmiths work steel while red hot, rather than at room temperature. Are there any metals which actually get _more_ brittle as they heat up? Most of us, as kids (and occasionally as adults) have banged into a lamp and noted that the brilliance increased, quickly followed by lamp failure. While it’s no big deal for a 60W soft white lamp, I’d get out the Homeland Security duct tape for activity that causes premature killing of a projector lamp. 😉