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Author Topic: Switching off Video projector for short breaks? John Koutsoumis Master Film Handler Posts: 261 From: Melbourne, Victoria, Australia Registered: Aug 2003 posted 10-23-2005 08:15 AM                     Along side 35 & 16MM we run video as well. We hire the theatre out and on most occasions it's video that's used (a Dreamvision dlp 500). Most times between bookings or intermissions there night be 30-40 minutes break. Is it worth switching the lamp off or leaving it on. The reason i'm asking is, how much lamp life do you loose everytime you strike it, is it similar to large xenons? We are on a tight budget and need to get as much life out of the lamp before it becomes unacceptable.  |  IP: Logged Richard May Phenomenal Film Handler Posts: 1057 From: Floral Park, NY USA Registered: Aug 2004 posted 10-23-2005 10:36 AM                     John, we have been running video for over 5 years. I compared the difference between leaving them on and shutting them off in between shows. Over about 3 years of doing that there was about about a 20% reduction of life on the bulbs when we relit them after the intermissions. We leave them on all day now.  |  IP: Logged John Koutsoumis Master Film Handler Posts: 261 From: Melbourne, Victoria, Australia Registered: Aug 2003 posted 10-23-2005 11:29 PM                     Thanks Richard. I thought that would be the case. For the most part i've left it on but sometimes at the insistance of the boss, i'd turn it off.  |  IP: Logged Randy Stankey Film God Posts: 6539 From: Erie, Pennsylvania Registered: Jun 99 posted 10-25-2005 10:02 AM                     I have always gone by the theory that one strike of a lamp is equal to two or three hours of running time. Therefore, if you're going to strike a lamp you might as well leave it burn. I'd rather see a lamp struck once and left on all day than to have it struck up and shut off ten times. Provided you have proper ventillation and temperature control, just shut the dowser or, in the case of a video projector, set it for "No-Show".  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 10-25-2005 02:37 PM                     I used to go by that theory, but after doing some comparisons of my own with Sanyo low-end LCD projectors for preshow material, I found it was indeed better to turn the things off once the movie started. I don't blame the shortened lamp life so much on the striking of the bulb as I do the constantly running fans that would clog up the air filters and cause the unit to overheat. I get better life now by having the automation shut them off during the movie.  |  IP: Logged Randy Stankey Film God Posts: 6539 From: Erie, Pennsylvania Registered: Jun 99 posted 10-26-2005 07:58 PM                     So, sending somebody around to make sure the air vents aren't dusty wouldn't be an option?  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 10-26-2005 09:29 PM                     You do that anyway, but it severely decreases how often they have to be cleaned.  |  IP: Logged Richard May Phenomenal Film Handler Posts: 1057 From: Floral Park, NY USA Registered: Aug 2004 posted 10-26-2005 09:31 PM                     You are both right. The vents would and do get clogged over time. As Randy said though, someone should be sent around to clean them. I clean them once a week. I would not turn them off just for that reason, though. If people can't go around and clean the vents, they should not be using the equipment. Unfortunately, it happens all the time.  |  IP: Logged Phil Blake Jedi Master Film Handler Posts: 558 From: esperance western australia Registered: Nov 2003 posted 10-27-2005 09:37 AM                        We have some interesting facts here . I was recently curious as to the life of LCD projecot globes. We are running a midrange panasonic for screen advertising , it runs for about 5 minutes 4 to 6 times a day all week, automatically turning off with the automation. The manual states lamp life should be about 1200 hours , air filters always cleaned and vents free of dirt build up I just got 250 hours out of the globe before it exploded. My immediate thoughts were the turning on and off all the time. The glode cost $800 AU !!! very costly I thought.  |  IP: Logged Mark Hajducki Jedi Master Film Handler Posts: 500 From: Edinburgh, UK Registered: May 2003 posted 10-27-2005 09:58 AM                     quote: Phil Blake automatically turning off with the automation. Is the automation disconecting the power to the projector or sending a 'turn off' instruction (to allow the bulb to cool properly?) Many video projectors have power saving modes (where the bulb brightness is reduced along with the fan speed). For short gaps this may be a better option than a complete shutdown. Is it worth running video (or slide) adverts for 5 minutes between shows?  |  IP: Logged Richard May Phenomenal Film Handler Posts: 1057 From: Floral Park, NY USA Registered: Aug 2004 posted 10-27-2005 10:46 AM                     Mark, good point about shutting off the power. Most projectors keep the fan running for 5 or 10 minutes after you turn them off to cool the bulb more. Phil, check your manual also to see whether or not it's okay to have the bulb on for that short a period of time. My book says to have it lit for at least 10 minutes before turning it off. We keep them on all day (11 hours) and get on average 1500-2000 hours out of them.  |  IP: Logged Jeff Taylor Jedi Master Film Handler Posts: 601 From: Chatham, NJ/East Hampton, NY Registered: Apr 2000 posted 10-27-2005 12:16 PM                     I've read about studies comparing the lifespan of DLP's to LCD's which supposedly produced problems with color "burn out" on LCD's left on continuously for really extended periods. I believe it was with blue chip fade or burnout specifically (I won't make the obvious comparison to pre-LPP Eastman prints!) and if I recall supposedly happened as early as 2,000 hours. Has anybody run into that, or is it propaganda from the DLP crowd?  |  IP: Logged Richard May Phenomenal Film Handler Posts: 1057 From: Floral Park, NY USA Registered: Aug 2004 posted 10-27-2005 12:23 PM                     2 of our LCD projectors are more than 5 years old. No color problems so far.  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 10-27-2005 12:37 PM                     Mark, a video projector should never simply have it's power cut in the manner that most people handled their slide projectors. You must think I'm some kind of idiot if that's how you thought I wired them up to the automations. I also went into the service menu of my projectors and extended the cooldown time to 15 minutes and set it so the fan runs at 100% speed. I got much better life from doing that over the default settings. Jeff, yes LCD projectors look crappy as time passes. Since it is a gradual thing, most people don't really notice though, but all LCD machines do suffer picture quality the older they get.  |  IP: Logged Phil Blake Jedi Master Film Handler Posts: 558 From: esperance western australia Registered: Nov 2003 posted 10-27-2005 10:39 PM                        The automation is switching the unit to standby mode leaving the cooling fans operational.  |  IP: Logged

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