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» Film-Tech Forum   » Operations   » Film Handlers' Forum   » When to strike the Xenon in the morning (Page 1)

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Author Topic: When to strike the Xenon in the morning
Bill Langfield
Master Film Handler

Posts: 280
From: Prospect, NSW, Australia
Registered: Apr 2001

 - posted 08-23-2004 01:50 PM      Profile for Bill Langfield   Author's Homepage   Email Bill Langfield   Send New Private Message       Edit/Delete Post 
My experience at every theatre I've ever worked is that you strike the Xenon 30 minutes
before first session of the day.

The reasons:

1/ Sometimes those Strong X's can be bastards. (Even some Xebex Supers)
2/ Strike the Xenon before amps rack/automation is on to avoid spikes to them.
3/ Allows the bulb to warm and settle.
4/ If the bulb wont strike, you have time to fault find.
5/ If the bulb crapped itself the night before, you have time to replace it.

However the new 'tech' has decided that the Xenon should be struck up by the automation on the last slide, in other words, around 10 seconds before the film hits the sheet.

Is that TOTAL madness? Or is it just me?
Is it not just ASKING for trouble?

That being said, what is the general feeling about WHEN to strike up for the first show of the day?

(Btw, this just ONE of mad ideas this 'tech' is turning the place upside down with)

Hi Barry, this post was for you. I was glad you called tonight, your the BEST theatre installer/technician in the country. And stop lurking, sign up.

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Jeremy Fuentes
Mmmm, Dr. Pepper!

Posts: 1168
From: Corpus Christi, TX United States
Registered: Jan 2004

 - posted 08-23-2004 01:57 PM      Profile for Jeremy Fuentes   Email Jeremy Fuentes   Send New Private Message       Edit/Delete Post 
Okay, maybe I'm confused, but are you saying that you strike the Xenon early, and just let it sit on for however long without the projector running??

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Bill Langfield
Master Film Handler

Posts: 280
From: Prospect, NSW, Australia
Registered: Apr 2001

 - posted 08-23-2004 02:03 PM      Profile for Bill Langfield   Author's Homepage   Email Bill Langfield   Send New Private Message       Edit/Delete Post 
Yes 30 mins before show time at full power for a few minutes then to standby(about 55amps)current

Do you not get my point of the dangers of striking up at 10 seconds before screen time?

When do you strike up?
That is point of my whole question/post!

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Jeremy Fuentes
Mmmm, Dr. Pepper!

Posts: 1168
From: Corpus Christi, TX United States
Registered: Jan 2004

 - posted 08-23-2004 02:04 PM      Profile for Jeremy Fuentes   Email Jeremy Fuentes   Send New Private Message       Edit/Delete Post 
quote: Bill Langfield
Do you not get my point of the dangers of striking up at 10 seconds before screen time?
I guess not.

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John Pytlak
Film God

Posts: 9987
From: Rochester, NY 14650-1922
Registered: Jan 2000

 - posted 08-23-2004 02:09 PM      Profile for John Pytlak   Author's Homepage   Email John Pytlak   Send New Private Message       Edit/Delete Post 
First, I assume your system is designed and installed properly(e.g., shielding, separate circuits and UPS for sound processors), to minimize any audible effect of the xenon ignition pulse in the sound. If not, it should be corrected.

I don't really think it is necessary to run the lamp all day if there is a long time between shows. General "rule of thumb" is that each lamp ignition decreases lamp life by about one hour, so if the time between shows/reels is less than an hour, the lamp should be left on, with the dowser closed (assuming you have a dowser that can take the heat load without warping or being damaged).

I agree with you that it is a good idea to strike the lamp more than just a few seconds before the film needs to be projected. At least a few minutes would allow better stabilization of the arc, and a bit of "breathing time" to remedy things if the lamp does not ignite.

More than that would even allow time for changing a lamp, but is probably an unnecessary waste of electricity.

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Bill Langfield
Master Film Handler

Posts: 280
From: Prospect, NSW, Australia
Registered: Apr 2001

 - posted 08-23-2004 02:10 PM      Profile for Bill Langfield   Author's Homepage   Email Bill Langfield   Send New Private Message       Edit/Delete Post 
Can you please EXPLAIN your POINT or what you don't understand?

That said, I just remembered another location with Vic5 'console' built in lamphouses that have no standby, OVERHEAT between shows, so the automation turns the lamp off after every show, and strikes it up, 10 seconds before the next show.

So I have just killed my own agument very quickly. Damn it.
And the kicker is, Im told the on/off lamps are lasting longer.

Oh no JOHN, now I'm in trouble.(Did'nt expect you to chime in) You missed most of my point too.
The automation just tries igntion ONCE, if the lamp is long in tooth it might not light.
This is all about striking-up 10 seconds before the FIRST show of the day, nothing to do with leaving them on all day or if there was an hour between sessions. Granted 30 minutes might be too much.
How about I meet you half way at 10 or 15 minutes?

But when you have projection room the length of a football field, I'd like to be comfortable that cinema 16 is fired up and ready to go, while I'm getting cinema 1 ready. I dont want hear over the 2-way that cinema 16 has not fired the Xenon and have run down there. (we had scooters, but they got banned)

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Stephen Furley
Film God

Posts: 3057
From: Coulsdon, Croydon, England
Registered: May 2002

 - posted 08-23-2004 03:05 PM      Profile for Stephen Furley   Email Stephen Furley   Send New Private Message       Edit/Delete Post 
I recently did some projection at a place with a pair of Kinotons. The lamps strike on the motor start, and there is no way to strike them earlier. This place is running changeovers, and the eight seconds the lamp has before the actual changeover is not long enough. The picture is noticably dimmer, and the colour is different, after a changeover. It seems to take about 30 seconds to one minute to reach maximum light output. These are small lamps, I don't know if large ones would take longer.

I think anywhere between two and five minutes is a reasonable time to strike the lamp. I can't see any point in doing it earlier. It's unlikely that you wouldn't be able to get a lamp going in that time, another than a lamp exploding, and in the unlikely event that happens, the show will be late starting. Striking the lamp 30 minutes early won't help you if something goes wrong after 29 minutes.

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Bill Gabel
Film God

Posts: 3873
From: Technicolor / Postworks NY, USA
Registered: Jan 2002

 - posted 08-23-2004 04:47 PM      Profile for Bill Gabel   Email Bill Gabel   Send New Private Message       Edit/Delete Post 
When we do premieres or double-system previews we always strike the lamp 15-20 minutes before the show. That's always been the rule of thumb from all the studio screens that I've worked on the lot or on the road at a theatre. I strike both of my lamps 15 minutes before the show. Striking them a few seconds or minutes would not work for me. I handle media and post-production screens all day.

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Steve Kraus
Film God

Posts: 4067
From: Chicago, IL, USA
Registered: May 2000

 - posted 08-23-2004 05:51 PM      Profile for Steve Kraus     Send New Private Message       Edit/Delete Post 
I light'em up about a half hour before the first show and leave them on if the interval will be under about 45 minutes or so. Often they burn all day. But this is a screeening room (two projector changeover). Typically with a platter and automation the lamps strike with motor start. They can stabilize during the policy, etc. [Roll Eyes] Really though, with good lamps and good bulbs for normal commercial purposes this system seems to work fine in most cases, with decent presentation and decent bulb life.

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David Favel
Jedi Master Film Handler

Posts: 764
From: Ashburton, New Zealand
Registered: Feb 2002

 - posted 08-23-2004 06:24 PM      Profile for David Favel   Email David Favel   Send New Private Message       Edit/Delete Post 
We configured our automations not to strike.
We turn on 20 - 30 mins before the first show of the day. Just so if there is a problem, it can be fixed. Generally they are on 12 hours a day

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Josh Jones

Posts: 1207
From: Plano, TX
Registered: Apr 2000

 - posted 08-23-2004 06:37 PM      Profile for Josh Jones   Author's Homepage   Email Josh Jones   Send New Private Message       Edit/Delete Post 
you will find that most theaters (at least in the US) strike the lamp at motor start. Although I agree with giving the lamp a chance to stabilize, until lamps and consoles start coming with electric dowser closers, this will likely continue.

Also, isnt this a carry-over from the old days when you would let the arc settle for about two minutes to burn a crater into the positive carbon before the changeover?


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Mark Gulbrandsen
Resident Trollmaster

Posts: 16227
From: Bountiful, Utah
Registered: Jun 99

 - posted 08-23-2004 07:34 PM      Profile for Mark Gulbrandsen   Email Mark Gulbrandsen   Send New Private Message       Edit/Delete Post 
If I was building a multiplex for myself the lamps would all be struck a half hour before the show and all of them would remain on all day. I would also have pneumatic dampers on all the lamphouses that would open with the motor start closure and then the C/O would do its thing after the normal time out. We do have a few capable customers that actually do follow this routine.

Better for the equipment, better for the lamps in the long haul.

Mark @ CLACO

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Stephen Jones
Master Film Handler

Posts: 314
From: Geelong Victoria Australia
Registered: Jun 99

 - posted 08-23-2004 08:06 PM      Profile for Stephen Jones   Email Stephen Jones   Send New Private Message       Edit/Delete Post 
G'day Bill,

I strike the lamps 30min before the first session in that particular cinema and they stay on allday.It isnt a problem with Kinoton consols also same with Cinemecanicca consols.As you said you can change a lamp if you have to with out delaying a session and gives the lamp time to settle down.Had igniter board fail and found out by striking the lamp 30 min before the session, gave me time to get it running without delaying the session by to much.


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Brad Miller

Posts: 17688
From: Plano, TX (36.2 miles NW of Rockwall)
Registered: May 99

 - posted 08-23-2004 08:42 PM      Profile for Brad Miller   Author's Homepage   Email Brad Miller       Edit/Delete Post 
Again this is where the mighty CA21 comes in handy for platter multiplexes, as it can be configured to do anything you want it to do, even years after it was installed.

Personally, I have removed all of the electric dousers since about 2001. They are a pain (especially the Christie ones) and are just not needed in a platter booth. Instead I have a stretch of opaque black film at the end of each threading leader. The projectionist threads on the frameline leader, then when the show is started the motor runs until the start cue hits, where the xenon turns on (blasting onto the opaque film, so it looks to the audience like the douser is closed), then after a pre-programmed delay (currently 30 seconds) the non-sync fades out and the first green band hits the screen as the sound changes over. No dousers to jam, no arc stabilization issues, no problems...ever. [thumbsup]

Bill, I think you will find that proper cooling will add more life to the xenon than any other factor. The sides and front of my lamphouses with proper cooling are just barely warmer than room temperature.

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Steve Guttag
We forgot the crackers Gromit!!!

Posts: 12211
From: Annapolis, MD
Registered: Dec 1999

 - posted 08-23-2004 08:53 PM      Profile for Steve Guttag   Email Steve Guttag   Send New Private Message       Edit/Delete Post 
Hmmm....never had the changeover douser issue... [thumbsup]

As to Kinoton lamphouses...all of the ones I install have the ability to have the lamps strike manually. The three ways I install them (customer desire): 1)completely manual strike with no projector control (this is for our typical for manual changeover booth). 2) extra switch with an "auto" and On position. 3) Extra switch with Auto/Off/On positions. We also give the option of the blowers to run all of the time or just when the lamp is lit + cool down.

I've done all of the above with either a single toggle or two toggles.


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