Film-Tech Forum ARCHIVE: Vertical And Horizontal Xenon Bulb Working Position

This is topic Vertical And Horizontal Xenon Bulb Working Position in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Marin Zorica (Member # 1716) on 05-05-2004, 10:39 AM:

I saw that lot of "older" projectors had a lamp house with vertical xenon bulb, and today, modern kind of projectors had a horizontal position xenon bulb in lamp house, mostly with aspheric dichroic mirrors as far i know, i saw also that in some horizontal lamp hoses bulb plus " " is in mirors, and on other is oposite off mirror.

Why is this like that, and what are differences between horizontal and vertical lamp working position???

Also for XBO1600w/ofr, and XBO2500/ofr what is required power of rectifier, and what is ignition voltage of this lamp??

Thanks, Marin

Posted by Jeremy Fuentes (Member # 2135) on 05-05-2004, 10:42 AM:

I could be wrong, but I believe the bulb lasts longer when it is in vertical position. Or at least doesnt have to be rotated as much.

Posted by Aaron Sisemore (Member # 145) on 05-05-2004, 11:26 AM:

The only vertical lamphouse manufatured today is made by Lighting Images Technology .

The sole advantage to vertical lamps is that in practice the bulbs can last a VERY long time, when properly cooled, as there is no sagging of the electrodes or uneven blackening of the lamp (both are reasons that horizontal lamps have to be rotated at regular intervals).

The worst part of a modern vertical lamphouse is the requirement for the diagonal 'folding' mirror that turns the light beam 90 degrees- it is notorious for robbing valuable light. Vertical/folding mirror lamphouses are also more difficult to align than their horizontal counterparts.

-Aaron

Posted by Thomas Procyk (Member # 1170) on 05-05-2004, 11:55 AM:

Hmmm. I had a tech tell me a long time ago that we should NEVER rotate our xenon bulbs, because it "cuts the life in half" when you do so. [Confused]

Theater I was at at the time had Big Sky lamphouses.

I don't mess with the things. Not paid enough. [Razz]

=TMP=

Posted by John Walsh (Member # 168) on 05-05-2004, 11:58 AM:

There's also les flickering when mounted horizontal.

Posted by Bruk Mogos (Member # 2043) on 05-05-2004, 08:48 PM:

horizontal mounted lamps last longer and they have great output of light and they don't have to be rotated,as to vertical mounted lamps you loose some light since it's reflecting through the mirror, and they consume more electricity to compensate for the loose of light. ex. (7000W vertical = 4500W Horizontal)

and required power of rectifier for XBO 2500W- I think is 25 Volts 75 AMP,I don't know about 1600w.

Posted by Gordon McLeod (Member # 33) on 05-05-2004, 09:44 PM:

"horizontal mounted lamps last longer and they have great output of light and they don't have to be rotated,as to vertical mounted lamps you loose some light since it's reflecting through the mirror, and they consume more electricity to compensate for the loose of light. ex. (7000W vertical = 4500W Horizontal)
and required power of rectifier for XBO 2500W- I think is 25 Volts 75 AMP,I don't know about 1600w. "I would check some facts first
Horsizontal lamps do not last as long the XBO2500OFR holds the record on that department in vertical XenosolIII's aslo vertical lamps don't get rotate horizontals in many cases must be rotated
A vertical in the convential design is less efficient but will produce a flatter light field if fitted with an auxilory reflector also
John said"There's also les flickering when mounted horizontal. "Horizontal lamps will flicker worse as they are by nature unstable and require magnetic stabalization

The reason some lamps are mounted backwards is to keep the anode higher than the cathode in steep inclined locations (spotlight for example)

a 2500 watt lamp is designed for 80-100amp operation

Posted by John Walsh (Member # 168) on 05-06-2004, 08:24 AM:

Opps! Gordon is right; I meant to write 'vertical.'

Posted by David Rigby (Member # 1301) on 05-06-2004, 10:56 AM:

What physical attribute of a horizontal bulb prevents it working in a vertical position - is it just that it's too short? If so can metal extenders be used to correct the length? (since I need to do this anyway to use 500 or 1000W lamps in my 2K lamphouse [Smile]

)

Posted by Gordon McLeod (Member # 33) on 05-06-2004, 11:03 AM:

Horizontal lamps burn quiet happily when mounted vertically the reverse isn't true and they require very high magnetic stabalization if done so

Posted by David M. Dorn (Member # 2298) on 05-07-2004, 09:10 PM:

While we are on the topic of verticle lamps, I noted that the Cinemeccanica CX 1600 Lamphouse had a verticle lamp but did not use a 45 deg. mirror. The illuminaton was foucused by a shallow reflector.

Did any other manufactures take this approach? And if not, why not, given the improvement in lamp life using the verticle postion.

Posted by Richard Fowler (Member # 893) on 05-07-2004, 09:18 PM:

When the CX1600 was designed there where other manufacturers also using the "Butterfly" type of shallow reflector in the 1960 -70's period...very inefficient but long bulb life.

Posted by John Pytlak (Member # 331) on 05-07-2004, 09:37 PM:

Such as the Zeiss-Ikon Xenosol lamphouses, which also had a "honeycomb" condenser lens assembly. We had a pair in one of our screening rooms in the early 70's.

Posted by David M. Dorn (Member # 2298) on 05-07-2004, 10:10 PM:

John,

Am I correct to assume the Xenosol's condenser lens was between the lamp and aperture, like that on a condenser equipped photographic enlarger? I also assume the honeycomb concentrated the light much like a tail light reflector.

Posted by John Pytlak (Member # 331) on 05-07-2004, 10:22 PM:

It's been a long time, but I recall the vertical lamp had about a 3-inch diameter spherical "auxillary reflector" reflecting light back toward the main reflector, and two honeycomb condenser lenses mounted together near the snout of the lamphouse.

There's a photo in the "Pictures" section:

http://www.film-tech.com/pics/royal/royal.html

Or in some that Gordon took:

http://www.cinephoto.co.uk/gordon_mcloed_2.htm

Here's some history of ZeissIcon:

http://www.phototechnik-online.de/ZeissIcon/ZeissIconAG.htm

Posted by Gordon McLeod (Member # 33) on 05-08-2004, 09:18 AM:

The honeycomb lens for the xenosol was required for lamps of 900watts or less. 1600 and 2500 and 6000 jut ad a heat filter in the nose cone. For 16mm use there was a condensor lens

Posted by David M. Dorn (Member # 2298) on 05-08-2004, 10:55 AM:

The Lincoln Center equipment list for Avery Fisher Hall show they have a Zeiss Ikow lamphouse in the booth. Must be a special modkel. [Roll Eyes]

The is the list:

"Motion Picture Equipment:

Screens: Hurley matte white perforated screen
18'2"h x 30'w
Aspect ratios: 33, 66, 85, Scope, Silent and 16mm
Wall to wall adjustable black velour maskings available

Projectors:
Two (2) Simplex X-L 35mm Projectors

Light Source: Ashcraft "Core Light" High Intensity Projection Arc lamps
Lens Ratios: 1:33, 1:66, 1:85, Scope, when screen is hung from Stage Pipe #2 One (1) Eastman Arc Model 40

Light Source: Zeiss Ikow Xenosol II, 1600w

Motion Picture Sound:
Dolby Cinema Sound Processor CP-55 capable of producing Dolby Stereo (no surrounds)"

Anyone actually seen this booth?

Posted by Gordon McLeod (Member # 33) on 05-08-2004, 11:46 AM:

quote"The Lincoln Center equipment list for Avery Fisher Hall show they have a Zeiss Ikow lamphouse in the booth. Must be a special modkel. "

There is nothing special with the xenosol II lamphouse to use i for 16mm just the condensor in the nose cone

Posted by David M. Dorn (Member # 2298) on 05-08-2004, 12:12 PM:

The face was for the Avery Fisher spelling of IKON as IKOW. I put it in bold when I copied the exact listing from the Lincoln Center web site but it did no reproduce in the post. [Confused]

I assume that Xenosol was for the Koadak Eastman Arc Model 40 projector (16mm???) even though the format of the listing had it separated from the Kodak projector.

Posted by System Notices (Member # 2357) on 01-03-2006, 08:53 PM:

It has been 605 days since the last post.

Posted by Mike Croaro (Member # 3123) on 01-03-2006, 08:53 PM:

Hi Folks:

The Belmont Theatre (Belmont, CA) had lamphouses like John P. describes. Christie BSG with dual mirrors. Large Butterfly mirror in the back of the unit. Smaller cone shaped "forward mirror" in FRONT on the lamp. Forward mirror throws "lost" light back onto the back main mirror and then shoots the light out thru the nose of the unit.

The forward mirror was supposed to improve light output. These had been long removed because the projectionist at the time did not believe there was a benefit to them in terms of incresing light. Rather he believed that they overheated the envelope of the lamp thus decrease the life of the lamp.

Does the forward mirror improve light out output or was it a failed attempt in design?

Mike

Posted by Robert Throop (Member # 61) on 01-04-2006, 06:29 AM:

quote: David M. Dorn
Light Source: Ashcraft "Core Light" High Intensity Projection Arc lamps

These lamps are now in the Capitol theatre, Rome, NY where we frequently screen silent and other classic films. We still use the original Moller pipe organ.
I think the lamps now in Avery Fisher Hall are Xetron.
Bob

Posted by Marin Zorica (Member # 1716) on 01-04-2006, 03:16 PM:

Does the forward mirror improve light out output or was it a failed attempt in design?

Off course is improved if is positioned and aligned well!

Posted by Dave Macaulay (Member # 813) on 01-04-2006, 03:32 PM:

The forward reflex mirror does improve the light if it's aligned properly. only the light from the lamp that shines on the mirror gets reflected towards the aperture (OK, some light shines directly on the aperture with no reflex mirror). The reflex mirror takes the wasted light shining from the "front" of the lamp and reflects it back through the lamp towards the main reflector. Quite a bit is lost but certainly there's a gain in screen brightness.
The envelope and electrodes will run somewhat hotter but that shouldn't be a problem.
Running without the reflex mirror shouldn't be a problem either if you can get enough light on the screen. They rarely survive a lamp explosion and are pretty easy to break while relamping... it isn't unusual to find them missing.

Posted by Alex Cross (Member # 3520) on 01-05-2006, 06:20 AM:

I think some of you are missing the point (sorry, no put down or insult intended). The lamp in a vertical lamp house last longer due to the positioning of the flame itself inside the quartz bulb. If you turn a candle on inside, the flame will automatically rise. It's the same principal with Xenon in a vertical/horizontal lamp house. Because the Xenon in a horizontal lamp house is effectively on its side, magnetic forces are needed to pull the flame down into an ideal operating position. This is why until recently; it was common practice to rotate the lamp half way through its life, to even out wear on the tungsten tips, and to reduce the blackening on one side of the lamp, (we use Osram by the way). With the advances in lamp manufacture, it is no longer essential to rotate the lamp. I have worked with both types of lamp houses, and I have to say, I prefer the vertical, if only for ease of lamp replacement. Hope this helps [Wink]

(I am new to this, so forgive me if I have annoyed anyone).

Alex.