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» Film-Tech Forum   » Operations   » Digital Cinema Forum   » Barco DP2k-10s not using max. light output (Page 1)

 
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Author Topic: Barco DP2k-10s not using max. light output
Marlon Martins
Film Handler

Posts: 73
From: Torres, RS, Brazil
Registered: Apr 2015


 - posted 11-23-2015 01:04 AM      Profile for Marlon Martins   Email Marlon Martins   Send New Private Message       Edit/Delete Post 
Hi, i'm burning neurons on this one.

A while ago, the projector on the cinema i was helping to set up had a few weird light problems. after a LPS failure, the light output went basically to 10% of "nominal" output let's say. but the thing is, outside the lamp housing is clear that the lamp is in good shape and power, by the light on the outside of the housing, but on the projection itself, was barely visible. Changing the lamp fixed it, but only partially.

First, the light output around the housing was equal, but the light output of the projection was still not great. with a luxmeter, was measured 50 lux at bottom of the screen. its not a proper fl measure, but allow to keep a record of how the lamp is. setting the output to manual (at 255) or CLO, the light was still at 50 lux. (and in the lamp configuration, its shows at maximum power, 2200W, 85A)

then, a technician came to see it and it changed "something" and the light output went to 97 lux. but the lamp is still a t 2200W, it put on CLO mode (tried and the light output is still 50 lux) but i would assume using it on manual at maximum would get the max output, but no luck. tried everything i could imagine that affects the output, and again, no luck.

so, the main question: it there any "trick" on this projector for max light output? cause it does not appear to be on the light itself, but on the projector. lens is clean, lamp is properly aligned, and yet, 50 lux on screen (making worst on 3D due to polarize and glasses losses)

thanks in advance [Wink]

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Marco Giustini
Film God

Posts: 2545
From: Reading, UK
Registered: Nov 2007


 - posted 11-23-2015 01:21 AM      Profile for Marco Giustini   Email Marco Giustini   Send New Private Message       Edit/Delete Post 
What is the size of your screen?

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Marlon Martins
Film Handler

Posts: 73
From: Torres, RS, Brazil
Registered: Apr 2015


 - posted 11-23-2015 02:04 AM      Profile for Marlon Martins   Email Marlon Martins   Send New Private Message       Edit/Delete Post 
Width is 8.6 meters if i recall

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Ian Freer
Expert Film Handler

Posts: 133
From: Wellington, New Zealand
Registered: Oct 2003


 - posted 11-23-2015 09:54 PM      Profile for Ian Freer   Email Ian Freer   Send New Private Message       Edit/Delete Post 
The following may not be pertinent as the results are a very significant drop in light, but thought I'd suggest it just in case as I am not familiar with the 8/10x Barco's and how the lamps mount into the lamp house...

A trap I've seen people fall into with the C series was the lamp was not sitting fully back in the slots in the Cathode mount.

 -

I have someone slide the lamp all the way in, but not quite hold the lamp tight enough so when they tightened the allen screw they pushed the lamp forward just enough for the pins to move out of the slots then tighten against the upper edges of the slots accidentally.
This pushed the lamp arc far enough forward that while there was some light making it to the screen, there was a very significant lack of light output...

Just a thought...

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Monte L Fullmer
Film God

Posts: 8318
From: Nampa, Idaho, USA
Registered: Nov 2004


 - posted 11-24-2015 03:02 AM      Profile for Monte L Fullmer   Email Monte L Fullmer   Send New Private Message       Edit/Delete Post 
I usually rotate the bulb in the castle nut until I feel it slide in farther and knowing that the pins are in the castle part of the rear nut, preventing full rotation.

I add the 5mm allen bolt and turn the bolt until its threaded in the cathode adapter but leave it loose.

I'll add the UV filter front end assembly with holding up the bulb to meet the anode seal end pin to the UV filter anode mount.

I hold the bulb back into the castle nut while I snug down the 5mm Allen bolt. Just don't tighten down too much, being that adapter is solid brass, for one of the mgrs here on a change out at on theatre, snapped the end off of an adapter by getting hefty with the allen tool.

If the Anode connector is at the bottom of the module, I have the anode cable also down at the 6:00 position since the cable is on the short side. For the B units, the connector is at the 3:00 position and I do the cable accordingly.

Another issue with the cathode adapter is the lock down allen set screw: That has to be snugged down real good, but still not too tight. If that doesn't get locked down, a possible overheating and assembly burn up can be the results (also with poor light emissions), since that lockdown setscrew makes direct contact with the cathode seal collar.

It's presumed that the threading of the adapter to the end of the bulb is suffice, but that setscrew is the key for direct contact.

-Monte

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Marco Giustini
Film God

Posts: 2545
From: Reading, UK
Registered: Nov 2007


 - posted 11-24-2015 06:00 AM      Profile for Marco Giustini   Email Marco Giustini   Send New Private Message       Edit/Delete Post 
has this screen ever reached proper brightness readings in the past?

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Marin Zorica
Jedi Master Film Handler

Posts: 654
From: Biograd na Moru, Croatia
Registered: May 2003


 - posted 11-24-2015 09:14 AM      Profile for Marin Zorica   Email Marin Zorica   Send New Private Message       Edit/Delete Post 
Something is not clear here, you said that even you change light output setting in normal mode, say from 200 to 255 you have same light on screen? What did you use for measuring light? Some photografp luxmeter, maybe is bad!? Also, when you move slider for current adjustment on communicator, do you see screen brightness changing?

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Marlon Martins
Film Handler

Posts: 73
From: Torres, RS, Brazil
Registered: Apr 2015


 - posted 11-25-2015 03:01 AM      Profile for Marlon Martins   Email Marlon Martins   Send New Private Message       Edit/Delete Post 
thanks for the tips. will look into the lamp to see if anything is not properly mounted.

@Marco:
yes, with a 1000 hours ushio was measured 97 lux at the screen. now it has a 400 hours lamp, new power supply, but 50 lux on screen. on settings the lamp seems fine, running at max power

@Marin:
the light output slider works properly, reducing or increasing i can see the light output changing, the luxmeter is doing a proper reading, and the power measurements from the lamp are changing accordingly. but at the max settings, (255) the light output to the screen is still about half of what was before.

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Carsten Kurz
Film God

Posts: 3779
From: Cologne, NRW, Germany
Registered: Aug 2009


 - posted 11-25-2015 04:15 AM      Profile for Carsten Kurz   Email Carsten Kurz   Send New Private Message       Edit/Delete Post 
Even 97lx at the screen is far below what should be there. Did you compare this with other screens, using a full-white test DCP?

- Carsten

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Marin Zorica
Jedi Master Film Handler

Posts: 654
From: Biograd na Moru, Croatia
Registered: May 2003


 - posted 11-25-2015 04:53 AM      Profile for Marin Zorica   Email Marin Zorica   Send New Private Message       Edit/Delete Post 
Than probably lamp/reflector/lamphouse is not properly aligned

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Dave Macaulay
Film God

Posts: 2136
From: Toronto, Canada
Registered: Apr 2001


 - posted 11-25-2015 05:32 AM      Profile for Dave Macaulay   Email Dave Macaulay   Send New Private Message       Edit/Delete Post 
The "ball joint" thingy in the lamphouse cathode receiver can slide forward and destroy the abilty to focus the lamp, I've found a few like this. You can't peak the Z axis adjustment however.
I avoid using CLO on S projectors, the CLO reading varies with image brightness. It seems impossible, since the CLO sensor is before the prism... but it does. Some units do it more than others. I thought it had been corrected with a software fix because I found some where the difference is slight, but recently upgraded a few with no change - pretty severe change in CLO sensor reading between white and black patterns.
I think the 10s would be underpowered for an 8M 3D screen. The Barco calculator includes it only if optical loss and lamp life output decay are set very low: ie it should give adequate light with a new lamp, perfect port glass, and no colour correction (reads 0.314/0.351 on uncorrected white). Add much optical and lamp loss, and the 15C is the smallest projector recommended.

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Marlon Martins
Film Handler

Posts: 73
From: Torres, RS, Brazil
Registered: Apr 2015


 - posted 11-25-2015 11:19 AM      Profile for Marlon Martins   Email Marlon Martins   Send New Private Message       Edit/Delete Post 
i tried the lamp adjustment on the housing, all tree axis have a "peak" output when adjusting (like very low, low, mid, high, mid, low, very low..), so, does this means the lamp is properly set? or it would be peaking at the limit of the Z axis screw?

@Carsten
only one screen for now, in a few weeks another one will be installed, so i could compare both projectors output at same distance (the projector is the same, but in a bit smaller screen)

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Marin Zorica
Jedi Master Film Handler

Posts: 654
From: Biograd na Moru, Croatia
Registered: May 2003


 - posted 11-25-2015 01:17 PM      Profile for Marin Zorica   Email Marin Zorica   Send New Private Message       Edit/Delete Post 
The real thing is to check does lamp actually lights at proper current and voltage, because as you said that happend after LPS replacement, it could be that reading were wrong, even i doubt on that.

Next, if lamp and lamphouse is ok, that it could be light engine problem, in case somebody open it, it can be that cold mirror or integrator rod was moved and now missaligned....as you said LPS was changed, it could be that somebody touch cold mirror assembly??

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Marlon Martins
Film Handler

Posts: 73
From: Torres, RS, Brazil
Registered: Apr 2015


 - posted 11-25-2015 02:33 PM      Profile for Marlon Martins   Email Marlon Martins   Send New Private Message       Edit/Delete Post 
the inside of the lamp housing seems ok (i cleaned a wile ago, the mirror, uv filter, etc..

the thing is, the old lamp and PS had the same problem, and looks like only the configuration was changed when the light changed from 50 to 97 lux.

i dont know was was changed, but i will look into the lamp to make sure the problem is not there.

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Phil Ranucci
Expert Film Handler

Posts: 227
From: Carpinteria,CA, United States
Registered: May 2006


 - posted 11-25-2015 03:26 PM      Profile for Phil Ranucci   Email Phil Ranucci   Send New Private Message       Edit/Delete Post 
Check what fl level is set in the macro configuration file.
When setting the power level, what is the max fl the display shows? Compare that number to the number in the macro.
I'm betting on mirror misalignment.
The setscrew and adaptor have torque settings, 2.5 nM and the cable is 9 nM. ( B and C series)

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