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Author Topic: Stuck pixel during DLP presentation
Aaron Haney
Master Film Handler

Posts: 265
From: Cupertino, CA, USA
Registered: Jan 2001


 - posted 07-16-2008 08:35 PM      Profile for Aaron Haney   Email Aaron Haney   Send New Private Message       Edit/Delete Post 
This past Sunday I went to the first DLP presentation I've been to in a while, and there was a stuck pixel visible throughout the entire show. It took the form of a bright blue dot near the center of the screen. Very annoying. It was only present during the trailers and feature, not during the pre-show (which was clearly running from a separate system).

Is there anything the theater can do about this, short of replacing the projector?

Theater management was informed, but the response was not encouraging. We got a couple of free passes out of it, and it was made clear we were lucky to get that. I have serious doubts anything will be done.

In case anyone is wondering, it was auditorium number 6 at the Century at Tanforan in San Bruno, CA.

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99


 - posted 07-16-2008 08:51 PM      Profile for Mark Gulbrandsen   Email Mark Gulbrandsen   Send New Private Message       Edit/Delete Post 
Possibly, but they will have to call in a tech to see. It is sometimes possible to free up a stuck pixel(s) by exerising the DMD's. We recetly conducted a Christie DLP training class at CLACO and the instructor mentioned something about doing this.... I believe he said there is a test pattern in the latest or last version of the T.I. Software tht can be used for excercising the pixels... they are pulse width modulated! If its the DMD that does turn out to be defective then you replace the light engine assembly not the entire projector. It may also still be under warranty.

Mark

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Joe Redifer
You need a beating today

Posts: 12859
From: Denver, Colorado
Registered: May 99


 - posted 07-16-2008 10:22 PM      Profile for Joe Redifer   Author's Homepage   Email Joe Redifer   Send New Private Message       Edit/Delete Post 
quote: Aaron Haney
We got a couple of free passes out of it, and it was made clear we were lucky to get that.
Sounds like the customer service sucks at the Century at Tanforan in San Bruno, CA. What a horrible theater. They do not deserve to be in business if they are telling you that you are "lucky" to get passes even when their equipment is broken. Do not go to that theater ever again. If you use your free passes, do NOT purchase concessions. Write their corporate headquarters and see if anyone who works there actually cares (don't get your hopes up).

The manufacturers of DLP equipment had better come up with a solution fast. How pathetic is a stuck pixel?

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99


 - posted 07-16-2008 10:32 PM      Profile for Mark Gulbrandsen   Email Mark Gulbrandsen   Send New Private Message       Edit/Delete Post 
quote: Joe Redifer
The manufacturers of DLP equipment had better come up with a solution fast. How pathetic is a stuck pixel?

Ha! Its about as pathetic as a scratched filum print... for which filum manufacturers never came up with a solution for either.

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Joe Redifer
You need a beating today

Posts: 12859
From: Denver, Colorado
Registered: May 99


 - posted 07-16-2008 10:52 PM      Profile for Joe Redifer   Author's Homepage   Email Joe Redifer   Send New Private Message       Edit/Delete Post 
A sloppy projectionist doesn't cause a stuck pixel. Also, once that scratched print is replaced, scratch is gone. Stuck pixel shows on every show FOREVER until fixed. What a horrible analogy. You should have compared it to a chipped lens or a torn screen instead. Ooops, that can happen on DLP as well!

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Geoff Jones
Jedi Master Film Handler

Posts: 579
From: Broomfield, CO, USA
Registered: Feb 2006


 - posted 07-17-2008 12:18 AM      Profile for Geoff Jones   Author's Homepage   Email Geoff Jones   Send New Private Message       Edit/Delete Post 
Heh - I had that exact same problem with my LCD projector (Sanyo PLV-60HT) at home. The first unit I got had a blue pixel stuck "on."

I lived with it for a few days (hoping maybe it would get unstuck?), until I had friends over to watch The Terminator. Friend's wife: "Oh look, the blue dot is on Arnold's pee-pee now." The projector went back in the mail immediately and I got the vendor to inspect the next unit before they shipped it.

Oh, and I saw a brand new 35mm print of The Terminator this year at a packed house at the Castro Theatre and it ROCKED. Long live film!

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Aaron Haney
Master Film Handler

Posts: 265
From: Cupertino, CA, USA
Registered: Jan 2001


 - posted 07-17-2008 12:46 AM      Profile for Aaron Haney   Email Aaron Haney   Send New Private Message       Edit/Delete Post 
They did not actually use the word "lucky", but there was a clear resistance to doing anything and general lack of concern. I certainly don't plan on returning to that location.

Also, I think it's unfair to compare this problem to print damage such as scratches or dirt. The blue dot was visible on every single frame of the movie, yet it's beyond rare that I've seen scratches or dirt that covered every single frame of a print, or even close to it. I can easily ignore dirt and scratches because I know they are almost always gone quickly. A bright blue speck in the middle of the screen that stays for the entire duration of the feature is quite different. The person who attended the movie with me agreed -- they are normally not bothered by minor problems, but found this very annoying.

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Andy Frodsham
Expert Film Handler

Posts: 238
From: Stoke on Trent, Staffs, UK
Registered: Nov 2006


 - posted 07-17-2008 06:34 AM      Profile for Andy Frodsham   Email Andy Frodsham   Send New Private Message       Edit/Delete Post 
Wow, for some, seemingly, naive reason, I didn't think that commercial digital projectors would be prone to this 'stuck pixel' problem! Don't ask me why I thought this way - possibly the cost of the units and the fact that this technology is being hailed as the best thing since sliced bread!

This must inevitably pose massive potential problems for the system?

I'm not gloating - honestly!

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Stephen Furley
Film God

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From: Coulsdon, Croydon, England
Registered: May 2002


 - posted 07-17-2008 07:21 AM      Profile for Stephen Furley   Email Stephen Furley   Send New Private Message       Edit/Delete Post 
quote: Mark Gulbrandsen
If its the DMD that does turn out to be defective then you replace the light engine assembly not the entire projector. It may also still be under warranty.

How much does that cost, assuming that it's not under warrenty? How long is the warrenty? How long is the typical life of these devices? How much would you expect to pay for a maintenance contract that would include replacement of these if they do fail?

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99


 - posted 07-17-2008 09:17 AM      Profile for Mark Gulbrandsen   Email Mark Gulbrandsen   Send New Private Message       Edit/Delete Post 
quote: Stephen Furley
How much does that cost, assuming that it's not under warrenty?
ALOT!

quote: Stephen Furley
How long is the warrenty?
Thats up to the customer. We've sold extended warranties on all the Christie's we've sold... So that makes the manufacturers warranty 5 years. I don't know if the other DLP manufacturers offer extended warranties at all but Christie sells extended warranties in 2 year increments at the time of purchase.

quote: Stephen Furley
How much would you expect to pay for a maintenance contract that would include replacement of these if they do fail?

Maintainance contracts rarely include parts costs however you can get insurance for this sort of thing.

To me a stuck pixel would also be very annoying but so is the common printer bounce we see in almost every print struck today.

Mark

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Jim Cassedy
Phenomenal Film Handler

Posts: 1661
From: San Francisco, CA
Registered: Dec 2006


 - posted 07-17-2008 10:44 AM      Profile for Jim Cassedy   Email Jim Cassedy   Send New Private Message       Edit/Delete Post 
I haven't been to the Century Tanforan 6 yet, but have driven by it several times on my way to the airport.

That's interesting about the stuck pixel.
The Century 6 Tanforan has been open less than 6 months and took out full-page color centerfold advertisements in several of the local San Francisco Bay area newspapers the weekend they opened proclaiming that all their auditoriums used "superior" digital projection.

A bit of history for those outside of the SF Bay area-
Century 6 is located in a shopping center that sits on the site of the former Tanforan race track.(horse racing)

During WWII, the Tanforan track was also used as a 'holding and processing area' for Japanese-Americans before they were shipped off to internmant camps.

I understand that it was a different time, place and set of circumstances, but I've never visitied that mall or had any desire to see the new "superior" Century 6 just because the whole place made me uncomfortable.

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Frank Angel
Film God

Posts: 5305
From: Brooklyn NY USA
Registered: Dec 1999


 - posted 07-17-2008 01:35 PM      Profile for Frank Angel   Author's Homepage   Email Frank Angel   Send New Private Message       Edit/Delete Post 
Most scratches and dirt are intermittent. Stuck pixels are steady-state and MUCH more annoying. Scratches and dirt come from poor handling of the film, not from the projector. You can change a damaged print; it's a lot more costly to replace that DLP nano mirror module. And this is only a few years out. At least with a 35mm film projector, you don't expect to find its weaknesses showing up this early on.

Look, there is NO technology that is perfect. There are going to be weaknesses. With digital, the maintenance costs to keep ahead of them showing up is much more costly than with a film based system. Stuck or dead pixels are inherent in the video display technology, so someplace along the line those specks of light or black are going to start to populate digital projector displays, the question is how soon and how costly will it be to repair them.

Second question is, those same theatre operators who wouldn't foot the cost to buy a supply of Film Guard and a Kelmar cleaner to prevent dirt and scratches or who let bulbs burn to the point were the picture is barely visible, they're THE SAME GUYS running the digital booths. How reluctant will these owners be to replace a very expensive malfunctoning nano-mirror module? Only time will tell, but I wouldn't put any bets on theatre owners stepping up to the plate when digital equipment starts to show its age. The big problem is that it may very well start showing its age long before a 35mm projector shows it's flaws.

The digevangelists were always comparing how images looked when the DLPs were newly tweaked and practically out of the box against old 35mm equipment that had been running in theatres for decades. It wasn't a fair comparison. Sure, you can plop a new $100,000 digital projector system in a theatre that's been run poorly and it will fix a multitude of sins -- for the moment, but it is still in a theatre that is RUN POORLY. The equipment won't change that. Sooner or later the neglect that made 35mm look bad there will impact the digital there as well. And since digital will cost ALLOT more to repair, it is foolish to think these operators will give any more of a rats ass about presentation than they did with their 35mm systems -- extended warantees not withstanding.

BTW, extended warantees don't make it any less expensive to repair or replace these modules -- it only shifts the cost, and whoever is absorbing that cost is going to pass it back onto the end user one way or another. The cost of having a technician come in to replace failing DMDs is much more than a tech coming in to repair an mechanical intermittent.

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99


 - posted 07-17-2008 05:38 PM      Profile for Mark Gulbrandsen   Email Mark Gulbrandsen   Send New Private Message       Edit/Delete Post 
I'm still sort of chuckling at how everyone assumes this is a stuck pixel while there are at least a few other things that can cause a blemish like this in the image. Integrator rod, Fold Mirror, lens, etc. None of these are all that expensive to repair. And yes, when a print is scratched on a platter system its usually all the way through and the booth jockey had no idea that it was being scratched. Perhaps this says something in favor of Guttag's reels. Indeed, no system is perfect nor should it be as we'd all be out of buisness.

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Aaron Haney
Master Film Handler

Posts: 265
From: Cupertino, CA, USA
Registered: Jan 2001


 - posted 07-19-2008 01:44 AM      Profile for Aaron Haney   Email Aaron Haney   Send New Private Message       Edit/Delete Post 
The lens could have caused it? Huh?

It was a small dot in sharp focus, just the right size to be a pixel, and it remained full brightness even when the entire rest of the image went black. It was also strongly blue, one of the component colors of the 3-chip system.

The fact that it always remained at full brightness is by itself enough to rule out most other possibilities I would think, especially anything in the light path prior to the DLP chips (otherwise it would have gone dark along with the rest of the image whenever there was a fade to black).

And for the record, the last time I saw a scratch on a 35mm print, it lasted less than a minute.

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Stephen Furley
Film God

Posts: 3059
From: Coulsdon, Croydon, England
Registered: May 2002


 - posted 07-19-2008 03:38 AM      Profile for Stephen Furley   Email Stephen Furley   Send New Private Message       Edit/Delete Post 
Mark,

In rough terms how much would you say it costs, per year, to run a typical digital projector?

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