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Topic: SRD - Penthouse or Basement - preference?

Kevin Wale
Expert Film Handler

Posts: 167
From: Guymon, OK USA
Registered: Aug 2003

posted 04-12-2005 04:51 PM

quote: Steve Guttag
What I wish DTS did offer was a better reader or a version that would allow it to go in place of a 35 mag head so the film would be stable and not suffer from weave and bounce.

Is there something about the DTS readers that causes weave and bounce? I've never heard that was a problem, or never thought of it, or something. I know if you don't get the film around both of those rollers you'll regret it. lol

Also, with that problem mentioned, do you think all DTS installations should include a film stabalizer perhaps underneath the reader?

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Steve Guttag
We forgot the crackers Gromit!!!

Posts: 12814
From: Annapolis, MD
Registered: Dec 1999

posted 04-12-2005 05:53 PM

I use CE basement readers almost exclusively...if you can't get them to track well...you aren't doing a very good job.

As to DTS...yes they do allow a bit of weave and if there is any bounce in the film, it will translate into poor tracking and some "wow" problems.

As to Cat. 702 and BACP readers...if the unit is powered 24 hours, it will kill the LED life. We have been known to put a switch in line on the LED though.

As far as LED replacement goes...CE is the easiest...they are socketed by fixed sockets (Kelmar's float). While BACP LEDs are changed as a unit...the CE is the cheapest since only the LED gets changed.

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99

posted 04-12-2005 05:56 PM

quote: Kevin Wale
Also, with that problem mentioned, do you think all DTS installations should include a film stabalizer perhaps underneath the reader?

The DTS reader is a woefully inadaquate device! How stable a DTS system behaves is purely a matter of what equipment it is working with. Yes, a stabilizer in the form of a semi-tight loop system would work wonders for it. When we adapted it to the DP-70 mag penthouse position we utilized some of the original penthouse tight loop copmponents to achieve this. These systems don't exhibit even the slightest tracking difficulties or ever even blip at all. The only real problem that exists is if the print's time code track is bad. Also the LED system in the reader is simply a joke of the largest degree. It's level drifts ALOT and costs the theatre owner about 300.00 to get a DTS R/A reader..... this much $$ to replace a 50 cent LED.

CE did improve their optics as did Kelmar but I still don't like the CE digital camera as its nhot as well protected or their ASR-40 pickup, the more expensive CE analogs are fine but the BACP has them beat there anyway.. I find the Kelmar LEDs just as easy to replace as the CE. Weather the socket floats or not is really irrelevant during LED replacement. I always take the foot loose fomr the sound reproducer to do a good clean out anyway.

Mark

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Sam D. Chavez
Film God

Posts: 2153
From: Martinez, CA USA
Registered: Aug 2003

posted 04-12-2005 08:28 PM

Monte,

One can always break the line on the LED wiring and tie it across a relay that pulls in when the projector motor is running if you feel the need.

On analog readers, you need to damp the LED inrush current or you will get a pop as the LED has no thermal lag like an exciter lamp. If you have the sound system set to optical you will definitely get a thump. A good way to damp the inrush is a 5000 uF Cap in series with a 10 Ohm or so resistor.

CE analog power supplies do have some contact points you can close or open to provide a soft start. Problem is, last time I looked they are wired backwards unless you have CE automation but they may have addressed this by now.

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Richard May
Phenomenal Film Handler

Posts: 1057
From: Floral Park, NY USA
Registered: Aug 2004

posted 04-12-2005 08:35 PM

Sam, they are still wired backwards.

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Frank Angel
Film God

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

posted 04-13-2005 01:01 AM

Hey, thanks guys. I think we are going to go with the BACP DSTR-20 penthouse for ease of installation and mostly because of economics over DA-20. They weren't kidding when they put the NON in non-profit with our operation. As for projectionists who get spooked by threading a penthouse, well, he'd be out on his butt in a Brooklyn minute. Anyway, mostly it will be me running.

And John, yes we do still run mag so the mag penthouses have to stay. I love the idea though of incorporating a DTS reader in the mag penthouse! I am sure if there were a demand for it, it could be nicely designed and it would be an elegant solution to all those add-ons.

Oh, and my bad for not saying it is a Simplex XL and SH-1001 (I think).

We hardly ever run 6000ft so lifting the heavy LP reels won't be much of a problem -- 2000ft is no problem. The reason I was a little wary of the height was because I always have this image in my head of a projectionist friend of mine who was short and slight of build. He once lost his balance as he was reaching to get the 6000 ft reel on the spindle on his tip toes. He fell backwards with the reel on top of him. I swear I tried not to laugh.

Oh and we don't run commerical schedules. Strictly CinEvents. If we run more than three shows for any engagement, it is unusual. No worry about LEDs getting shortend life by our runs....I will be long retired.

Now there is talk that they also may want to do some 3D films (just like that). These are the same people who heard about our very popular outdoor movies in the park and called me and asked if we could do it on campus -- during the DAY....with VIDEO projectors.

Back to this planet -- I explained that for 3D, they will need a new screen and interlock. I have a pair of old, and presumably working selsyns, but I would like to get synchronous motors and speed controllers so that when I am not doing 3D, I'll be able to use them for better control of unconformed silent films. I am sure this stuff will be way out of their budget, but seems that some of the board member and the chairman of the film dept got the bug to do 3D. When the higher-ups want stuff, they usually miraculously find the money. (When they tell you there is no money, what they really are saying is, there is no money FOR YOU!)

Anyway, thanks again.

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Monte L Fullmer
Film God

Posts: 8367
From: Nampa, Idaho, USA
Registered: Nov 2004

posted 04-13-2005 05:19 AM

quote: Mark Gulbrandsen
How stable a DTS system behaves is purely a matter of what equipment it is working with.

...On the comment from Mark above, here is a working layout of a DTS unit on a P35GPS machine.

Notice the black DTS guide rollers and how they are aligned to track the film through the reader. These rollers are aligned to give the tightest "S" loop though the reader assembly, thus ensuring the steadiest time code read thorugh the reader. Also, what handy with this roller layout, is that if the film hasn't any timecode information and DTS is the only digital format in that house, the film can be laced straight down to bypass the reader for optical usage.

Also, this is the main reason that AW3(r) platters are great for DTS usage - being with that three pinch roller assembly on the brain keeping the tension from platter to reader assembly constant.

Strong and other platter transports that have zero tension from platter to reader might have tendencies of DTS dropout due to the film isn't tight enough going around the scanner drum causing dropouts, or errors in timecode reads.

-thx Monte

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Brad Miller
Administrator

Posts: 17775
From: Plano, TX (36.2 miles NW of Rockwall)
Registered: May 99

posted 04-13-2005 05:29 AM

Monte, on that model Christie projector, you will find (if you don't already know) that the tightness of the belts will greatly affect the dts reader's ability to scan the track. So if you have one that is flickering and everything else checks out fine, remove the back cover of the projector and check the belt tension. [Wink]

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Monte L Fullmer
Film God

Posts: 8367
From: Nampa, Idaho, USA
Registered: Nov 2004

posted 04-13-2005 02:05 PM

quote: Brad Miller
remove the back cover of the projector and check the belt tension.

Boy! don't I know that one upside down, inside out, backwards and frontwards and all around the world with these P35's!

Why, we didn't use basement SRD readers with these things!

The other side of this complex, we have CAT-701's sitting on top of these P35's for the SRD playback. This side had the DTS.

When I would do the belt changes on these things, I made sure of the quarter-inch slack requirements on both belts.

I was told all about this from our chief engineer with this company and his choice of this tight "S" film path configuration, in which I have adopted completely.

He was an absolute perfectionist when it came to booth/machine setups and presentations! .... and a good teacher as well.

We'd never had any DTS dropouts with these machines.

..and I've heard that the CineX-35 machines took care of this basement SRD problem by eliminating that dbl sided belt, and using the round toothed belts.

thx, Brad. - Monte

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Antonio Marcheselli
Phenomenal Film Handler

Posts: 1260
From: Florence, Italy
Registered: Mar 2000

posted 04-13-2005 02:34 PM

Steve

I agree with you about the need of a new and more sophisticated DTS reader!

Ok, IF the timecode is printed correctly, IF the equipment is correctly installed, IF the film path is correct and does not wow the reader works properly with NO problems at all.

In Italy sometimes we received prints that had one or more reels with timecode not correctly printed but where a little adjustment of the lateral position of the big roller completely solve the read problems (I marked the original setting!). Then there are the tension issue, with a platter can be a problem.

Mains disadvantages with DTS were
- CDROM drives reliability
- CD shipment
- Eventually Timecode reliability

First two problems seems to be addressed (the first one with XD10, the second has been fixed, at least in my country).

Why doesn't build a better reader, a reader that can track the timecode track if it is not perfectly under specs and a bit misaligned, a reader that can have a sprocket that solve ANY tension problem, that performs an auto LED gain calibration and so on? I believe that it would be easy for them to build a device like this. This could help the entire system's reliability.

Ok, you can reply that a good print with a correctly aligned system does not have problems. True. But the real world is not always perfect! [Smile]

What do you think?
Ciao

Antonio

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99

posted 04-13-2005 07:03 PM

quote: Monte L Fullmer
..and I've heard that the CineX-35 machines took care of this basement SRD problem by eliminating that dbl sided belt, and using the round toothed belts.

Yes, the new Christie is without doubt the best bang for the buck in 35mm projectors today. They have eliminated and greatly simplified the belt system with round tooth pulleys and belts. All the flutter that used to be at the hold back sprocket on the P35GP is gone... gone...gone on the Cine-X35! Now you can use that basement reader with any problems and with very low error rates. The projectors also run much quieter than even a well tuned P35 does.

quote: Antonio Marcheselli
Why doesn't build a better reader, a reader that can track the timecode track if it is not perfectly under specs and a bit misaligned, a reader that can have a sprocket that solve ANY tension problem, that performs an auto LED gain calibration and so on? I believe that it would be easy for them to build a device like this. This could help the entire system's reliability.

Actually Antonio, I've given some serious thought to building a plate with dead rolling sprockets and tension arms that the DTS reader would mount to. This assy. would then attach to the standard DTS bracket. If I can do this for under 200.00 retail in small qualtities I may go ahead with it. The main cost though is the sprockets and tension rollers. The rest of it is really pretty trivial stuff.

Mark @ CLACO

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Antonio Marcheselli
Phenomenal Film Handler

Posts: 1260
From: Florence, Italy
Registered: Mar 2000

posted 04-14-2005 04:18 PM

Mark

Yours is a good idea. I remember Brad posting a similar one. I wonder why DTS are not thinking about that rebuilding the reader from the basics. I cannot believe that it is too much expensive...

Bye
A

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99

posted 04-14-2005 09:47 PM

Antonio,
I believe that a reader is about 750.00 U.S. dollars right now. If they made a better reader that was even double that price I would gladly spec them in. What I hate is the constant removal of the tiny cover screws to get at the adjustment pot and tp's. There is one local chain that has drilled a hole in the front cover ov all their readers for access to this adjustment, they also installed mini phone jacks on the front to plug a meter into. Speeds things up quite a bit. On another outlook the reader could also be much worse than it is!!

Mark

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Frank Angel
Film God

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

posted 04-15-2005 12:21 AM

New development: they are now saying that because we already have Kelmar red readers and with that came the power supply that will feed a Kelmar basement digital reader as well as the analog rr, they want to know why I am not spec-ing a Kelmar basement reader to utilize the existing power supply.

Although I can't find it in a search, I am almost sure I heard some one praising the BACP basement reader units over the Kelmar. Was that just the analog reverse scanners or both the analog and the digital BACP readers that were considered superior over Kelmar? From what you guys are saying here, I shouldn't feel threatened by a basement reader, so now the question is, should I opt for the BACP unit over the Kelmar and tell them not to get their panty-hose in a knot over a $50 power supply? Will a Kelmar basement unit do good by me or is it going to come back and bite me in the ass?

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Sam D. Chavez
Film God

Posts: 2153
From: Martinez, CA USA
Registered: Aug 2003

posted 04-15-2005 01:44 AM

Frank,

BACP does not make a basement digital reader, only a penthouse SR.D reader.

There is not a thing in the world wrong with the Kelmar digital readers, it's simply a matter of the service and repair issues already discussed.

I am not clear which version of a Kelmar reader you now have. If all you need to do is add the digital reader to the soundhead, it's a snap. I believe they made a couple of versions of the analog readers, some with brackets in order to be "SR.D ready" some not.

Give my friend Tom Mohr at Kelmar a call. He's a straight shooter.

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