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Topic: The best 35mm projector

David Stambaugh
Film God

Posts: 4021
From: Eugene, Oregon
Registered: Jan 2002

posted 12-29-2006 06:31 PM

quote: Louis Bornwasser
"which problem do you want?"

I'll have to remember that one. [beer]

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Martin Brooks
Jedi Master Film Handler

Posts: 900
From: Forest Hills, NY, USA
Registered: May 2002

posted 12-29-2006 07:06 PM

quote: Will Kutler
Many decades ago products were made to last, and consumers kept their products for many years.

In the automotive industry Detroit would gradually release technology over a period of many years. With any product patent protection and having the competition reverse-engineer your product was an ever-existant problem.

If you're trying to imply that Detroit made cars to last, nothing is farther from the truth. After WW II, Detroit purposely built cars with built-in obsolescence and to avoid failure, people who could afford it traded in their cars every two years. It wasn't until consumers started buying superior Japanese cars in the 1970s that there was a perception that it was not normal to have to constantly repair a car.

But one difference between then and now is that it was easier to repair cars yourself.

In the 1950s, my family's very expensive Admiral console TV was in need of constant repair. I saw the TV repairman more often that I saw a doctor.

One area where I think things were superior years ago were items like semi-pro and pro cameras, many of which are still around and operating today (although most of those were German and Japanese.)

Another area where the quality used to be superior was furniture. But that's largely because it used to be made from hardwoods and today much is made from fiberboard.

People toss products today not because they're manufactured in an inferior way but because it's simply more cost effective to purchase a new one than to have it repaired. And repairs on so many products (esp electronics) are near impossible because of integrated circuitry and miniaturization.

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Steve Guttag
We forgot the crackers Gromit!!!

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

posted 12-29-2006 09:40 PM

Double shutters....

They do NOT offer more even light...just the opposite...they offer a hot-spotty light. They are more efficient and will allow MORE light than the same sized single shutter.

As noted, the double shutter system opens/closes the light beam twice as fast. However, it closes the middle off first and it opens the middle first. As such, the middle will receive more light for the eye to integrate.

If one were to plot the cycle of the double shutter system versus a standard shutter...the period would be the same (48Hz) but the time it is in the open position would be greater than for a standard shutter and the steepness at which it transitions between open and closed would be greater.

In fact, take one of those old solar cells you ripped out for red light readers, put it in the lens barrel. Hook it up to your trusty O'Scope and put a light pointing into the projector (or even the lamphouse but one need not go too crazy on the light source). Now run the projector and let the O'Scope show you what is happening.

The single-wing shutter is generally the best at any given size. It has even illumination and due to its speed being twice as fast as a conventional shutter, it offers all of the benefits of a double shutter but none of its shortcomings.

Steve

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Monte L Fullmer
Film God

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

posted 12-29-2006 10:15 PM

quote: Steve Guttag
The single-wing shutter is generally the best at any given size. It has even illumination and due to its speed being twice as fast as a conventional shutter, it offers all of the benefits of a double shutter but none of its shortcomings.

..why, once again, I love those Christie P35GPS units - with that single wing shutter design (just have to keep an eye on those shutter belts...).

In the 16mm world, why the earlier Bell&Howell projectors seems to have the best light with their single wing shutters installed - and with this design, the light is cut off twice per frame being that the third cut is during the pulldown stage.

-thx for the discussions on this shutter topic. Monte

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Steve Guttag
We forgot the crackers Gromit!!!

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

posted 12-30-2006 09:37 AM

Monte,

Christie HAD to go to the single wing shutter just to bring their crappy light transmssion up to Simplex/Century levels. The speed of the shutter (not the frequency) is determined by its size such that the blade velocity (v) = to its angular velocity (w) x its radius (r) (pretend my double-u is a lowercase greek omega). Christie's r is so small they had to do something to overcome there horrible flicker...all they could do was double the w to increase velocity.

Now take Mark's AA2...the radius of a Century blade (give or take) but single wing so its velocity is pretty darn fast! A standard Kinoton mechanical projector is also a single-wing shutter which accounts for its great light efficientcy and outstanding picture quality.

You like the Christie projector because that is what you know...spend some time with a Kinoton "D" series (or even an "A" series) projector and report back.

Christie's strength is in their precision in machining. As such, they can generally get things to align better than anyone else. I've changed entire heads and swapped turrets...never needing to align anything else...apertures and everything were right on the money. Most heads can't make that claim. I still have a Christie single lens holder that I use for alignments with them...even though it is over 20-years old...it will still pefectly point a laser and alignment projector right down the kazoo of the projector and it fits right on the same registration pins and holes that hold the current turret stop catch.

Steve

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Louis Bornwasser
Film God

Posts: 4441
From: prospect ky usa
Registered: Mar 2005

posted 12-30-2006 01:06 PM

Wonder why no one has used a pair of single wing shutters at 2880?

I, myself, do not think double shutters help enough to be worth it. Louis

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Monte L Fullmer
Film God

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

posted 12-30-2006 01:57 PM

Yes, I fully agree with you Steve, on your comments of my limited knowledge of the Christie - being that I've only worked with these units only for my 5 years that I worked with EDWS in my area here in this part of the country where the bulk of the theatres over here are using Simplex units...and what I'm working with now.

I do agree with you on the DP70/AA2 units since I've seen projected images coming from these projectors when it comes to light production.

But, I'd definitely will take up your offer on experiencing the Kinoton units and do report back to you on the results when that chance arises.

thx-Monte

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99

posted 12-31-2006 10:16 AM

quote: Louis Bornwasser
Wonder why no one has used a pair of single wing shutters at 2880?

Well, with the exception of the Christie which has its shutter safely burried behind 3/4" of solid alumnuim trap no other American made machine is actually built well enough to deal with even one blade turning at that speed let alone two of them, gear trains are just not up to it. I believe that death would lurk in any booth so equipped! You'd also have to convince American projector manufacturers to spend more than 69 cnets for a shutter blade. I certainly agree that double shutters are a mechanical waste and provide no real important gain... Except more breakdowns and service calls $$$.

Mark

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Steve Guttag
We forgot the crackers Gromit!!!

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

posted 01-02-2007 08:24 AM

Though greatly improved over the original P-35, the Christie gear train isn't exactly their strong area.

The Simplex has a better chance of going with a double speed blade than Century...which is already mis-disigned in their shutter department.

As to double shutter being "worth it"...it is strictly a matter of light...if you need the light, it is worth it...if you don't it is not. It is not a matter of opinion, double shutters are inherently more efficient with the light. You do NOT use the same shutters on a double shutter system as on a single shutter system...I want to say on a Century, you can eek it down by 20-30 degrees. This represents more than 20% more light than a Century with a 90-degree blade. This takes a theatre with only 12fL and puts them up into SMPTE specs without increasing the lamp size...which will likely cost them significantly more (both in lamp cost and shortened life).

In a Drive-In application, where light is always in a shortage, it makes quite a bit of sense.

Even the current FP75E from Kinoton is using a double shutter to get the light and the speed. It is a viable solution though, as I said, neither the best nor only solution for all applications.

Steve

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99

posted 01-02-2007 08:36 AM

quote: Steve Guttag
The Simplex has a better chance of going with a double speed blade than Century

I disagree. Not until the movement is redesigned(or the compensator to allow for better shock absorbtion) to allow for larger fibre gears. The slightest oscillation in the shutter would result in an arguement with the "fusable link" G-1836 gear. Had the Century been an oil bath machine and equipped with a conical shutter they'd have really had something there.

Christie has done more homework on their "Gear Train" and has switched to both composite teflon coated pulleys (and composite curved runners) as well as round tooth timming belts that are much larger than the old square tooth stuff.n To me the Christie still represents the most bang for the buck in U.S. made pojectors.

Mark

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Steve Guttag
We forgot the crackers Gromit!!!

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

posted 01-02-2007 08:52 AM

You can disagree all you want...you'd still be wrong.

Christie HAD to do more homework...look at where they started from...the P35 was a belt drive system gone mad. Most everything they have done has been in response to their original lacking design.

The Century gear train...in an oil bath...would still be a miserable design. It works despite itself but still with significantly higher failures in their gears (shutter, main drive...even intermittent drive) than other designs. An oil bath would help but it wouldn't overcome bad design.

The Simplex has the best chance at a single shutter redesign.

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99

posted 01-02-2007 03:10 PM

Humm, I don't remember saying the Christie was the best.... only that it gave the best bang for the buck. Of course they had to redesign again... and they will be redesigning it untill the end of film. Even the older Christies continue to give more reliable service over other American made projectors in todays typical booth that is run by monkeys. The Christie sound head in the later models consistantly gives better W&F specs than either the Century or 5 star are capable of. The P35GP models... well, I won't mention how many percent it actually is.... [thumbsdown]

quote: Steve Guttag
The Simplex has the best chance at a single shutter redesign.

Actually I think you misread my post. We do indeed both agree that the Simplex would need to be re-designed for a single blade shutter to happen... You said it yourself. A century in an oil bath would still be a great idea... anything to make it more reliable and worthy.

Mark

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Scott Norwood
Film God

Posts: 8146
From: Boston, MA. USA (1774.21 miles northeast of Dallas)
Registered: Jun 99

posted 01-02-2007 03:18 PM

I know that Steve and Mark aren't terribly fond of the Century design, but do the gears really fail that often when they are kept lubricated? I've never seen a stripped gear, nor have I heard of it happening in the recent past at any of the theatres where I have worked. The machines in question date from the 1940s through the 1970s.

I guess what I'm asking is whether the Century is really that much less reliable than an X-L/PR1014, assuming that both are properly maintained. So, is it? Or is the X-L/PR1014 just better under "real world" circumstances where maintenance is poor?

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99

posted 01-02-2007 03:27 PM

Actually Scott I am very fond of the Century projector. Used them on close to 40 dailies jobs myself and other portable units I built for customers using Century machines have seen duty on another 200 or so features. Also built the VistaVision projector out of a 4" Century C model and it runs flawlessly.... and doesn't scratch film like most other VV maachines do.

In the future Steve needs to state more than "I am just Wrong" or we can assume that he is merely speculating that I am wrong. I guess I can say that Steve wears pink underwear too but both statements are of course just hearsay. Let him explain why I am wrong via calculations. Of course we could do gear tooth stress calculations on the G-1836 but the teeth are so miniscule and weak that it would be a waste of time. So it is all just speculation about the X-L being able to run a double speed shutter. In relaity the X-L and Century gear trains are similar... both use orthagonal gearing, one with a fine tooth pitch and one with a corse tooth pitch. Both projector designs have gear pairs where the larger gear is turning a smaller gear... thats the bad aspect. What it all really boils down to is the truth that U.S. projector manufacturers just don't produce anything that is really all that good any more. Give me a good ole Super any day!

For me its been about 50/50 in reliability between Simplex and Century assuming both are properly maintained, we service about an equal amount of both. X-L's will suffer broken pad roller latch pins and gate/trap problems with the large asortment of gates and traps they conured up for it. Centurys will go through an occasional main drive gear or seized bearing. Both have their unique problems and good points. Neither will survive well if "let go". On the other hand the latest version of the Christie if let go keeps on running just fine till the shutter belt breaks. How long that takes depends on nnumber hours running time and how good of condition the pulleys are in. The new composition gears and belts for the Christie are supposed to afford a 5 year life span for the belts. We have Cine X-35's with belts that are just at 3 years old now so I think 5 years is believable.

That all said the DP-70 is still the best built most relaible projector ever made and with the lowest maintainance cost.

Mark

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Phil Hill
I love my cootie bug

Posts: 7595
From: Hollywood, CA USA
Registered: Mar 2000

posted 01-02-2007 04:36 PM

Ya know Mark, I don't know who's more of a BRUTE... you or Adam! [beer]

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