8mm Forum: SPLIT GLASS - Removal or Replacement?

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Posted by Jon Addams (Member # 816) on September 25, 2012, 04:35 PM:

I have a couple of Sankyo 600 with badly damaged split glass in front of the light source.

Will it be damaging to the film if I were to remove the two pieces completely or should I try to find good replacements? [Confused]

Thank you

Jon

Posted by Hugh Thompson Scott (Member # 2922) on September 25, 2012, 04:54 PM:

I would imagine Jon that any glassware placed inbetween the
lamp and filmgate is there for a purpose, eg heat protection and
the removal of these components could be detrimental to your
film.My advice would be to leave well alone,unless replacing same.
The pieces of glass are meant to be split by the way for heat expansion.

Posted by Jon Addams (Member # 816) on September 25, 2012, 05:10 PM:

Thank you for your comment Scott.

Certainly the 2 pieces of glass were put there for a reason and yes they are there for heat protection and split to allow for expansion but it’s difficult to damage a film going by at 24 frames per second unless it stops in front of the light!

When this happens no glass is going to protect it and the frame will burn in a split second! [Big Grin]

I am sure someone here has removed those pieces at one time or another and may have the answer I am seeking. [Wink]

Jon

Posted by Steve Klare (Member # 12) on September 25, 2012, 05:56 PM:

Jon,

This is a classic Elmo ST-1200 question.

-basically if you never use single frame display all it does is reduce the light on screen.

The ST-1200 does fine without it, but I think you may be breaking new ground here!

Do you have a film you would be willing to consign to the flames? (In the name of Science!)

Posted by Hugh Thompson Scott (Member # 2922) on September 25, 2012, 05:56 PM:

With respect Jon, the gate plate is going to get very hot with no heat protection and this could lead to warping of your film.Why
would you want to remove something as integral as a heat shield?

Posted by Akshay Nanjangud (Member # 2828) on September 25, 2012, 06:09 PM:

Hugh, now you are scaring me. I got an ST-1200HD M&O without the lamphouse cover; have already played two features. Should I buy one of these covers?

Posted by Hugh Thompson Scott (Member # 2922) on September 25, 2012, 06:27 PM:

The way I see it Akshay, is that when these machines are put
together,no doubt certain tests will be done to ensure that your
films are not damaged during projection,remember that the
light is focused on that very small aperture and also heat.There
is a certain distance calculated for optimum light transmission
and heat dissipation will have been taken into account.They don't
usually fit things just for the sake of it,there is a reason,but it's
a risk I would not be prepared to take with my collection.

Posted by Graham Ritchie (Member # 559) on September 25, 2012, 06:57 PM:

Akshay

You mention no "lamp house cover". I would not use the projector until you get one, I am surprised that its missing.

Those lamp house covers, direct the airflow over the lamp and out the top, without it, that air and everything thats blowing with it would be going everwhere.

Regarding the removal of the glass itself, I dont like the idea of warm/hot air being bled of towards the gate area, rather than "all" of it blowing out the top.

Graham.

Posted by Akshay Nanjangud (Member # 2828) on September 25, 2012, 09:01 PM:

Anybody have that lamp house cover for me?

To add, I have two ST-1200HD projectors one of which is an M&O. The lamp house covers of these are different in that the M&O cover doesn't have a screw on top, it clicks shut on a small piece of metal. So I need a cover for the lamp that doesn't have a screw.

Posted by Janice Glesser (Member # 2758) on September 25, 2012, 10:20 PM:

Jon, for what it's worth...I have removed the split glass in my Sankyo 1000 and 2000H to get a clearer picture with no adverse effects. This was at the suggestion of the good Dogtor Frankarnstein. Of course the 1000 only has a 50W bulb...but the 2000H has a 100W bulb. It may be an issue with higher wattage bulbs.

Posted by Jon Addams (Member # 816) on September 25, 2012, 10:45 PM:

quote:
"-basically if you never use single frame display all it does is reduce the light on screen." - Steve Klare

quote:
"I have removed the split glass in my Sankyo 1000 and 2000H to get a clearer picture with no adverse effects."- Janice Glesser

Late last week I placed a telephone call to an old friend who's a SMPTE member, he returned my call just this evening and basically told me the same thing you both said - He removed the glass on several of his projectors, for better light transmission, several years ago and to this day continues to use them without ever having a problem.

My search for clean replacement glass is now concluded! [Wink]

Thank you all for your inputs.

Jon

Posted by Joe Balitzki (Member # 438) on September 26, 2012, 12:20 AM:

Inside one of my Elmos there was never any split glass in the lamp cover. Looking at the instructions there is no mention of it and its not shown in any pictures. Since the projector does not have a still function, its clear why Elmo left it out. So, as long as you do not use the still function you should be fine.

Posted by Akshay Nanjangud (Member # 2828) on September 26, 2012, 01:05 AM:

The common conclusion seems to be that split glass isn't necessary. So, the cover (black shroud like) still seems necessary and I should still continue looking for one. Anybody disagree?

Posted by Winbert Hutahaean (Member # 58) on September 26, 2012, 09:42 AM:

Akshay, since you say that there are two different lamp covers, could you post the picture of lamp cover you have one now, and I will post mine (if it is different), so we (and especially you) will have a better idea the one is needed.

Posted by Paul Browning (Member # 2715) on September 26, 2012, 09:55 AM:

Hi Jon , My two pence here, i agree with hugh 100% , its there for a reason , i feel sure its an ultra voilet filter and heatshield ,it reflects the heat from the lamp backwards and away form the apeture where your film will be travelling at 24 fps. This idea is used in the disco lighting effects during the 70's in the optikinetics solar 250's which use a 250 watt projector lamp but has a heat reflective piece of glass before the apeture gate for the same reason stated here.

Posted by Joe Balitzki (Member # 438) on September 26, 2012, 01:11 PM:

Akshay, Leon Norris can supply you with the cover that you need. And yes, you do need one for proper airflow and cooling of the lamp.

Posted by Paul Adsett (Member # 25) on September 26, 2012, 03:23 PM:

On the Elmo GS1200 the split glass heat filter is not present in the film path when the projector is running at normal 18 or 24fps. It automatically swings into the film path (via a solenoid) only when the projector is set to single frame.

Posted by Vincent Zabbia (Member # 2453) on September 27, 2012, 04:02 PM:

Akshay, I have a spare Lamp House cover..The snap in type with the split glass attached.. (not screw down) Let me know if you are interested. We can trade..thanks

Posted by Jon Addams (Member # 816) on September 27, 2012, 06:48 PM:

quote:
"On the Elmo GS1200 the split glass heat filter is not present in the film path when the projector is running at normal 18 or 24fps. It automatically swings into the film path (via a solenoid) only when the projector is set to single frame."

Hi Paul,

Live and learn - I have owned the GS-1200 for a couple of years, use it often and I never noticed this!

I really never has a reason to check until I came up with the defective glass on my Sankyo 600. [Embarrassed]

Thanks for the heads-up

Jon

Posted by Rob Young. (Member # 131) on September 27, 2012, 06:58 PM:

Er, on the ST, a heat sheild will swing into place when engaging single frame...

nothing to do with the split glass...

I've used many GS's; a split glass really swings into place? Wow..those Japanese engineers...

EDIT: Oh, I just can't help myself, gonna get a row going...

Do we need a split glass / do we need a heat sheild / can we prevent our films turning red? New post in General Jak.. "Over Engineering???"

[ September 27, 2012, 09:07 PM: Message edited by: Rob Young. ]

Posted by Rui Luis (Member # 3867) on January 27, 2015, 03:33 AM:

Hello, o need to change this glass of a Elmo K100 because mine have lot of fungus, someone have one of this to sell? or ideas for remove the fungus?

Thanks

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