8mm Forum: Specto shutters

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Topic: Specto shutters

Michael Wright
Expert Film Handler

Posts: 184
From: Chorley, Lancashire, England
Registered: Dec 2008

posted January 16, 2010 03:27 AM

My Specto has a type of shutter I've never seen before. It is essentially a 2 bladed shutter, with one large section that covers the pull down. The second section is very narrow that barely shuts the light off, if at all? Does anyone know what the advantages, if any of this type of shutter? Thanks Mike

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Martin Jones
Phenomenal Film Handler

Posts: 1269
From: Thetford , Norfolk,England
Registered: May 2008

posted January 16, 2010 07:31 AM

The narrow section is intended to increase the "Flicker frequency" without cutting too much light. It would only really be effective at sound speed (flicker of 48 per second); at silent speed flicker would still be obvious.
Martin

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Retired TV Service Engineer
Ongoing interest in Telecine....

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Dino Everette
Phenomenal Film Handler

Posts: 1535
From: Long Beach, CA USA
Registered: Dec 2008

posted January 17, 2010 04:38 AM

I know the large section of the shutter is tied in very precisely with the pulldown of the claw..if they get out of sync you will get a ghosting of the image on the screen.

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"You're too Far Out Miss Lawrence"

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Hugh McCullough
Expert Film Handler

Posts: 156
From: Old Coulsdon. Surrey. UK
Registered: Oct 2006

posted January 17, 2010 12:14 PM

Whilst the above postings are correct for most shutters things are slightly different on the Specto.
Being a silent machine it should have a three blade shutter, but it only has two blades.
What happens is that the large blade covers the film during pull down, and then covers the frame twice during projection of that frame, thereby giving you the required number of flickers for silent projection.
The small blade is only there for balance.

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EIKI Ex 6100 xenon machine.

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Michael Wright
Expert Film Handler

Posts: 184
From: Chorley, Lancashire, England
Registered: Dec 2008

posted January 17, 2010 04:55 PM

Thanks Hugh that explains a lot. MIKE

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Josef Grassmann
Expert Film Handler

Posts: 190
From: Hennef-Sieg, Germany
Registered: Apr 2005

posted August 30, 2010 12:07 PM

similar to 16mm Bell & Howell made in the 60´s, Type 221 ??.
Gives a good increase in light output, bright screen.
Was also introduced on cinema projectors.

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david lamont rough
Junior
Posts: 5
From: GB
Registered: Oct 2010

posted October 18, 2010 04:59 PM

i have a specto 9.5mm,and on showing film,in the middle of the film projection there is a faint light the same width as the notches in the film but all the way down the frames,any ideas anyone

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Dino Everette
Phenomenal Film Handler

Posts: 1535
From: Long Beach, CA USA
Registered: Dec 2008

posted October 20, 2010 01:50 AM

The shutter is out of alignment, you'll need to run the projector a bunch with the side plate off, since this will be a
1) adjust
2) test
3) repeat until you get the desired results ...

There is a tiny little screw on the shutter. I would first try unscrewing the screw and sliding the shutter back and forth along the little spindle (this would be towards the lamp or away from it) You should be able to take care of it from this, if it doesn't it should clear up most of it you might just still see some "ghosting" on titles, the next step would be syncing up the large blade with the claw pull down.

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"You're too Far Out Miss Lawrence"

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david lamont rough
Junior
Posts: 5
From: GB
Registered: Oct 2010

posted November 03, 2010 04:46 AM

thanks Dino,all done,Davy

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