This is topic Specto shutters in forum 9.5mm Forum at 8mm Forum.
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Posted by Michael Wright (Member # 1387) on 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
Posted by Martin Jones (Member # 1163) on 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
Posted by Dino Everette (Member # 1378) on 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.
Posted by Hugh McCullough (Member # 696) on 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.
Posted by Michael Wright (Member # 1387) on January 17, 2010, 04:55 PM:
Thanks Hugh that explains a lot. MIKE
Posted by Josef Grassmann (Member # 378) on August 30, 2010, 12:07 PM:
similar to 16mm Bell & Howell made in the 60īs, Type 221 ??.
Gives a good increase in light output, bright screen.
Was also introduced on cinema projectors.
Posted by david lamont rough (Member # 2249) on 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
Posted by Dino Everette (Member # 1378) on 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.
Posted by david lamont rough (Member # 2249) on November 03, 2010, 04:46 AM:
thanks Dino,all done,Davy
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