Film-Tech Forum ARCHIVE: Simplex E7 question

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Posted by Pete Lawrence (Member # 130) on 03-03-2000, 08:27 PM:

I have a question about ancient history someone here may be able to answer. The Simplex E7 manual (available on this site)shows two shutters, one between the lamp and the film as usual and a second mounted out in front of the lens. Both rotate in the same direction on opposite ends of the same shaft. Any E7's I've seen in the past (including the ones I have) had the front shutter assembly removed. The only hint it was ever there is the extra long shaft sticking out the front. What was Simplex trying to do with this configuration?
Here's my guess as to what they intended, let's see anyone has a better answer. The two shutters, in effect, work the same as two counter-rotating shutters next to each other or a barrel shutter. Fewer degrees of rotation are required to blank the light and as a result longer light-on time. Something important back when drive-ins needed to squeeze all the light they could out of their arc lamps. Anyone got a better idea?

Thanks,
Pete

Posted by Gordon McLeod (Member # 33) on 03-03-2000, 08:48 PM:

You are basically correct
they had to be removed to accomodate most cinemascope adapters
Because the second shutter is in front of the lens it does the same effect as counter rotating shutters in the brenkert and century
because the light beam has been inverted
It is also usuable in a narrow range of focal length of lens as the angular cutoff vs RPM is dependent on the angle of the cone of light

Posted by Robert Throop (Member # 61) on 03-05-2000, 11:23 AM:

Brenkert did the same thing with their BX62 which was a BX60 with front and rear shutters.

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