Film-Tech Forum ARCHIVE: Adjustable shutter blades

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Posted by Randy Stankey (Member # 64) on 04-17-2004, 11:50 PM:

My Simplex (PR-1003)has a shutter that can be adjusted so the blades are wider or narrower.

I've got a new lamp (Superior Quartz Prod.) and new lenses. (Isco Ultra Star HD+) I'm shooting a (approx.) 13' X 31' Cinemascope screen with a 2,000 watt lamp. I'm burning at 85-90 amps. That's just about as far as I can push her. (Use your "Scotty" voice.)

The light is pretty good. It has gotten a lot better with the new lamp and lenses. Now, I'd like to see if I can squeeze that last bit of light out of it.

There's still room for me to narrow the shutter blades by almost an inch and still have the aperture covered when the intermittent is at rest. What are the pros and cons, here?

Of course, I'll get a bit more light but it will put more heat on the film. It'll also make shutter timing that much more critical, lest I have problems with travel ghost.

Is the amount of light I stand to gain worth the potential problem? Or, should I leave it as-is?