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Re: (meteorobs) Rotating shutter RPM's
George,
I think you are right. You want the fastest strobe rate that will freeze
the marked blade in a single fixed position. From your data I would say
1150 is it.
---
Bill Tschumy
Otherwise -- Austin, TX
Creators of Artificial Life
bill@otherwisedot com
----------
> From: GeoZay@aoldot com
> To: meteorobs@latradedot com; jrendtel@aipdot de
> Subject: (meteorobs) Rotating shutter RPM's
> Date: Tuesday, August 27, 1996 10:45 PM
>
>
> Okay, today I brought home my rotating shutter and stroboscope and did a
> series of tests. I marked one blade as suggested by Wayne Hally.
> Apparently this suggestion will enable some interpretations. The
> stroboscope results with RPM's and how the marked blade appeared on a 2
> bladed shutter are as follows:
>
> 450 RPM's = Showed only 1 blade marked.
> 650 RPM's = Showed the marked blade appearing on both blades.
> 1150 RPM's = Showed only 1 blade marked.
> 2300 RPM's = Showed the marked blade appearing on both blades.
> 4400 RPM's = Can't freeze shutter to show only 2 blades, but does freeze
4
> appearing blades that shows the marked blade on all 4 blades.
>
> In light of this test, my hunch that the shutters correct RPM's is either
450
> or 1150 RPM's...I'm leaning in favor of the 1150 RPM. The 450 seems to be
a
> too slow of a number for the fan motor. If the 1150 RPM figure is right,
> then at my observatory, the apparent correct RPM's must be near the 1250
> figure and that my 2500 RPM is the incorrect harmonic. Any help in
> confirming my hunches here will be appreciated.
> George Zay
>