[time-nuts] finding time astronomically.

Brooke Clarke brooke at pacific.net
Mon Jan 23 18:10:08 EST 2012

Hi Chris:

I would say you want an optimum hole diameter for imaging the Sun.
Sort of like the f/100 school of photography.

For a few years I drove brass tacks into a hardwood floor at exactly noon where the tack was placed at the center of the 
Sun's image using 3x5 cards with nested ellipsis of different sizes with a small hole in the centers.  I choose the "pin 
hole" diameter that was slightly larger than the hole size needed for good overall focus.  If the hole is smaller than 
needed for good focus you are getting a much dimmer image and much larger and the image gets fuzzy.  For this 
application maybe a hole somewhat larger that still has the same peak intensity as the in focus hole.

Another idea would be to use a photo sensor to read the spots from a Dipleidscope.

Have Fun,

Brooke Clarke

Chris Albertson wrote:
. . .
> You don't want a pin hole or you'd be adjusting the aim every day

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