To: atm{at}shore.net
From: Charles Mitchard 
Reply-To: Charles Mitchard 


Hi,
Peter Smiths (pjifl{at}bigpond.com.au) method of making a slit is easy. rub a
fine needle on glass or fine emery paper to get the finest point possible.
paint a layer of black paint onto a microscope slide and before it dries
hard scribe a line.
It may take a few tries to get it right, ie. the paint at the right stage of drying.
It then produces a very fine slit to shine the light source through. Charles

>Vladimir said:
>
> > I think that you can not make hair (wire) thinner or thicker at will.
> > It is related to the slit width and what you are blocking is slit image
> >  where it is sharpest ( thinnest). If you have fixed slit and use to thin
> > hair, some light will spill around it and nulling the zone will be less
>pronounced
> > ( contrast).
>
>Ahh, I see. I am constantly amazed at how much there is to learn.
>
>Now the question becomes how thin the slit should be, and how to go about
>making it. I've read in the archives about methods for making pinholes, but
>not much for slits. A pinhole would work pretty much the same, should it
>not? And perhaps a pinhole would work better with a tester that has the
>source and hair moving together on an arc, because the slit would allow
>light to pass through on more axes.
>
>Probably I'll try a pinhole first, layering aluminum foil and driving a
>needle through the layers.
>
>Thanks!
>MTB

I just got lost in thought. It was unfamiliar territory.

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