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


Hmm. That is so cool. But is there any problem with the fact that the
opposite sides of the slide are probably neither flat nor parallel? Guy
Brandenburg

Charles Mitchard wrote:
>
> 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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