[ATM] Quartz test

[GARY FUCHS]

Thanks Mike,

Could you explain more about the collimated 24" diameter beam and how that ends up being a point of light? There's probably something simple I'm missing...

Could a plain laser be used instead?

Thanks,

Gary Fuchs


>
>Gary,
>
>GARY FUCHS wrote:
>> Thank you for the photos and explanation. Your site's been helpful
>> to me with several things. I hope you don't mind some questions:
>> For the transmission test with the 4.25" scope, how far away is the
>> quartz from the scope and laser? Does it matter? Do you need to
>> move the quartz to have the laser go through different areas? I'm
>> assuming you don't view the laser/star image directly - is that
>> correct? Also assuming the laser isn't centered - does it matter
>> where it's positioned as long as the beam clears the spider?
>
>The collimator puts out a 24" diameter beam of collimated light, that 
>is, light that is parallel, like star light.  The 4.25" sits in front 
>of it, collecting a small portion of the beam to form a "star" image. 
>  I put a ronchi grating in the focuser to get the ronchi image later 
>in the page.
>
>The quartz was right in front of the 4.25" as an optical window would be.
>
>You can view the star image directly with a welding filter and an 
>eyepiece.  It is not bright enough to damage vision, but it's not 
>pleasant to view directly.
>
>	Mike Lockwood
>