[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]
Re: [ATM] Patterns of Testing: how we are messing up the hobby
I may have tried to reinvent the wheel a few times,
but I figured out that pneumatic tires and better
bearings were needed in order to get a better wheel.
I've learned a few things about mirror making:
Wood sucks as a material for focault testers. It
flexes, sucks up moisture, and doesn't always do what
I want it to do. Metals and plastics are superior.
Knife edges don't work on fast mirrors.
Hair isn't thin enough to work on fast mirrors.
Cheap LED's aren't bright enough.
The idea that I can cut a nice, straight line using an
x-acto knife on a microscope slide in smoke deposits
was only good in theory. The edges were really fuzzy
at 10x. It didn't make a good slit.
I haven't gotten around to using an interference test
to see what it would do on a concave surface. I guess
I'm rather lazy. That two-slit experiment that proves
that a photon or particle can be in two places at the
same time might be interesting as a mirror test, but
how I don't know.
Pitch laps are best if they're rather soft and very
thin. That technique that Tex' describes is messy and
difficult and produces a lap that might work for some
but hasn't worked for me.
Zen never mentioned anything about mirror making.
Neither did Confucious, Zoroaster, Jesus, Mohammed,
Nasrudin, Malaclypse the Younger, or Alfred E. Neuman.
Kevin Michael Zabbo (Soon to be formerly) of Eastern
Iowa
Seeker of the Darkness
--- Mel Bartels <mbartels@bbastrodesigns.com> wrote:
> Some observations that I will later weave together:
>
> Mirror making is one of the most wonderful endeavors
> in amateur astronomy,
> let alone any hobby. I liken it most to
> mountaineering and old time
> furniture making.
>
> Roughly half of all who attempt it have a bad
> experience and do not complete
> the mirror.
>
> Students in mirror making classses have high success
> rates and report
> satisfied positive experiences.
>
> A recurring and major complaint from amateurs on the
> ATM and other lists is
> disatisfaction with the mirror making experience.
>
> The stumbling block in the mirror making experience
> is figuring and final
> polishing.
>
>
======================================================
>
> Over the past couple of years, I've come to realize
> that there is something
> deeper to telescope making, imaging, amateur
> observations of objects, and
> mirror making. That's the basis of my talk a few
> months ago at NEAF, and
> will be the basis of my upcoming talks at ITS2005
> and Table Mountain Star
> Party this summer.
>
> Specifically in regards to mirror making, there is a
> "building" pattern that
> needs to be applied, adapted to each individual's
> situation, such that the
> person feels 'alive' or 'connected' to the
> 'building' experience. If any
> part of the building pattern or experience is not
> properly applied or
> adjusted, that part of the building pattern will
> feel dead, often resulting
> in abandoning the building project. This is true
> for all building patterns,
> whether mirror grinding, ultralight aircraft,
> furniture, you name it.
>
> We (and I certainly include myself) have no one to
> blame but ourselves for
> the lack of our fellow amateurs' success. That's
> because we often mess up
> the building pattern when it comes to figuring and
> testing, giving well
> intentioned advice that unfortunately does not hit
> the mark.
>
> We mess it up in several ways, but mainly, I've
> thinking of how we discuss
> and advocate mirror testing. We do it in a vacuum,
> without regards to the
> tester, his or her's environment and spiritual
> makeup.
>
> I said in an earlier email that there is no such
> thing as a 'perfect mirror'
> without taking into account the pattern of how the
> mirror is supported,
> secondary optics, how the mirror is used, its
> environment, the experience of
> the observer, and so on and so forth.
>
> Similarly, there is no such thing as a proper or
> best mirror test without
> taking into account patterns of 'testing'. It is a
> mistake to discuss
> mirror tests in isolation. We must consider the
> pattern of testing in
> totality. That includes everyone's unique
> circumstances and makeup. Each
> person will have difference circumstances that will
> result in at least
> slight, if not major, adjustments to the 'testing'
> pattern, in order for the
> person to 'come alive' in the test and feel
> 'connected' and 'positive'
> towards the test, with the ultimate result of
> creating an optic to view the
> heavens. If the person ends up feeling 'dead' or
> 'disconnected' in the
> testing phase of mirror making, then likely the
> project will be abandoned in
> frustration.
>
> To discuss pros and cons of particular mirror tests
> is missing the point.
> We need to discuss the 'testing' pattern, and how
> its various
> implementations help the test come alive, causing
> the mirror maker to feel
> connected, and achieving a happy result.
>
> That's why mirror classes have higher success rates
> than individuals in
> isolation. A good teacher adjusts the testing
> pattern for each student.
> For instance, I'll nuance the Ronchi pattern
> matching test differently for a
> beginner with a 6 inch f/10 compared to an advanced
> person with a 12 inch
> f/4. I will suggest a completely different
> implementation for the testing
> pattern for someone working on a flat.
>
> Hoped for results, the techniques of the tests, the
> individual: all
> necessarily will have unique implementations for
> every single individual.
> No two people should or happily could use the exact
> same testing process.
>
> Mel Bartels
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>
I published my first novel! You can get it here, from the publisher! http://www.publishamerica.com/Their search stringbox is on the right side about halfway down.search using my name: kevin michael zabboand it will take you right to my book page.The title is anna's blood, which also takes you there.Please order your copy soon! I love you!
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
_______________________________________________
ATM mailing list http://www.atmlist.net/