jewelia (jewelia@erols.com)
Fri, 02 Apr 1999 11:30:45 -0800
sorry charles--i don't buy your experiments' results--i don't think the
methods--and this isn't putting you down at all--i admire your efforts and
your astronomical knowledge--but i don't think your procedures pass the test
of scientific rigor. don't despair, its a usual problem with science in a
complex universe...that's why some of us have turned to exhubert chaos
theory. i myself am a fan of entropy and encourage on its existence (i'm
convinced it is the theological nature of the heavens)
i've used mylar myself to adjust print times and contrast--print times i
think to matter relatively contrast-wise regardless and mylar blocks light
transmission of certain wavelengths more than others--its been used for this
on glass for a long time. if you are putting it between film and paper of
course you are losing contact to some degree and of course that can matter.
that is, mylar is a way to change the spectral character of your light
source and i have three different mylars to do that as well as some other
goodies--has little to do with pointyness--mylar matters and if a light has
a different spectral range than another, i would expect differences to exist
in the output effect of the mylar for that reason--the only difference being
the type of light coming to it to work with...so i think...more...
a point source is a relative thing--think like lens aperture. so when dan
points out that with a reflector it seems that there is more than one point
from which the light originates--he is right but that doesn't mean the light
is not what is usually meant by the "thumbrule for pointsources." for the
talk about the sun--the astronomers have correctly pointed out that even
though it is very large the sun is far enough away to be considered a point
source and will work as a point source at the upper reaches of the
atmosphere i am most confident; how some ever, at our meager cosmic ground
level there are a lot of molecular water-prisms, hydogen and helium atoms
that just can make photons scatter like the dickens, and all kinds of other
neat stuff up there that reflect, attract, repel, and make photons cough and
spew their way down such that at the ground--the sun is quite diffuse and is
no longer the effective source all by itself--everything is part of the
reflector and see the below distinctions (i am making a prediction and like
other mystics and fortune tellers practicing art -- i have my ways to
guarantee my success?) . in fact over here in the mid-atlantic region the
existence of the sun above the smog is a just rumor that most of us still
believe in but...who knows...this is why i journey to sante fe on occassion
to get a sense of the existence of the sun--makes one feel much more
satisfied to be thrown into such a modern planetary state. another way to
think about it---if sunlight were a point source at ground level--i would
suspect it would be very easy to simulate in the studio. of course exactly
how it behaves--contrast wise depends on the clearness, time of day. but no
matter, passing through the aperture, we have sunlight as a relative
pointsource on the film plane once more. to go on, i could talk of shadow
photons we theorize to exist--but they don't matter in regards to my print
quality either so i'll save those babies for more artistic statements of my
get a quanted creation.
Sources are considered point sources in general (this is a thumbrule--all
the usual assumptions and problems with universal categories of
generalization apply--but it is sometimes useful) if the distance between
the source and the target is more than half the radius of the light
source--the reflector would just increase the area of the light source--and
it is not true really that a bulb is a single source itself. generally,
three catergories of thumbrules are used to estimate the variance of the
intensity of the radiation types we consider and this extends far beyond
visuble light on both ends of the spectrum---plane, line, and point--planes
are complicated and broken down into subcategories--line sources behave
directly inversely proportional and point sources inversely and
exponentially by the square. other than intensity--given normal
assumptions. designers try to effect these characteristics (skew the
distribution somewhat) with reflector design and shielding--in some
cases--your typical enlarger--i agree that this can matter but i would say
it is more a factor of lens flare and i myself am skeptical of the talk
about dispersion within the film and paper that i used to read about
sometimes when i used to read the wrong zines--if you are a napkin and
equation person at the lunch table i suppose this can be interesting but as
an artist i just don't buy this as something that matters to me as an
artist--its not a matter of right and wrong now and again, i'm not an
absolute heretic--i'm just focused on making art and i weed out a lot of
extravagance--but not sequins--of which i am quite fond. i just can't
decide which goes better with santa fe -- thinking APIS blue or red? any
ideas would be appreciated? jewelia@erols.com
so anyway--charles--i am intrigued about talking differences in result from
various light sources--just skeptical that the why is all that simplistic
and important--so i really like dan's take and info on plate burners and
nu-arc glowing goddesses above the frame--light up my life--those things are
great ways to convert your darkroom to entreprise-like transporter rooms!
and i agree--fourescents are the way to go--you can adjust enough other
things to make what you want.
i gotta go make another fabulous mistress-piece myself--so take care, enjoy,
and don't let me cause you any frets my dear. i'm quite fond of starry-eyed
astronomicals...
warm regards and a brightly lit, evenly dispersed flourescent day to all
jewelia Margueritta Cameroon
aka: photyna modotti (i am convicned she taught ed everything he knew)
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