1 Mar
2005
1 Mar
'05
8:18 p.m.
On Tue, 1 Mar 2005 07:20:37 -0800 (PST), Vintage Computer Festival
<vcf at siconic.com> wrote:
On Tue, 1 Mar 2005, Ethan Dicks wrote:
> Agreed... I have an Olympus D10 I picked up a couple of years ago...
> one important feature is that it has an external trigger input for a
> "bulb". I used it to take pictures of the Aurora Australis
> (http://www.penguincentral.com/cgi-penguincentral/pix.cgi?target=2004)
Man, I have got to get me down to Antarctica some day.
It's an amazing place. I've heard that tourists pay between $25K and
$60K for trips to the Pole (the tourist companies have to haul each
gallon of fuel in themselves - there is no public infrastructure, just
what each government sets up for themselves). Trips to McMurdo are
much cheaper, and trips to the peninsula are cheaper still (few $K)
I'm sure this is a really stupid question, bit is
that greenish glow really what it looks
like in real life? Amazing!
It's not a stupid question... the camera sensor was open for 45-60
sec... the equivalent time exposure for the human retina is,
obviously, much shorter, more on the order of 1/30 sec (which is why
TV works and we don't see our lights flicker except under certain
circumstances). As such, while we are sensitive to green light over
other colors, and the auroral light _is_ green, it's so faint most of
the time that it's more of a ghostly grey, except during really good
solar storms. When the light is intense, it _is_ a stunning green,
with reds and other colors occasionally, depending on the energy of
the particles, the altitude that has maximal excitement, etc (Nitrogen
and Oxygen can glow different colors (red/green) depending on their
precise concentration and what quantum states are involved in photon
release).
When seeing "red" aurorae at Pole, the most common expresson are red
fringes at the bottoms of green curtains. I've seen red pillars in
Ohio, but those were caused by a different specific transition than
red fringes. One of the oddest ones I saw last year was like a tube
of Aquafresh had been squirted across the sky - horizon to horizon, a
narrow (twice the width of the moon) wavy ribbon that was green,
white, and red. I'd never seen the red that concentrated before.
I have a few other pictures that need to be tweaked before I can put
them up... the ones with some moonlight look like they were composited
from a day shot on the ground with a night shot in the
air - exposures
long enough to have the aurorae visible really accumulate even a
little bit of moonlight.
Unfortunately, I didn't take my 35mm (Pentax P3) out much - probably
only twice, and most of those shots have *huge* static streaks across
the film - like green lightning forks going from edge to edge of the
slide frame. They are caused by actual static discharges generating
light inside the camera. The static buildup is caused by advancing
the film in uber-dry air. :-(
-ethan