At 20:24 6/6/99 , Gary wrote:
>I recall some discussions of meteor photography in the past but I don't think
>there was much technical advice. Anybody care to make some suggestions
>before I
>head off to the Gila National Forest the endof this month? We'll be
packing in
>on horseback and it will be my first wilderness overnighter in a very long
>time. I have available an original OM-2 as well as -2n and -4t but I suspect
>that this is not the subject to make automatic exposures of, due to the
dimness
>of the stars and meteors. So is it B exposures for how long at what aperture
>for say, Provia 100?
>
>Thanks,
>Gary Edwards
This time of year . . . take *plenty* of water unless there is a known,
working, *potable* water source there (or one that you have the proper
equipment to make it potable). Having done a *lot* of backpacking in the
Arizona wilderness . . . water is the *most* important thing in both high
and low desert. Humidity is so low you can dehydrate quickly and not know
it until you feel weak and queasy. If you run low clean pots and pans with
sand . . . yes, sand, it works better than a brillo pad and rinse out with
very minimal water to get rid of the grit. Been caught twice low on water
in Arizona . . . not fun . . . one time it took a day and a half to get out
and was sucking dew off of pine needles.
On the photography, I would be concerned about exposure correction for long
exposures beyond the film's reciprocity failure point. As you are chasing
meteors, color may not be that much concern, but films also can require
color correction beyond the reciprocity failure also if the different
emulsion layers fail at different exposure points. For two of Fuji's
professional reversal films:
FUJI:
Provia 100:
< or = 32 None
32 - 120 +1/2
120 - 480 +1
Over 8 min. Not recommended
Velvia:
Time(sec) Correction (stops)
< or = 4 None
4 - 8 +1/3
8 - 16 +1/2
16 - 32 +2/3
32 - 64 +1
Over 64 Not recommended
For other Fuji films . . . and color correction data go to the Fuji's UK
site (its not on the US site :-( )
http://www.fujifilm.co.uk/technical/division.cfm
You will need Acrobat for the data sheets in PDF.
For Kodak films, go the Kodak's site and hit their reversal film lists.
The data sheets are in html and downloadable PDF format. On Kodachrome and
Elitechrome, scroll down. On the left side look for "technical
information" and select it for the data sheet.
Kodachrome:
http://www.kodak.com/cgi-bin/webCatalog.pl?section=&cc=US&lc=en&product=KODA
CHROME+Slide+Films
Elitechrome:
http://www.kodak.com/cgi-bin/webCatalog.pl?section=&cc=US&lc=en&product=KODA
K+ELITE+Chrome+Slide+Films
Ektachrome (professional):
http://www.kodak.com/cgi-bin/webCatalog.pl?category=Professional+Color+Rever
sal+Films
Note that Kodak often omits reciprocity data from its consumer stuff. For
Elitechrome, the translation to their professional is as follows:
Elitechrome 100 = E100S
Elitechrome 100 Extra Color = E100VS
Elitechrome 200 = E200S
Elitechrome 400 = E400S
You will undoubtedly have to knit these super-long URL's back together as
they will wrap.
Other than that, take a telephoto, a wide angle, lens hoods for them, a
sturdy tripod and shutter release cable (with lock). For long exposures,
one trick to reduce mirror vibration is to place a hat or cap in front of
the lens, trip the shutter, lock it open, and then remove the hat or cap.
Then cover the lens again before closing the shutter.
See Note 16 on the following web page, it may help:
http://www.astronomical.org/alnotes/astroindex.html
This is from the following site:
http://www.astronomical.org/
-- John
< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >
|