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photo strategies for Leonids '00? (was Re: (meteorobs) DMS ready for take off to the Leonids 2000

Casper ter Kuile wrote:

> Hi All!
>
> Members of the Dutch Meteor Society are now fully prepared to observe the
> Leonids 2000 from a location somewhere in western Europe.
> In fact three separate expedition are beiing organised to maximize the
> change one of the DMS-groups will observe the outburst.
> One group Peter Bus, Klaas Jobse and Jaap van 't Leven are heading to the
> Algarve in southern Portugal.
> Another group among them Hans Betlem, Michelle van Rossum are Pavel Spurny
> will observe the Leonids from Spain as they did last year.
> The last group anxiously waits in the Netherlands and searches the internet
> for places in western Europe where they have fine clear skies to observe
> the Leonids.
> We will let you know by e-mail what is going on live from our observing
> site by GSM.
> Our DMS-website at http://www.dmsweb.org now is prepared for the Leonids 2000.
> Very first observational results will be published here.
>
> Best wishes and clear skies to all,
>
> Casper.
>

 I would like your input (& from anyone else) on *strategies* for photographing
the Leonids, with the last-quarter moon near the radiant.

 At 1st, I figured meteor photography was an impossibilitiy, given the moon
interference.  So, I decided not to do anything for 2000 Leonids.

On 2nd thought, maybe no.  There actually, may be some "clever" tactics to use:

1) use short exposures (i.e., prevent the moonlight from saturating the sky
back-ground density on film).  Say 2 min exposures on 800 asa film (just a
guess).  But, that would eat up a roll of 36 exposure film in 1 hr 12m.  Do that
all night (5-6 hours), that means 4 rolls/camera.  Since I use a bank of cameras
(3 on 1 mount, 3 on a 2nd mount, 3 on a 3rd mount), that could get expensive.
Over 2 nights, Nov 16-17 & Nov 17-18.  (Last year I spent over $300 on film &
developing costs, for 2 nights of meteor patrol photography!!  see
http://www.comet-track.com/meteor/leonids99/leonids99.html).

 I guess I could back-off, & use less cameras.  But, that compromises my blanket
approach ("covering the sky")

2) go for earth grazers, near midnight (when Leo rises at my 34 deg N latitude).
(The half-moon is near the horizon, so the sky isn't that light-polluted).  Then,
I can get meteor shots with semi-darksky conditions (shows the Milky Way,
deep-sky objects.)

3) use big aperture scope (to get meteors, since point-source exposures are
function of aperture), with slow f-ratio (to "knock down"  sky-background fog).
But, this means very long focal-length lenses.  This minimizes chances of getting
meteors.  Contradiction.  Paradox.  No solution?


For 1), has anyone come up with a formula (ASA, f-ratio, lens diameter, exposure
time), that is sky-background limited for half-moonlit conditions?  I can figure
this out, by just going out & testing (long trip, hassle, $$, etc.)

(example)
The Geminids '98, had a crescent moon come up in the east, ~4am.

http://www.comet-track.com/meteor/geminids98/16mm/16mm_36.jpg

 I backed off my exposures to 5 min (instead of 15 min, moonless sky), 1000 ASA,
f2.8.  But this year, there will be a half-moon, so I would have to go less
exposure.  2 min?  3 min?


Given the predictions, what are the chances of "fireballs" for 2000?  ('98 was
noted for the quantity of fireballs.  see
http://www.comet-track.com/meteor/leonids98/leonids98.html).  '99 was
disappointing..I spent all that $$, the photos paled in comparison to '98.


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