Re: [APML]: Lunar Occultation of Aldebaran

[RMOLLISE@aol.com]

In a message dated 98-02-24 04:04:17 EST, rwhigham@mindspring.com writes:

<< Hello,
 
 Just after Sunset (at my location) on March 4, Albebaran will be occulted by
 the first quarter Moon.  I'd like to capture the event (just before the
 occultation), but I'm aware of (1) the differences in brightness of the
 Earthshine and the first magnitude star, (2) point source with an extended
 object, (3) an acceptable image scale, and (4) the relatively bright sky.
 
 I'm considering using my C-11 with a f/5.6 telecompressor.  Has anyone
 already worked out a  film and exposure time?
 
 Thanks,
 
 Russell >>

Hi Russell:

This is definitely doabable, but as you've noted, the problem is exposure. If
you expose for the star, the Moon is burned out. If you go for Lunar detail,
you risk losing the star. Assuming you want a 'pretty' picture, you'll want to
use an exposure that doesn't overexpose the Moon; Aldebaran is quite bright so
it shouldn't be much of  a problem. So...exposing the moon normally for you
with an f5.6 reducer in place will mean an exposure of about 1/500 of a second
with 400 speed film. My suggestion is to load up with 36 exposures and bracket
the hell out of it. I have had some success in the past with occultation
photography, but now only do video--it's easier and just works better!

Peace,
Rod Mollise
Mobile Astronomical Society
http://members.aol.com/RMOLLISE/index.html
(The MAS Web Page)