Re: [APML]: Newbie exposure time questions...

[Richard Klappal <klappal@xnet.com>]

The Astro-Photography Mailing List
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The moon is under full, direct sun illumination, so the old "sunny-16" rule
applies -- 1/ASA @ f/16.  Times have changed, so ASA is now spelled ISO, so 1/200
sec @ f/16. (use 1/250).  Then you want f/4.5, so-- f/16->f/11->f/8->f/5.6->f/4.5
is about 3.5 stops, so 3.5 stops shorter exposure from 1/250 is around 1/2500
second.

Can't do, probably, and the moon is a bit low in albedo (reflectance), so try
1/2000 and/or 1/1000 second. Slower film will give you a bit more range control.
An ISO 50 film would let you work at +/- 1/500 second. These would be for a full
moon.  Partial phases can stand more exposure, and air pollution affects it too.
Bracket and experiment.

Rich


RMOLLISE@aol.com wrote:

> The Astro-Photography Mailing List
> ------------------------------------
>
> In a message dated 98-07-08 15:20:36 EDT, you write:
>
> << The Astro-Photography Mailing List
>  ------------------------------------
>
>  Use the light meter in the camera. The moon is big and bright enough to use
>  the meter and then bracket a couple of stops either side. >>
>
> Hi Guys:
>
> I might also mention that I've seen at least one freeware Windows application
> ('Astro-photo' is the title, I believe) which will calculate exposure times.
>
> Peace,
> Rod Mollise
> Mobile Astronomical Society
> http://members.aol.com/RMOLLISE/index.html
> (The Home of _From City Lights to Deep Space_:
> The Urban Oberver's Guide to the Deep Sky)