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RE: (meteorobs) photos of perseids
On 5 Aug 2001, at 10:41, Ulrich Beinert wrote:
> My primary goal is to get aesthetically pleasing images. Hard with the Moon
> shining, but the goal ist to have some pretty pictures of meteors.
> Besides, I've only used 200
> and 400 speed films in the past, so 3200 should capture many more meteors
> than I'm used to, even if the lens is sopped down one and a half stops. What
> do you think?
I dont think you will see any improvement using the 3200 film vs.
the 200 or 400 speeds. In fact, the results will likely be inferior.
There's a lot more than just raw speed when it comes to making
quality astrophotos. Resolution, grain and signal/noise ratio are the
primary determinants. All 3 of these factors are poorer with the
3200 film, particularly under the moonlit conditions for this event.
The lower resolution and coarse grain actually nullify a lot of the
gain in speed for recording point sources or thin faint lines. And
since the background will still be recorded proportionately faster,
the net result is a lower signal/noise ratio using the hi speed film
under such poor conditions. This is not surprising because such
type of film was designed for low light surveillance work, where the
goal is simply to record a rough image of extended objects, not fine
detail.
My advice is to use the 200 speed color film at full aperture. In fact,
if you can I would suggest you go to your nearest camera shop and
rent a 50mm f/1.2 lens for a day! The extra stop aperture in the
lens will be a great combination with the high resolution color film.
You will be able to expose up to 10-15 minutes for each shot,
instead of the ridiculously short 60 seconds for the 3200, thereby
greatly conserving film, which will make up for the cost of the rental
of the faster lens. The resulting images will be sharper and more
contrasty. In addition, since many brighter meteors change color
as they burn up, it will yield a much more interesting shot than on
b&w. Clearly, its the winning strategy!
Best wishes and good imaging.
Mike Linnolt
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