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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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