P3D Re: Film speed ...

[Dan Vint <dvint@xxxxxxxx>]

Fuji Velvia rated at 32 and you are shocked!

The film speed ratings are an average setting that is supposed to give good
results (put you in the vacinity of correct exposure) for all of the cameras
out there from the latest fully automated 35mm camera\, to point and shoots,
to our older manual settings.

Take a look at the speed ratings, fstops, and shutter speeds on your Realist
or VM. Now look at what they are selling in the high end amature 35mm cameras.
You have fstops that can be set in 1/3 stop increments, and shutter speeds 
that a re virtually infinitly variable. With older cameras, 50 is about the
right rating for Velvia, for my other work I shoot it 1/3 of a stop under. Not
all emulsions are exactly the same. Many pros buy film by lot number so they
can test a roll of film and know what the proper ratings and color biases 
exist in that batch of film.

Photography is about taking suggested values from the film manufacturer, your
light meters and finding the exposure that you like! Take a picture at sunset
or sunrise and 3 frames exposed at 1/3 or 1/2 stop increments (on slide film)
will have dramatically different "feels" to the final result.  All 3 of them
may be perfect pictures.

There is a fair
amount of science and prescision that does happen in photography to get you
start and in the ball park for good photographs, from there it is up to
the user to experiment and find the rendition that they like with the film
and tools that they used.

Just to back all this up, take a look at Ansel Adams' Zone system. This is all
about calibrating (for B&W) the development and exposure times to get the
results that he considered optimum for his film, developer and lenses. This
all can apply to color film and slides. With Slides you have to get the 
exposure 100% right because what you got on the slide is as good as it is
going to get (minus digital manipulation) where b&w and color film you
have another chance to play with the numbers/settings during development and
printing.

..dan


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