Reciprocity is corrected by longer exposures. I n some, (used to be
all), color films the different emulsion layers require different levels
of correction, as the layers have different reciprocity curves, which
caused color shifts. Film manufactures used to publish charts, well,
Kodak used to publish charts, I don't know about other manufactures.
On 10/12/2010 3:32 AM, Larry Colen wrote:
On Oct 11, 2010, at 3:49 PM, Matthew Hunt wrote:
On Mon, Oct 11, 2010 at 6:35 PM, Larry Colen<[email protected]> wrote:
Alternatively, is there a good/easy/cheap way to stack a bunch of (for example
10 second) exposures to get a much longer exposure with less noise and short
star trails? It would be preferable for me to do this in lightroom, but I also
have
photoshop.
I don't think that's a winning strategy with film. To begin with,
there's the technical problem of registering the images for stacking,
since they won't inherently be in pixel-perfect alignment. I would
imagine that the same kinds of feature-matching programs that people
use for panoramas could help with this issue.
Sorry, I wasn't clear. Image stacking with digital is the alternative to using
film.
I know about reciprocity, but don't know specifically how to correct for it.
With digital: longer exposures mean more noise
With film: longer exposures mean you need to expose longer.
Though, if it's a question of brightness rather than exposure period, maybe
it'd be less of an issue with stars than it would be for the landscape.
--
Larry Colen [email protected] sent from i4est
--
"His lack of education is more than compensated for by his keenly developed moral
bankruptcy."
-Woody Allen
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