At 11:10 5/22/02, you wrote:
This is probably a dumb question, but when people say "negative film has
more latitude than slide film", which stage(s) are they referring to where
you gain/lose latitude?
Latitude is the difference between how much light creates "pure white" and
how little creates "pure black" on the film. It is the ability to capture
detail in both highlight and shadow. The wider the separation between the
two (higher contrast), the wider the latitude required from the film to
maintain detail.
Having the widest possible latitude is not always a Good Thing. In low
contrast scenes it can make the image look "flat" and often
"muddy." Contrast between highlight and shadow is one of the visual cues
that gives two-dimensional graphic images a feeling of depth and dimension
(there are several others). It also enhances object/subject shape and
surface texture.
Negative film has wider latitude than transparency. Films such as Kodak
Portra NC, a color negative, and Kodak Tri-X have very wide latitude. It's
one of the major reasons both are used for portraiture and similar work
such as weddings. OTOH, commercial and professional daylight landscapes,
architecturals, and nearly all fine art photography is done using narrower
latitude film; usually using transparency.
*Real* photographers visualize the image (or types of images) first and
*then* select the tools to execute creating the mental vision, including
film, and film is selected for a number of its characteristics; two major
ones are saturation and *latitude*.
From the end backwards, it seems like:
1. once you've made a slide, you can't re-print it, so you're stuck with
whatever image is there -- with negatives you can play with enlarger times
to correct misexposure.
NOT . . .
Transparencies can be easily "duped" to create a negative or another
transparency. They're also *easily* printed using three major methods:
(a) Internegative:
The transparency is photographed using special internegative color negative
film (created for this purpose) and standard color negative "C" prints are
made from from the internegative.
(b) Direct:
The transparency is direct printed to a positive "R" paper using an
enlarger. Still considered the best method. Fuji "R" and Ilfochrome
(formerly Cibachrome) are two of the most common print papers used for
this. Kodak also makes an "R" paper.
(c) Digital Scan:
If the scan is high enough resolution, it can also be printed just as a
scan from a negative can be.
Over 900f my large exhibition prints are direct printed from
transparencies, and most of them are printed on Ilfochrome.
2. is there more/less room to correct things at the development stage with
slide film for whatever reason? (ie you can't push them or somesuch)
Transparency film can be pushed, and many of them (but not all) are quite
amenable to it. See specific data sheets for recommendations.
3. it can't be the original exposure stage, because slide film has tons of
range from light to dark, unless I'm missing something here?
It's just the opposite. Transparency has narrower latitude. Images will
be higher contrast. This demands much more accurate exposure
setting! Under nearly all conditions there's zero room for error; a 1/3
stop error can make an otherwise excellent photograph into garbage. Color
negative with wider latitude is much more forgiving . . . as are many of
the "consumer" print papers used. With many films it allows extracting a
*acceptable* photograph from a negative with as much as one stop of
exposure error (emphasis on *acceptable*). A print is a photograph of the
negative (or transparency). Just as the photographer can make errors in
focus and exposure, the "printer" can also make similar errors with print
density (same as exposure), enlarger focusing and color
balancing. Printing from transparency is much easier; the transparency
itself is a "witness" for print density and color balance; the print either
looks like it or it doesn't. Color negatives in particular are much
different due to the orange mask and negative colors; much is left to the
skill of the printer. It's one of the major reasons I quit using B&W and
color negative films some time ago, except for some special applications in
which the wider latitude of Portra or Tri-X is highly desired.
-- John
< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >
|