Added more sections but still in progress. Committing work without compiling new pdf

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Matt McWilliams 2022-07-27 14:03:04 -04:00
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@ -840,3 +840,97 @@ Any way, the two films ehare one exposure adjustment and filtration.
When films will be physically bipacked they should first be wiped with a lubricating film cleaner.
This is good practice for all optical printing when delicate originals receive heavy handling.
## EXPOSURE COMPENSATION
For superpositions from random pictorial originals:
For double exposures, the typical exposure adjustment is one stop of decrease from normal, during each exposure.
> With this adjustment a double exposure of picture A with picture A ie the same as a single normal exposure of A.
For bipacks there is no recipe.
Exposure adjustment is extremely dependent on which tones coincide with
which.
The adjustment is an increase from normal.
In ignorance of the originals (why?) and ignorance of the intentions (why?) guess 2 1/2 stops increase.
> No exposure adjustment can make a bipack of picture A with picture A the same as picture. A printed the same. But a gamma 1/2 bipack of
picture A with picture A is the same as picture.
## SPECIAL ORIGINALS
For superpositions not from random pictorial originals tones might not combine at all.
One image might fall on the other's black, or clear, and exposure compensation is different, perhaps unnecessary.
With special, rigged, originale superposition is not image combination in the earlier sense but image apportionment--implantings and supplantings.
The rules of tone combination still apply, but trivially, and a simpler logic prevails.
Double exposing from positives, where one image is black the other image appears, unaffected by the double exposure.
Where one image is very light it appears, hardly affected by the double exposure.
Double exposing from negatives, where one image (the picture, not the film) is clear the other image appears, unaffected by the double exposure.
Bipacking, where one image is any even tone, the other image appears, unaffected except for brightness.
The clear parts of one film are windows for the other film.
But it is possible, with enough extra exposure, to force one image through the blackened window of the other.
The most extreme cases of rigged originals involve high contrast masks, discussed below.
## TEXTURING
In a bipack, an image.of a plain white eurface, showing just its texture, imparts this texture to the other image.
## MULTI-EXPOSURE
Triple, quadruple, etc. multiple exposures are made similarly to double exposures.
If there would be 5 exposures from the same or nearly the same original, then each should receive 1/5 normal exposure.
From Chart C, 1/5 of full shutter equals `ND.70` compensation.
More likely the originals are special, and the compensation less.
## MULTI-PACK
Tripacks, quadripacks, etc. are unmanageable in simple optical printers.
For such effects intermediate prints must be made.
For example, to quadripack A,B,C,D make printed bipacks of A with B and C with D and bipack these two prints.
The order of the originals doesn't matter.
## NATURAL SUPERPOSITION
Of the three types only (1), the double exposure from positives, corresponds to possible camera original.
An original double exposure made from two real scenes is practically the same as a printer double exposure made from positive images of the scenes.
Type (2), the double exposure from negatives, is an artifact of the "log linear" response of negative films.
Type (3), the bipack, is an artifact of the transparency of film images, at least one of them.
Type (1) is nature's super.
Pressing one eyeball produces such superpositions.
## FLASHING
Double exposing an image with no image -- sere light -- lightens
(or with colored light and color print filma, colors) the blacks
and darker tones while having little effect on middle tones
and even lese on lights. It is8 not a true method of contrast
reduction.
Sepia toning can be simulated by both color flashing and color
filtering when printing B&W original onto color reversal print filr
A healthy yellow, magenta, or cyan flash when printing onto color
reversal film yields, respectively, the yellow, magenta, or cyan ~
image, as if this dye layer were prised from the original film.
There ie no photographic method for unflashing a flashed image.
There is image addition (double exposure} and image pultipliocation
(Dipack) and even image division (bipack of positive with
negative), but no image subtraction.
CONTRAST ADJUSTMENT Gammas add or subtract in a bipack, so bipacking
can adjust contrast. A bipack (printed gamma 1 or
Viewed raw) of an original with its duplicate is
like a double contrast original. <A bipack of an
original with its low contrast negative is like
~ a darkened reduced contrast original.
“fhe bipack of an original with ite high contrast
negative is like a Sabattier solarization!