American Cinematographer - May 2000 - 121

it

much

finer-grained product."
upgraded to the
Vision family, the 250D 5246, stands
out among its Vision counterparts in
that its prior incarnation, 5297, was a
pre-EXR emulsion and didn't include
T-grains in its structure. Powell notes,

performed months of lab work in
order to generate the data on which
we
performed our analysis.

"5297

out

a

The final film

was

introduced in the late

1980s and had
D

cube-shaped, 3crystals. Thus, when we launched
more

the Vision 250D 5246 stock

-

which

introduced

T-grains to the emulsion,
as well as improvements in
light effi¬
ciency and a reduction in the scatter¬
ing of light - what customers saw
was, in effect, a fwo-generation leap in
technology between the two films."
Powell

further

notes

that

"daylight films are designed some¬
differently than tungsten films.
Typically, films with a daylight
balance have a slightly different
sensitivity in their color records -
what we call spectral sensitivity. With
a
tungsten film, the emulsion has less
response to blue-light energy than
red; this means that you have to have
larger blue-layer silvers in order to
produce a neutral image in tungsten
light. Daylight has more blue-light
energy than tungsten light, so with a
daylight-balanced product, you can
use a smaller blue
layer. [More
uniform color sensitivity] affects
how other light sources [of different
color temperatures] record as well,
which is why 250D handles mixedlighting situations so well."
what

As detailed in last month's

article, all of the emulsion
conducted

tests were

35mm

negative alone.
accompanying chart (see fold-

The

on

section)

was

created for

our

data

sheets

to

ments

would be taken. Information

reference the

primary areas
where exposure-control measure¬
recorded for each batch of itera¬

was

tions and for each emulsion.

the

tests on

was

seated

all

During

emulsions, the model

just behind the reference

charts, which included

a

Kodak 18%

card (at position "L" on the
chart), a seven-step gray scale ("I"), a
gray

MacBeth Color Chart

("K") and

a

Sharpness Indicator created by Ivan
Putora,

as

well

as

an

information

("B") and white bleached muslin
("E") to provide "textured black" and
"textured

white"

references.

(Incident meter readings in these
areas were

1 Vi

stops under key level.)

Immediately behind those areas (on
the left and right sides of the frame)
but farther off in the background, we
placed a large, 12' by 12' grip solid
("A") and a 4' by 8' sheet of poly¬
styrene board ("F") to provided
references to "pure black" (the inci¬
dent meter reading in this area was 7
2fi stops under key) and "pure white"
(three stops over key) contrast

process; one

and I conducted exhaustive research

ment;

and

consulted

several

rolls of the

for

a

same

three

sepa¬

emulsion:

one

one-stop, pull-development

for normal develop¬
for a one-stop, pushdevelopment process. The ISO for
each emulsion was determined by
and

one

the manufacturer's recommended
base

were

Denis
all familiar

with

rating. For pull- and push¬
processing, the emulsions were rated
one full stop under and over their
respective ratings (e.g., for Kodak's

putting different stocks through
also relied upon the
expertise of Tom Kuhn and Mary

Vision

500T

Quan at Deluxe Laboratories, who

process

iterations

their paces. We

May 2000

rate

on

Robert Primes, ASC and

Lenoir, AFC - who

112

exposed three times

tests was

highly
respected directors of photography
including Allen Daviau, ASC,

-

were

level that matched the

key source

level. Their illumination
altered

during the test

would remain
level

as

at

the

the lens iris

for each of the

all lit

not

was

that they

so

same

exposure

setting. Lighting

tests was

achieved

through the use of tungsten or HMI
sources, depending on the emulsion's
color-temperature balance (see light¬
ing diagrams for details). Color
temperature was carefully monitored
and altered (with Lee CTO and CTB

possible
for this inspection of motion-picture
camera
negatives, fellow AC writer
and cinematographer Jay Holben
as

The reference cards
to a

correction

Each iteration of the

accurate

were

we

Immediately behind the model,
hung a strip of black Duvetyn

extremes.

as

rolls

slate.

THE TEST

To be

ISO

rating of 500; the pull-process
exposed with an ISO rating
of 250; and the push-process rolls
were
exposed with an ISO rating of
1,000). Using this method, we could
keep the lighting setup constant for
each phase of the emulsion tests, and
adjust exposure levels consistently
using the lens T-stop.
an

5279, the normalwere

exposed with

filters) to fall within an
overall tolerance of +/- 50K of 3,200K
for the

tungsten-balanced stocks, and

+/- 50K of 5,500K for the daylightbalanced stocks. Temperature measure¬
taken with

ments were

Colormeter II from the

Minolta

a

position of

the model.

Incident
taken with

a

and reflected
taken with

a

meter

readings

Minolta Auto
meter

Minolta

were

meter

readings

III,

were

Spot F meter.

All calibrations for the meters had

been

completed within the previous
days by Quality Light and Metric
in Hollywood. All of the tests were
photographed with a Panavision GII
30

camera

and

50mm Primo lens.

a

Lighting was provided by Hollywood
Rentals, and the laboratory work was
performed by Deluxe Hollywood.
After the test was completed,
all of the rolls

were

taken

to

Deluxe

for

processing. Pull- and push¬
processing was precisely calibrated to
yield a true one-stop rating, per
Deluxe's standard procedure. Each
iteration on the negative was then
examined

on a

densitometer (read¬

ing the emulsion's recorded density
on the Kodak 18%
gray card at
exactly the same frame for each iter-
American Cinematographer - May 2000

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