Transcript Sabatier Effect

ACVR Artifacts
Manual Film Processing
Clifford R. Berry, DVM
Adjunct Associate Professor, University of Tennessee
Veterinary Specialists Center, Maitland, FL
Manual Film Processing
Manual film processing involves dipping
the exposed film into tanks of
developer, fixer and wash.
The chemical are held in stainless steel
tanks.
The water should be running and
draining.
Temperature of developer and fixer
must be known for adequate
development.
Manual film processing
Developer
Fixer
Developer
Chemical must be stirred before
submerging the film into the
chemicals or there will be
heterogeneous development of the
film.
Stirrers should be kept separate.
Developer
Time-Temperature technique.
680F = 5 minutes.
A mechanical timer with a bell
is used to time the duration
of development and fixing
since the room will be dark
Film Hanging
The films are placed on
hangers to hold the
films within the tank.
Metal clips poke through
the film in order to hold
onto the film.
Be sure that films are not
touching.
If developing multiple
films, beware of safety
light fog.
Manual Film Processing
The edges of the film will be
punctured by the hanger
and can be used to identify
manual processed films.
Film corners may be cut.
Seen on all four corners.
Manual Film Processing
The films can be
air dried
Dryers are
available to
speed the
process of
drying films
Manual film processing
Tanks should be covered when not in use to
prevent the developer from oxidizing.
Chemical should be replaced on a regular
basis.
Film Too Light
Underdeveloped
Exhausted Chemistry
Underexposed
Manual Film Processing
Exhausted Developer
Developer time has to
increase to due
oxidized developer
and with prolonged
contact with the
developer chemical all
crystals (exposed and
unexposed) are
reduced results in
poor contrast.
Common Artifacts Associated
with Film Processing
Low fixer level
The entire film
was
developed but
the top portion
was not fixed
or cleared.
Chemistry Levels Uneven/Low
Low developer and fixer
level
The top of the film was never
fixed or developed
Chemistry Levels Uneven/Low
Low developer and
Fixer (higher level
than developer)
The green strip at
the top is the
portion of the film
not developed or
fixed
Development - Kiss Artifact
Cleared emulsion on
reflected light.
Matching radiograph to
accompany
Fixer - Kiss Artifact
Developed but
emulsion not
cleared so “milky”
or colored
appearance
(sheen) still
present at place
where two films
where in contact
within the fixer.
Emulsion Wrinkle/Peel
Emulsion wet
enough that
peels away
from the
film base.
Emulsion Peel
Lack of Wash - Fixer Oxidation
Formation of Silver Sulfide
Debunking Solarization
Solarization Process for making copy films by overexposure such that
a reversal of optical densities are produced when
exposed to light.
Rebromination hypothesis considered likely explanation
at this time.
Optical reversal occurs after prolonged exposure of the
film so that there is a reversal of the H & D curve.
Correct manual processing artifact = Sabatier Effect
Sabatier Effect
White light exposure of the radiograph while
in the developer (manual processing).
Results in the silver grains in the areas that
are “white” non-exposed becoming
developed to Dmax. The partially developed
areas are less affected by the light
exposure.
Creates characteristic lines of demarcation
called “Mackie lines.”
Sabatier Effect
Incomplete fixation
Colored Film
Pink – on view box
Greenish with reflected light
Due to exhausted fixer, incomplete fixation or insufficient
rinsing
Non Stirred Developer
Developer - Specific Gravity Effects
Developer Specific
Gravity will cause
the “strongest”,
non oxidized
developer to settle
to the bottom of the
developer tank.
Sight Development
Cathedral Effect
Film Fog - Safety Light
Manually processed.
Light leak or inappropriate
safe light in dark room.
Note the shadow (minus
density) created by the
film hanger.