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The Darkroom. LeeAnn Pack DVM. The Darkroom. Everything should be keep clean Room should only be used as the darkroom Need plenty space – not bathroom Clean, dry, free of chemical hands Proper ventilation, humidity, temp. See the difference?. Safelights.
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The Darkroom LeeAnn Pack DVM
The Darkroom • Everything should be keep clean • Room should only be used as the darkroom • Need plenty space – not bathroom • Clean, dry, free of chemical hands • Proper ventilation, humidity, temp
Safelights • Illumination allowing people to see to develop film but will not cause film fog • Fog = unwanted blackening from light • Films sensitive to blue light amber • Films sensitive to green light red • Filters are used with a 15 Watt bulb
Safelights • Should be a minimum of 4 feet from the work space • Filters can crack so must be checked • Different set ups for safelights
Safelight Test • Know how to perform this test • Why might we do a safelight test?
Why to NOT do manual processing • Labor intensive • People cut corners and produce bad rads • Inconsistent • Time consuming • Maintenance • Messy
The Tanks • Developer • Rinse • Fixer • Wash
Getting ready for development • Check tank levels • They should completely cover the films • Check developer tank temperature • Stir the tanks to stir the chemicals • Use different stick (paddles) • Remove film from cassette • Hold only by edges
Then • Place film in an appropriate sized hanger • Small clips in corners pull film tight • Hook on bottom ones first
Develop It • Silver halide crystals are reduced to metallic silver • Put film in, start timer, agitate film to dislodge air bubbles from surface • 5 minutes at 68 degrees F • Time temperature charts • Time and temperature are opposites
Rinse It • Removed quickly from the developer and do not allow to drip back into developer tank • Allows for removal of excess developer • Agitate in the rinse for 15-30 seconds • Remove and allow to drain into rinse, not into fixer because it will cause fixer dilution
Fix It • Fix for twice development time • Agitate to remove bubbles • Remove and do not allow to drain back into fixer tank • Fixer stops residual development • Preserves emulsion and allows for film storage
Wash It • Need 10 water changes per hour • Film remains in wash for 15-20 minutes • Removes excess fixer
Dry It • Room temperature or in a dryer • Dryer will be quicker • Excess drying can cause cracking of the emulsion • Do not allow to touch during drying • Cut off the nipples from the clips • Ready for storage
Automatic Processing • All steps of the manual process are mechanically performed • Maintenance easy • 90 seconds to 7 minutes dry to dry time • More consistent radiographs • Less film artifacts • Reasonably priced
How It Works • Built in heating element • Feed tray feeds film into a roller system • Roller system takes film through each tank • Time spent in each tank is determined by the settings of the gears and speed of the motor • Ends at the dryer • Chemicals are replenished after each film
Patient Identification • Films are legal documents • Must be in the emulsion • Not written on afterwards • Hospital of Doctor name • Patient name • Date • Other info like breed, sex, age, owners name can be added but is not required
Lead impregnated tape • Info. written on tape and the place on cassette • Lead identification markers • Make up name stick on white tape put on cassette – lose them they are small • Photoprinter • Inside cassette, screen missing upper right hand corner • Info. gets stamped onto the film with little flash of light into the film emulsion
Film Storage • Organized manner • Labeling • Envelopes • Color coded • numbered
Film Artifacts • Not part of the animal being radiographed • Introduced during film handling, storage, during the exposure or during development • Are unwanted and do not contribute anything useful to the image • They are often distracting
Static • Rapidly pulling film from box or cassette • Low humidity – worse in winter • Should be 50-60% • Wool clothing • Screen cleaner • Trees, lightening
Fog • Chemical fog • Light fog • Light leaks • Safelight crack • Scatter fog • Film left in room • Storage fog • Outdated film • Darkroom temp high