MAKING THE DARKROOM SAFE
A darkroom should be exactly what the word implies - a room void of any light. Because panoramic and cephalometric film uses light emitted by the intensifying screens to expose the image on the film, it is important that your darkroom not have any lights that will expose your film. The easiest way to check your darkroom for any light entering from outside is to turn off all lights in the darkroom, including the safelight. Allow your eyes to adjust to darkness for a few minutes. Make note of any areas where you can see light in the darkroom. Some common examples of light leaks are found are around the door, ceiling tiles or light fixtures. All areas where you can see visible light entering your darkroom will impede your film quality. Any other equipment in the darkroom with operational lights should be relocated to another area if possible or have the light source covered. Automatic processors with operational lights are the only exception.

Any light entering your darkroom can fog the film. Fog can be thought of as background noise that affects the overall image of the film. The intensity of the light that hits the film as well as the length of time the film is exposed to the light can cause varying degrees of fog. A simple test will check your darkroom for fog conditions. Take a blank sheet of film and place flat objects, such as coins, on the surface. Allow the film to sit for two minutes and then develop as you normally would. If you can see the shape of the object on the film, you have a light source fogging the film.

SAFELIGHTING
Safelights provide lighting in the darkroom. But they only provide a short window of time before they will also fog the film. Safelights allow for approximately 2 1/2 minutes of handling time before fog will develop on the film. The safelight should have a Kodak GBX-2 filter or equivalent, be placed a minimum of 4' from the film handling surface and have a safelight bulb with a maximum of 15 watts. Safelight filters do fade with use and need to be replaced every three to five years.

MANUAL PROCESSING/DIP TANKS
Correct developing of the exposed film can not be overemphasized. Manual processing requires that you maintain active solutions by replenishing regularly, using the proper equipment, and following a standard procedure systematically.

A timer and thermometer are essential to manual processing. Continually monitor the developer solution temperature to ensure proper chemical activity. Once the temperature has been determined, an accurate timer is needed to process the film for the proper length of time. Consult the following developing time/temperature chart to determine the appropriate chemical temperature and processing time for the type of film you are using.

MANUAL PROCESSING RECOMMENDATIONS FOR EXTRAORAL RADIOGRAPHS
 

Follow the instructions on the containers to mix the chemicals properly. Use the correct amount of replenishing solution to maintain the level as well as the chemical activity. As a general rule, add eight ounces of developer daily to the developing solution. You may need to drain some chemicals out of the tank in order to do this. The solution level must cover the top of the film hanger. Chemicals should be changed every 3-4 weeks regardless of use since they will break down on their own. Broken down or “old” chemicals can not be replenished after 3-4 weeks of use.

Film hangers should be used to help film avoid making contact with the sides of the developing tank and other films. Film hangers also aid in film drying. It is important when loading the film hanger not to scratch the emulsive surface of the film.

Developing tanks need one-gallon inserts to process a panoramic size film. Tanks should have continually running wash water to maintain the developer temperature and flush away contaminated solutions from the wash tank.

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e-mail: tech-suppport@pancorp.com.