What is an effective method to prevent air bubbles during manual film processing?

Gently agitating the hanger is an effective method to prevent air bubbles during manual film processing because it allows the developer and other processing solutions to flow evenly around the film. When films are submerged in the processing solutions, air can become trapped on the surface, leading to bubble formation. By gently agitating the hanger, you encourage the motion of the liquid, which helps to dislodge any air bubbles that may cling to the film surface, ensuring a smoother development process. This technique improves the overall quality of the radiographic image by preventing areas of insufficient development that can result from air being trapped under bubbles.

In contrast, shaking the film vigorously might cause more problems, as it can lead to additional turbulence that could create more bubbles or disturb the film emulsion. Holding the film still does not address the potential for bubbles forming around it, and submerging the film quickly can also contribute to trapping air if not done carefully. Thus, gentle agitation is the optimal choice for minimizing air bubbles during processing.