What effect does poor film screen contact have on an image?

Poor film-screen contact significantly impacts the quality of a radiographic image. When the film does not maintain proper contact with the screen, it can lead to localized blurring, as the emitted light from the intensifying screen does not uniformly expose the film. This blurring occurs because the film is not consistently positioned to capture the sharpness of the image being projected onto it.

Additionally, this improper contact results in a loss of detail. The film may not adequately capture fine structures, which is critical in radiography for proper diagnosis. As a consequence, areas that should appear sharp may become indistinct and under-defined.

Moreover, the overall exposure of the image can be reduced, leading to decreased density. This happens because if the film is not in close contact, the light emitted from the screen doesn't sufficiently expose all areas of the film, causing some sections to appear lighter than they should.

In summary, poor film-screen contact produces localized blurring, a noticeable loss of fine details, and a reduction in the overall density of the radiographic image, all of which compromise the diagnostic value of the radiograph.