Chromatic Aberration
Chromatic aberration is a condition in which the red, green or blue light that passes through the lens of the camera appears to be spread out over a wider area on the film than it would appear to be if the light were in focus.
The two most common causes of chromatic aberration are lens imperfections (defects) and improper use of the lens. If the image appears to be out of focus, this means that either the front or rear element of the lens has some type of distortion and/or that the lens itself has been misaligned.
Fix Chromatic Aberration
To correct chromatic aberration, the focus mechanism of the camera must be adjusted until it is in focus. Once the focus is set, press the Shutter button and open the lens completely. Then, while looking through the viewfinder, focus on a nearby object, and press the Shutter button halfway. A split second after you release the shutter button, move the lens away from the focal plane to one side. The split second allows for the camera to record the actual position of the image on the film and allows you to see the entire image, including any spots of chromatic aberration, in the viewfinder. When you are satisfied that the image is sharp, rewind the film and take another picture, this time moving the lens back towards the focal plane.