CAMERA LIGHT  SEAL PROBLEMS
The light seal on the above camera has crumbled away making the camera useless but is easily and cheaply replaced by the open cell foam                                     Various types of closed cell foam are used for the replacement of mirror cushions in many older classic cameras It is surprising how much light seal some cameras actually require and if any one of these seals fails then the camera is useless, but with the application of the open cell foam seal it can be cheaply restored. It is important to ensure that the film view window seal is intact as this is a common cause of fogging Certain makes of camera have a special cotton thread seal of about 1.5mm in diameter which runs in a groove around the perimeter of the body. This type of seal is not immediately obvious and  if it deteriorates can cause the film access door to rattle and not close firmly against the body of the camera causing light leakage Above shows the deterioration of the foam packing holding the prism in a SLR camera. A mere touch of the  screwdriver makes the old rotton foam fall away. If this is not replaced the prism will become mis-aligned and rattle. Unfortunately the shutter and prism seating also require a foam  damper which can rot away after time and will need to be replaced. Many older cine cameras use foam to hold the film and batteries in place. As can be seen above this quickly rots away, particularly if the batteries are left in the camera for any length of time