A method for modifying the spectrum of light rays passing through an objective lens to an electronic camera that includes providing an interference type filter within the objective lens. The subject seal secures a housingshaft area of a low or non-pressurized unit containing solid media where the shaft penetrates the machine housing and does not rotate but moves in multiple directions during normal operation. The emulsion is stabilized with an alkylene oxide containing emulsion stabilizer. Measuring an initial vibration may include using conditioning electronics in connection with the accelerometer.