Retired, 55 + years experience -- reside in Anaheim, California. My career -- photofinishing and manufacture of photo film processing and printing devises both optical/chemical and digital. I manufactured light measuring instruments used to measure films and prints. I manufactured control films to calibrate photo instrumentation. I worked for a time as quality control for Dynacolor,the film manufacturing arm of 3M making a Kodachrome knock-off color slide film. I taught summer continuing education classes at the Professional Photographer's of America School.