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Author Topic: Focus Issues - Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 12-19-2008 08:22 AM                     Jeff....the simple answer to your question is that what you are REALLY focusing is LIGHT, not an image or the film. The film creates a shadow in the light that we see as an image. This is the same reason you see a fringe around the image when an aperture plate is inserted...you are seeing the light hit the aperture plate first, then the film. The amount of fringe can be affected not just be the distance between the film and aperture but also the reflector design (how straight the light rays are when they hit the aperture) and the lens (how is its inlet pupil designed IN RELATIONSHIP TO THE REFLECTOR design. If you had a poor lamp alignment you will be getting multiple light paths to the film plane and ultimately the lens...this will translate to multiple images on the screen or a soft/blurry picture. Steve  |  IP: Logged Jeff Else Expert Film Handler Posts: 125 From: Detroit, MI, USA Registered: Nov 2006 posted 12-22-2008 10:38 PM                     ahh, thanks!  |  IP: Logged

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