Most users of Optical Inspection equipment do not fully understand magnification. Most will say they want between 200X to 400X but have little if any idea what that translates to in image size. The following points should be very helpful in clearing up issues of magnification:
1. ABSOLUTE MAGNIFICATION should be the type of magnification specified.
2. ABSOLUTE MAGNIFICATION MUST reference the size of the monitor being used.
3. ABSOLUTE MAGNIFICATION is the diameter of the image being displayed divided by the diameter of the object being magnified.
4. ABSOLUTE MAGNIFICATION does not change the resolution of the image.
5. OPTICAL MAGNIFICATION is the diameter of the image projected onto the CCD camera chip divided by the diameter of the object being magnified.
6. OPTICAL MAGNIFICATION improves the resolution of the image.
7. ELECTRONIC MAGNIFICATION is obtained by masking off part of the displayed image and then re-displaying that image over the entire monitor. This is in essence "stretching" the image over a larger surface.
8. ELECTRONIC MAGNIFICATION does not change the resolution of the image.
9. RESOLUTION is a factor of the number of pixels contained in the image being displayed on the monitor. The more pixels in the image, the higher the resolution.
10. FIELD of VIEW is determined by how much you can see of the object being magnified. The greater you magnify the object, the less the field of view. You CANNOT make the core/cladding image larger and at the same time see more of the endface of the connector.
11. FIELD of VIEW is not changed by ABSOLUTE MAGNIFICATION.
12. FIELD of VIEW is changed by OPTICAL and ELECTRONIC MAGNIFICATION.
Copyrighted Nov. 26, 2000 Lyel R. Upshaw