Part 5: Optical Component Selection and Troubleshooting
Common Errors in Optical Component Selection
The diversity of optical components, coupled with historical issues from the era of image tubes, often leads to mistakes when selecting these parts. Here are three fundamental misunderstandings:
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Lens Format vs. CCD Format:
- Incorrect belief: The lens format and CCD format must be identical.
- Correct understanding: The lens format should ideally be larger than the CCD format because optical aberrations tend to appear at the edges of the lens.
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Focal Length Dependence:
- Misconception: If the lens format is larger, it requires a longer or shorter focal length.
- Reality: Focal length depends solely on the CCD format, working distance, and object size.
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Extension Rings and Depth of Field:
- False assumption: Extension rings influence depth of field.
- Actual effect: Extension rings reduce the minimum working distance.
Resolving Blurred Images
Blurriness in images typically stems from two sources:
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Lens Quality vs. CCD Performance:
Lower-quality lenses may not match the capabilities of modern CCD chips. For instance, Pentax M Series lenses are optimized for contemporary sensors, but wide-angle designs can introduce structural weaknesses. -
Incorrect Lens Mount Configuration:
This is a common cause of severe blurring. Follow these guidelines:-
C-Mount Lens / CS-Mount Camera:
Ensure no 5 mm extension ring is installed between the camera and lens. All Imaging Source CS-mount cameras come with this ring pre-installed. -
CS-Mount Lens / CS-Mount Camera with Extension Ring:
If a 5 mm ring was added, focus can only be achieved on close objects. -
C-Mount Lens / CS-Mount Camera:
This setup restricts focusing to very near subjects. For standard applications, use Imaging Source’s CS-mount cameras instead. -
“Sticking” Extension Rings:
Residual rings may cause unintended focus issues. Clean the components thoroughly if infinity focus is required.
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Last Updated: 2025-09-05 02:07:41
