Here is the patent application showing a yet-another-diffractive-optics patent application, featuring 500mm and 600mm lenses.
US Patent Application 20180373004
Example 1:
- Focal Length: 487.49mm
- F-Number: 4.12
- Half angle of view: 2.54º
- Image height: 21.64mm
- Total lens length: 409.74mm
- Backfocus: 98.42mm
Example 2:
- Focal Length: 584.99mm
- F-Number: 4.12
- Half angle of view: 2.12º
- Image height: 21.64mm
- Total lens length: 474.74mm
- Backfocus: 109.42mm
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