A new patent showing the 600mm f/4 optical formula. Is Canon already working on the replacements to the current super telephoto lenses? It's quite possible! Although I suspect we're talking 7-10 years from now. These sort of patents could also be for technology that will appear in other lenses. Such as the upcoming replacement of the EF 800mm f/5.6L IS.
I do expect we'll be seeing more DO lenses in the future. There seems to be an awful lot of patents for DO optical formulas. I suspect the cost of production is the hinderance to bringing these lenses to market at the present time. We already have $11,000 200-400 f/4 lenses and $18,000 800mm lenses. I suspect we're at the ceiling of what people will pay for a lens…. or not. :)
Patent Publication No. 2014-26210
- Publication date 2014.2.6
- Filing date 2012.7.30
Example 1
- Focal length f = 588mm
- Fno. 4.12
- Angle of view 2ω = 4.22 °
- BF 56.0mm
- Total lens length 374.7mm
- Inner focus
Example 5
- Focal length f = 588mm
- Fno. 4.12
- Angle of view 2ω = 4.22 °
- BF 55.0mm
- Total lens length 343.5mm
- Inner focus
- Diffraction optical element
- Effect of the glass material
- Fluorite (Fluorite)
- In the long lens fluorite + total length, correction of chromatic aberration is easy
- In short lens fluorite + total length, correction of chromatic aberration is difficult
- Diffractive optical element (DOE)
- Diffractive optical element can be corrected if the chromatic aberration
- Flare caused by light diffraction
Source: [EG]
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