Canon EF 24-70 f/2.8L is one of the cream-of-the-crop when we’re talking about Canon’s luxury lenses. Apparently, today its successor seemed to be making its way for a formal announcement really soon with Canon EF 24-70 f/2.8L II patent revealed–unfortunately without IS. Along were span of other lenses, 70-300 f/4-5.6L IS and 55-250 f/4-5.6 IS have also revealed in the patent. Check out the patent information after the cut.
Canon Rumors cited via Egami notes that the 24-70 patent shows possible performance issues. You can check out their findings here or the read the quoted analysis below.
The performance does not seem to be so good. The spherical aberration is delivered to less than +-0.2mm in all conditions at the outskirts. The astigmatism exceeds 1mm extremely badly in the short distance. The distortion is -4% of barrels type in the wide side. In the short distance, the distortion is +5% of lozenge type in the tele side. The chromatic aberration of magnification is corrected well.
Patent Information
- Patent Publication No. 2011-81062
- Published 2011.4.21
- Filled 2009.10.5
- Focal distance f=24.74 – 67.50mm
- Fno 2.92 – 2.91
- Half angle of view 41.17 – 17.77 deg.
- Lens length 206.42 – 177.53mm
- Back focus 38.43mm
- Aspherical 2
- zoom ratio 2.73x
- MOD 0.38m
- Focal distance f=72.21 – 299.52mm
- Fno 4.65 – 5.85
- Half angle of view 16.68 – 4.13 deg.
- Lens length 142.64 – 201.84mm
- Back focus 37.77mm
- Aspherical 1
- zoom ratio 4.15x
- MOD 1.4m
- Focal distance f=55.60 – 203.11mm
- Fno 4.16 – 5.88
- Half angle of view 13.80 – 3.85 deg.
- Lens length 162.05 – 202.41mm
- Back focus 58.79 – 82.03mm
- Aspherical 0
- zoom ratio 3.65x
- MOD 1.5m
Comments
Post a Comment