در انتظار 100-400 جدید کنون
سلام
نسخه موجود : Current 100-400 f/4.5-5.6L IS Optical Design
http://cdn.canonrumors.com/wp-conten...ntoriginal.png
و نسخه جدید : New 100-400 f/4-5.6L IS Optical Design
http://cdn.canonrumors.com/wp-conten...0patentnew.png
با توجه به طراحی جدید ، به نظر می رسد رفتار اپتیکی بهتری را در لنز شاهد باشیم.
نقل قول:
Patent Publication No. 2011-180218
2011.9.15 Release Date
Filing date 2010.2.26
Example 1
Focal length f = 72.20 – 135.00 – 290.00mm
Fno = 4.20 – 4.67 – 5.86
Half angle of 16.68 – 9.10 – 4.27 °
Image height 21.64mm
Lens length 185.20 – 214.53 – 239.20mm
Back Focus 46.74 – 47.82 – 57.41mm
4.02x zoom ratio
Group 6 for each group
Positive and negative polarity positive or negative group configuration
Example 2
Focal length f = 102.20 – 200.00 – 390.01mm
Fno = 4.10 – 4.55 – 5.90
Half angle of 11.95 – 6.17 – 3.18 °
Image height 21.64mm
Lens length 228.18 – 258.83 – 288.12mm
Back Focus 51.23 – 54.42 – 69.84mm
3.82x zoom ratio
Group 6 for each group
Positive and negative polarity positive or negative group configuration
Example 3
Focal length f = 100.20 – 135.10 – 290.19mm
Fno = 4.36 – 4.47 – 5.81
Half angle of 12.18 – 9.10 – 4.26 °
Image height 21.64mm
Lens length 184.66 – 198.82 – 244.82mm
Back Focus 42.53 – 46.68 – 63.07mm
2.90x zoom ratio
5 groups, each group
Positive and negative group of negative polarity configuration
Positive-lead type zoom lens
High zoom ratio can be easily realized
Rear Focus
Can be miniaturized
Easy full-time manual
Suppressing the fluctuation of spherical aberration
Upon zooming, if you move from behind the eyes, counting the two groups, the greater the variation of spherical aberration in the focusing
On-axis beam angle θ the following equation:
θ = AISN (1 / 2 * Fno)
Spherical aberration is proportional to the fourth power of the high on-axis ray
In focusing heavily on the object side to move first, counting from one group behind, which varies significantly higher on-axis ray
Canon’s patents, and by fixing the first two groups, counting from the back of the eye movement to limit the amount counted from the first team back, suppressing the fluctuation of spherical aberration
منبع