The HJ21ex7.5B is a production portable lens having the widest field of view among the standard telephoto series of lenses. It is a replacement for the highly popular HJ21ex7.8B lens. It a strategic member of the family of seven HD portable EFP lenses offered by Canon that collectively offers an unusually broad range of creative options.
This particular lens was optimized for the highest EFP performance. Its relatively large input section includes innovative optical compensation to reduce focus breathing to an extremely low level. It is intended for producers and broadcasters having as their foremost priority a long focal length capability, wide-angle field of view, and exceptional optical performance. This has been achieved in a modest 5.65 lbs overall package. The optional flexibility of Canon’s Crossover aspect ratio switching system makes it a superb performer for both 16:9 widescreen and standard 4:3 image formats.
ABOUT THIS LENS
The HJ21ex7.5B has an established track record as the long lens of preference in a wide variety of reality television productions.
Combining a 21x zoom range with generous wide-angle of 65.2 degree horizontal (for the 16:9 aspect ratio) this lens has proven to be a superb workhorse that can address a wide range of field production projects. It is noted for its unusually low focus breathing. Its 3-group focusing system minimizes chromatic aberrations at wide-angle operation.
The design optimization strategies sought a high and balanced MTF profile over the entire image plane at an approximate F4.0 aperture setting. Relative light distribution was optimized for F2.8 and above and this uniformity of brightness across the image plane combines with the high contrast and excellent picture sharpness to produce vividly clear HD pictures. Contrast was extended by superb control of black reproduction – with optical and mechanical design innovations that substantially reduced flare, veiling glare, and any internal reflections. Similar attention to minimization of ghost images and other highlight-related chromatic distortions caused by strong light sources on-axis and off-axis further extend the operational contrast range of the lens.