The DIGI SUPER 23 xs is a new cost-effective member of the HDTV studio lens family offered by Canon.
This XJ23x7BIE-D lens is intended for broadcasters and producers having as their foremost priority excellence in picture quality in a studio high definition lens-camera imaging system while also seeking a cost-effective investment. Most of the major camera manufacturers now offer two tiers of HDTV studio cameras (both large and portable) that offer flexible choices in terms of performance/features and costs. With this new XJ23xs and the established flagship XJ25xs lens – Canon has now compatibly matched this HD camera hierarchy with two distinct HD studio lenses.
The XJ23x7BIE-D utilized the best of contemporary computer-aided design techniques and breakthrough optical technologies to achieve a superbly performing HDTV lens – having only modest performance trade-offs compared to the top of the line XJ25xs studio lens – with these design innovations enabling lower costs.
ABOUT THIS LENS
The XJ23x7BIE-D allied the most state of the art in Canon optical developments with resourceful engineering design strategies. The design optimization achieved an excellent MTF profile over the image plane — that closely matches that of the flagship XJ25xs HD studio lens in the central image region with only a modest compromise in the outer extremities. A high MTF is maintained over the total focal range – with the very best characteristics centered on the medium to short focal lengths (where wide-angle imagery inherently contains greater detail).
As with all of Canon’s studio lenses the simultaneous optimization of MTF and contrast range – that contributes to excellent subjective picture sharpness – also constituted a pivotal optical design strategy for the XJ23xs. Preservation of a high MTF over the critical mid-band 20 – 75 Lp/mm spatial frequencies that is important to perceived picture sharpness remained a core design imperative. The contrast range 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. Uniformity of brightness across the image plane was also carefully controlled which further serves to enhance overall picture clarity.
Finally, the critically important requirement of low geometric distortion at wide-angle settings constituted another central design imperative and was effectively resolved by Canon’s advanced three-group internal focusing system (which also minimizes alterations of chromatic aberrations during the focusing action).