I just received my new Canon 24mm TS-E f/3.5 lens, after many years of hard work I'm now retiring my old one! The new one comes with a superb optical quality, totally redesigned, been the first lens (together with the 17mm TS-E) to have an independent rotation of the tilt and shift axes relative to the camera and to each other!
Previously the tilt axis was set as standard at 90º to the shift axis, and the lenses could be modified to set them both in the same axis if the user desired. This restriction has now been discarded, making the lens movements, and therefore creative options, much more flexible. The tilt and shift mechanism rotates +/-90°, allowing shift in any direction, and in addition the tilt mechanism independently rotates +/-90°, allowing tilt in any direction relative to the shift. This functionality enables me to maximize depth of field in their images without stopping down as far as they would otherwise need - essential when wishing to squeeze every last pixel of detail from the latest 20+ Mp DSLRs while avoiding the deleterious effects of diffraction.
Canon has also gone to town on the the optical designs, including the use of high-precision aspherical front elements to keep distortion to a minimum, and multiple UD elements to reduce chromatic aberration. In the case of the TSE 24mm F3.5 L II, this means a considerably more complex formula than its predecessor - 16 elements in 11 groups, as compared to the 11 elements in 9 groups of the older design. According to Canon, the usable image circle is also much larger - 67.2mm as opposed to 58.6mm - which in principle allows a greater range of movements without vignetting. The lens also utilizes the company's new 'Sub-Wavelength Structure Coating', which is designed to reduce flare and ghosting dramatically in lenses that contain large curve-radius elements - most notably wideangles. Also included is the currently-fashionable circular aperture diaphragm, designed to give an appealing rendition to out-of-focus regions of the image.
Well, I can't wait to put this amazing lens in the field! You shall see the results soon!