Canon's tilt-shift lenses are well known for being versatile and very sharp, useful for a huge range of applications, from avoiding converging parallels in architecture and real estate photography to controlling your depth of field independent of the aperture. This great video review takes a look at the widest in the lineup, the TS-E 17mm f/4L.
Coming to you from Christopher Frost, this excellent video review takes a look at the Canon TS-E 17mm f/4L Tilt-Shift lens. This lens debuted in 2009, and in the meantime, sensor resolutions have skyrocketed, putting more demands on it, but at the same time, tilt-shift lenses are generally among the sharpest out there and tend to stand the test of time better than most. The TS-E 17mm f/4L offers a range of features, most importantly, +/- 12mm of shift and +/- 6.5° of tilt (both can be applied independently), along with +/- 90° of rotation. Along with those, it has four Ultra-Low Dispersion elements for reduced chromatic aberrations, Sub Wavelength Coating for reduced flares and ghosting and increased contrast, an aspherical element for increased sharpness, and a rounded eight-blade diaphragm for smoother bokeh. Check out the video above for Frost's full thoughts on the lens.
Love Christopher Frost's reviews. They are in-depth and un-biased.
One caveat about using the shift function for panoramas. (I have the 24mm TS-E not the 17mm). He mentions keeping your exposure the same throughout the series of images (Manual mode) but in practice the Shift function will darken the exposure up to a full stop depending on the amount of Shift. I've had more luck using Aperture mode which compensates for this, keeping all my images in the same range.
Photoshop/Lightroom will have an easier job of making a pano if the final explores are similar.
There are no tilt-shift lenses that are competently made, None tilt and keep the same distance from the centre of the frame consistent, which would allow the use of central spot autofocus, instead, all need refocused after any change in tilt. Please someone get the tilt radius correct!