Rise. Tilt To Your Audience. Shift Sideways. Click Your Shutter.
Those of you old enough to have wrinkles that won't go away may have had a chance to use a view camera or a tilt/shift lens in the past. You know the dance, and when to dance it.
For the newbies - you do the dance when you want undistorted verticals in an architecture shot - or when you want easy stitching for a panorama - or want infinite depth of field for a product or landscape shoot at wide aperture. The Scheimpflug Principle takes care of the last named and the rising front of the camera - or falling back, for that matter - takes care of the first. The shift lets the budding panoramacist add more width to what they do and the stitching programs love the result.
While you can get massive movements on a 4 x 5 or 8 x 10 sheet-film monorail camera, you are a little more restricted with the dedicated tilt/shift lenses that the major DSLR makers provide. Nevertheless there are movements there and you can still dance.
Unfortunately right now there are very little options for we dedicated mirror-less system camera users - only a few limited sorts of adapters that produce a little movement, and no dedicated lenses from the actual makers. We can only hope that the lens designers for our respective brand choices will think to add something of this nature for the lens road maps.
Until then there are a number of us experimenting with tilt/shift movements on our old 4 x 5 cameras by attaching mirror-less bodies to the rear standard and as wide an angle lens as we can find for the front. It's a situation that really wants bag bellows and even then there are compromises in what we see on the LCD screen. One thing - a least most 4 x 5 wide angle lenses have a massive coverage foot print and on a APS-C sensor you don't run out of image as you move.