see also:

• http://www.canon.com.au/en-AU/Pro-Photography/Pro-Lenses/TS-E%2045mm%20f2_8
• perspective control, shift and/or tilt lenses
• Canon TS-E 90mm f/2.8 tilt shift lens
• Canon TS-E 24mm f/3.5L tilt shift lens
• Canon TS-E 17mm f/4L tilt shift lens

• 2011 prices suggest $A1999 new online
• minimum focus 40cm giving 0.16x magnification
• 10 elements in 9 groups floating optical system, and rear focusing mechanism
• 8 blade diaphragm
• 72mm filter thread
• manual focus
• up to 8deg tilt, 11mm shift and 90deg rotation
• Super Spectra coatings for accurate colour balance and enhanced contrast
• 645g, 90mm long by 81mm diameter
• introduced April 1991
• many reverse the factory default lens tilt-shift orientation otherwise the tilt tends to counteract the shift but this causes some vignetting on full frame
  • The lenses come preset from the factory with the axes opposite each other, but a Canon service center can adjust them so that they are on the same axis. This way you can use Scheimflug and a rising front (for example) at the same time.
  • see http://www.northlight-images.co.uk/article_pages/modify_canon_tilt-shift.html
• my 1D TiltShift

• at 45mm, it is more of an environmental portraiture use, but can be a more traditional 90mm portrait lens when used on a 2x crop camera such as Micro Four Thirds system
• tilt can be used to create selective focus

• tilt mechanism allows selective focus to create emphasis

• the tilt mechanism enables one to get all the scene in focus without resorting to extremely small apertures

• shift mechanism allows perspective control, although the 45mm focal length will be too long for many subjects

• place the camera on a tripod and use the shift mechanism to take 3 separate images which can then be stitched to create a panorama

• derived from http://www.cambridgeincolour.com/tutorials/tilt-shift-lenses2.htm
• J point is the distance below the camera that will be in focus (although this point will not be in the field of view of the lens)
  • J = lens focal length / sin(tilt angle)
• for landscapes, where nearly everything is in focus one usually selects a tilt and focus distance that changes the focus plane to horizontal (ie. 90deg) with the camera still aimed horizontally but placed at the J point above the ground.
  • thus determine how far you want to be from the ground (based on tripod, perspective, etc), then determine from the tables what tilt you will need and the focus distance to achieve close to 90deg focus plane.
• camera sensor size and aperture have NO effect on the angle of the focus plane BUT do alter the total angular depth of field, and thus the calculations should apply whether you use it on a full frame dSLR or a 2x crop Micro Four Thirds system
• at closest focus of 0.4m, you can change the plane of focus to max. 54 deg from horizon (or 36deg from perpendicular to camera), thus if you angle you camera down on your flat subject at an angle of 36deg with an 8deg lens tilt, your flat subject should be in focus (without tilt, your camera sensor has to be at parallel to the flat surface)

see more examples:

• some of my tilt-shift photos on Flickr
• PBase photo examples