Table of Contents
perspective control, shift and/or tilt lenses
- see also:
- links to other websites:
- info on tilt shift and the Scheimpflug principle here and explanatory pic here and the Hinge rule here
- a great explanation on hinge rule & Scheimpflug principle here:
- http://www.cambridgeincolour.com/tutorials/tilt-shift-lenses1.htm - using them for shift including calculator
- http://www.cambridgeincolour.com/tutorials/tilt-shift-lenses2.htm - using them for tilt including calculator
- Canon TSE tilt shift lenses:
- portrait examples:
- tilt-shift lens vs Lightroom Keystone correction in post-processing
-
- tilt shift lens is far better if you are doing panoramic stitches (unless perhaps if you resort to using a nodal point tripod head)
- keystone post-processing may work for a simple image, but you will need to crop and you thus lose pixels - you can partly address this by using a wider angle lens
-
introduction:
- whilst perspective control using shift lenses to correct converging lines can be largely done in post-processing in tools such as Photoshop, the ability to change the plane of focus by using a tilt lens cannot be achieved satisfactorily in PS.
- a tilt lens can be very useful for product photography as well as macrophotography or even portraiture but accurate focus of the distorted focal plane ideally requires use of Live Preview such as in the Canon 1D MarkIII.
- some medium format film camera systems (eg. Fuji GX680III, Linhof 679 view, Horseman VR)and practically all large format cameras have tilt and shift capability via use of bellows.
- changing the plane of focus using tilt lenses:
- the amount and direction of the tilt determines where the Hinge line is.
- any movement of the camera back towards or away from the lens (eg. by changing focus ring) causes the plane of sharp focus to rotate about the Hinge Line.
- the plane of focus is formed by a line passing through 2 points:
- a fixed point (Hinge line) for a given degree of rotation & tilt of the lens located directly below the lens at the intersection of 2 lines:
- a line parallel to the film plane at the level of the lens
- a line parallel to the lens tilt which lies 1 focal length in front of the lens
- to determine which tilt angle to use based on the vertical distance (J in feet) from the lens which this point is placed can be determined by the equation:
- tilt angle = arcsin(focal length/J)
- if focal length in mm and J in feet this approximates to tilt angle = f/5J.
- eg. if using TSE90mm lens with 8mm tilt, this point is ~2.25 feet from lens (4.5 feet if 4mm tilt)
- a moving point (Scheimpflug line) along the lens plane which intersects with a line parallel to and intersecting with the film plane
- perspective control using a shift lens:
- to determine how far from a subject you need to be to avoid convergence, use the following equation:
- subject distance = actual focal length in mm / (height above centre of film in mm x target height)
- on a full frame sensor with 11mm shift:
- landscape: height above centre of film = 23mm
- portrait: height above centre of film = 29mm
- thus with 90mm lens, subject distance must be more than 3.1x the subject height
- on a APS-H sensor (eg. Canon 1D series) with 11mm shift:
- landscape: height above centre of film = 20mm
- portrait: height above centre of film = 25mm
- thus with 90mm lens, subject distance must be more than 3.6x the subject height
- a teleconverter multiplies both the focal length and the amount of shift.
- hope I got all this right.
- NB. at the extremes of shift, vignetting effect will occur as angle of light to film plane becomes more acute.
- perspective control in Photoshop:
- via Filter:
- Filters:Lens Distortion then adjust vertical & horizontal perspective distortion
- via Transform:
- Select:All then Edit:Transform:Perspective then adjust the handles to correct the distortion
- in either case, this will result in a converging edge to your image which will then require cropping to get back to a rectangular format, thus there is a cost in potentially detail but also in loss of pixels due to cropping.
- pseudo-tilt effect in PS:
- PS cannot replicate the optical characteristics of tilt effect but you can apply selective blur:
- perspective control using the LensBaby tilt/shift lens:
- these lenses are fairly cheap and can be fitted to most dSLRs to primarily provide creative images rather than technically perfect commercial images as with most other perspective control lenses.
- these lenses are NOT true perspective control lenses but just provide a central sharp area with surrounding blur, and the location of this central sharp area can be moved around the frame although it becomes less sharp the further it is moved from the centre - and at its best, its not that sharp.
- unfortunately to change aperture you must physically replace the aperture stop
- in most cameras, aperture-priority metering works but in some Nikons you must use manual metering.
- $US270 for current 3G version & only weighs 162g.
- 50mm focal length;
- minimum focus 30cm;
- aperture stops f/2 through to f/22.
- see http://www.dimagemaker.com/article.php?articleID=979 and http://www.dimagemaker.com/lensbaby-photography/lensbaby.php - tests to demonstrate use at different apertures and for infrared use.
- but you can achieve similar results in Photoshop using radial blur, etc, this lens saves you time on the computer but at a cost of less versatility in changing the end result.
Micro Four Thirds:
- fortunately with MFT cameras you can buy tilt or shift adapters which allow you to convert almost any lens designed for 35mm to a tilt or shift lens and you get HD video - and if using an Olympus body, it will be image stabilised - just awesome!!
- you can use Canon EF tilt shift lenses via EF adapter but you must change aperture with lens on a Canon body unless you use an adapter which allows aperture control
- you can use Nikon PC or Olympus OM shift lenses via adapter as with Four Thirds cameras
Canon dSLR options:
Nikon dSLR options:
- Nikon F mount perspective control lenses:
- PC Nikkor 19mm F4E ED
- announced Oct 2016
- 97° of coverage and can shift ±12mm and tilt ±7.5°
- unlike existing PC-E designs, the mechanism for tilt can be rotated independently from the mechanism for shift, allowing the tilt to be set either parallel to or perpendicular to the shift and aperture is electronically controlled
- NOT compatible with all dSLRs:
- “When used with cameras other than the D5, D4 series, D3 series, D810 series, D500, or Df, some combinations of shift and rotation may not be possible due to the fact that the lens comes into contact with the camera body”
- three ED and two aspherical elements
- $US3400
- PC-E Nikkor 24mm f/3.5D ED:
- introduced early 2008
- 11.5mm shift plus 8.5deg tilt plus 90deg rotation
- auto aperture control with newest Nikon dSLR's compatible with electromagnetic diaphragm (eg. D300/D3)
- manual aperture control ring and stop down button
- close focus 0.21m giving 1:2.7 macro
- 3 ED glass; nano coating; 9-blade diaphragm; 77mm filter;
- PC-E Micro 45mm f/2.8D ED tilt-shift macro lens (late 2008):
- automatic aperture plus manual over-ride aperture ring
- 0.5x macro at 0.253m close focus; nano coating; 9-blade diaphragm;
- dust and moisture resistant; 77mm filter;
- PC-E Micro 85mm f/2.8D tilt-shift macro lens (late 2008):
- automatic aperture plus manual over-ride aperture ring
- 0.5x macro at 0.39m close focus; nano coating; 9-blade diaphragm;
- dust and moisture resistant ; 77mm filter;
- PC Micro-Nikkor 85mm f/2.8D:
- tilt-shift macro lens which can focus to 3.9cm for 1:2 macro. Can stop down to f/45.
- manual aperture stop down button; 77mm filter; 775g;
- introduced in 1999;
- Hartblei Super Rotators and other Schneider-Kreuznach tilt-shift lenses
- see under Canon above
- what about the older PC lenses - no longer listed on Nikon's site:
- manual preset apertures and no tilt, thus not so good for macro.
- these tend to have a lot of CA and edge softness on dSLRs
- PC Nikkor 28mm f/4 shift
- introduced in 1975, discontinued in 1983 and older ones are NOT compatible with Nikon dSLRs.
- PC Nikkor 28mm f/4 with serial numbers of 180900 or earlier must not be used with Nikon dSLRs as they may cause damage.
- PC Nikkor 28mm f/3.5 shift:
- introduced in 1980
- improved field curvature & reduction in coma & chromatic aberration from the f/4 version
- The Nikons handle better than the Canon TS due to the fact that they only shift in one direction. It is easy to re-center them, meter and then shifted again to compose. With the Canons, it is hard to tell when the lens is centered unless you are looking at the scale and thus using them handheld is more difficult. This applies to many of the other shifting lenses as well.
- close focus to 0.3m;
- PC Nikkor 35mm f/3.5 shift:
- introduced in 1975
- PC Nikkor 35mm f/2.8 shift
- introduced in 1978, revamped in 1980 with 7 elements in 7 groups to improve light fall off and aberrations (appears they had serial numbers from 179091 onwards)
- 11mm shift plus 360deg rotation but no tilt
- medium format & large format bellows system attachments (see above for Canon)
Olympus dSLR options:
- can use any as listed under Canon except Cambo/Horseman solutions or Canon EF lenses but 2x crop may be an issue.
- be aware though that the flash housing on some Olympus dSLRs may get in the way of the knobs on some of these lenses.