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Extended lens alternatives for the ALPA 12 FPS and ALPA Silex with the upgraded range of Canon EF TS-E lenses.
Tilt and Shift are still special applications in the "35mm" range. Canon's TS-E lenses are designed for this task with the ability to perform tilt and Shift in some combinations. Only the extreme wide-angle lenses TS-E 17/4.0L and TS-E 24/3.5L (now Mark II) were available as professional L-optics. Expected for quite some time, Canon now offers a new 50, 90, and 135 mm lens with the red ring as exclusive lenses.
The usable image circles of these lenses have a minimum of 65/70 mm. Since the introduction of ALPA 12 FPS (2012), ALPA has supported the Canon protocol concerning these unique lenses. As a result, ALPA FPS customers used such combinations of Canon TS-E lenses and any digital back since the FPS introduction in 2012.
Due to the introduction of the "electronic shutter" for various digital backs (Phase One IQ3 100, Hasselblad H6D-100c, Sinar S30|45, etc.), these lenses can now show their abilities on any classic ALPA plus ALPA Silex control unit.
The line-up has become very grown-up with 17, 24, 50, 90, 135 mm. In December, Canon Switzerland kindly provided us with their first demo lenses. We have used the new optics on an ALPA with 100MP digital back in a full adjustment of 12 mm left/right to demonstrate the possibilities and limits. The result was a stitched panorama of 16,500 pixels native length in Photoshop, merged from the single files.
The sample images can be viewed via Zoomify or downloaded in full resolution as JPG and PDF. All details, including the sensor format and various image circles, have been plotted on it. These are demo lenses from Canon Switzerland and therefore not explicitly selected.
Canon lenses are very well manufactured and feature an excellent imaging performance. Particularly noteworthy is the astonishingly low sensitivity to scattered light. All lenses work on the ALPA 12 FPS with Lens Module CAN or on each ALPA 12 with Lens Module and ALPA 12 Silex control unit.
Due to the prevailing weather conditions, we had to carry out the short test indoor in a suitable building. The St. Anton catholic church is located around the corner and is ideally suited for this purpose. Here a picture with the Canon TS-E 90/2.8L and Phase One IQ3 100 at 12 mm rise.
The following three pictures show the horizontal stitches with the corresponding lenses. The photographs can be explored as Zoomify images (not compatible with all browsers) or loaded as JPG and PDF in full resolution.
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Canon TS-E 50/2.8L - Zoomify (not compatible with all browsers)
Results as full res JPG and PDF
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Canon TS-E 90/2.8L - Zoomify (not compatible with all browsers)
Results as full res JPG and PDF
Links
Canon TS-E 135/4L - Zoomify (not compatible with all browsers)
Results as full res JPG and PDF
Due to the construction, the front element is shifted during the adjustment. Without compensation of the displaced entrance pupil, a possible stereoscopic error may remain. However, this is likely to be relatively unobtrusive at longer focal lengths. The stitching process, including any parallax correction, was fully automated in Photoshop CC and the results appear to be appealing. The 135 mm lens proved to be demanding as some experimenting was necessary to make it fit.
As the images show, a particular movement beyond the intended image circle is possible. During shifting, however, unintentional mechanical vignetting may occur as a result of the lens construction. This darkening of the corners is due to the low rear lens group, which vignettes especially at longer focal lengths on the own tube. Nevertheless, three shots (middle unadjusted, left, right) allow panoramas with a virtual sensor of 40 x 76 mm and around 16,500 x 8,600 pixels or 142 MP to be realized.
The ALPA photographic platform proved to be even on the smallest camera, the ALPA 12 TC, more than capable of combining a 100 MP digital back and tilt/shift lenses from Canon. Fortunately, Canon went the road of a large diameter mount right in the beginning. This additional freedom resulted in much more flexible use of such lenses as the Nikon lenses with their relatively small lens mount diameter.
The only caveat in general: Unfortunately, however, we had to observe a certain degree of variation in optical performance between samples of the same type of lens in the past. This observation was also confirmed to us by customers. Such variation was the case at least with the 17 mm and the 24 mm lens in the past and may not apply for future production.
Addendum A, 2020: Many architectural photographers use the Canon TS-E lenses on an adjustable ALPA. Instead of shifting the lens, it remains in the zero position. The photographer realizes the Shift left/right or up/down with the ALPA's back card, thus avoiding unwanted stereoscopic effects.
Addendum B, 2020: ALPA has introduced an additional manual Canon lens adapter this year. This purely mechanical interface does not allow dynamic adjustment of the aperture. However, many Canon photographers know the trick: stop down the lens on a Canon body to f/8 (or as desired) and remove it while holding down the stop-down button. The aperture of the lens remains at the selected value.
