Blog / Resources / Lenses Some S-35 zooms already cover FF (you just didn’t know this!) Lenses This is an extremely brief article to help to explain a lesser-known but extremely valuable tip. In summary, film zooms designed to cover S-35 sensors, will also cover Full Frame as well IF used with a 1.5x extender and this is built into several zoom lenses already, such as the Canon Cabrio zooms. In English, this means that you can use Full Frame cameras with existing PL zooms without needing external image expanders. Canon Cabrio S-35 zooms all include the built-in 1.5x extender facility, to extend the focal length by 1.5x by means of activating a 1.5x rocker knob and in doing so, cover Full Frame sensors. Sometimes, we need to hear things several times in order to fully appreciate how useful they are and so it is with the 1.5x lens extension function, which I realised recently not only ‘zooms-in’ by a factor of 1.5 but also necessarily increases the image size, enabling images to cover Full Frame sensors. The 2 x Canon Cabrio S-35 zooms below all include the built-in 1.5x extender facility, so that images can be both ‘zoomed-in’ and subsequently, also cover Full Frame simply by using the 1.5x rocker knob. Canon CN20x50 (50-1000mm, converts to 75-1500mm with built-in 1.5x extender)Canon CN10x25 (25-250mm, which converts to 37.5-375 with 1.5x extender) When used normally (without the 1.5x extender), S-35 zooms will vignette when used with a FF sensor. When the 1.5x extension is engaged, image focal lengths increases by a factor of 1.5 and will cover FF. You can of course use a PL lens extender to achieve this as well. VMI stock 2x converters which will both double the focal length and ensure that the resulting images cover Full Frame. IBE 2x PL converterMTF 2x PL converter When using lens extenders, sensitivity will reduce The laws of optics necessarily dictate that if you enlarge an image, then the brightness of the image will also reduced, so the camera operator must be made aware that if the 1.5x extender is used, then the maximum iris of the lens reduces by 1.5x as well. Some examples using built-in 1.5x converter: Canon CN10 lens: 25-187mm/T2.95 (to T3.95 at 250 mm) in S-35, becomes 37.5-375mm/T4.4 at 37.5 – 281 mm (to T5.9 at 375 mm) with 1.5x extender and covers FF.Canon CN20 lens: 50-560mm/T5 (to T8.9 at 1000 mm) in S-35, becomes 50-560mm/T7.5 (to T13.35 at 1500 mm) with 1.5x extender and covers FF.Canon CN7 lens: 17mm/T2.95 in S-35, would become a 25.5mm/T4.4 with 1.5x extender and covers FF, though this is not built into the lens. Some examples using external 2x PL converter: Angenieux Optimo 15-40/T2.8 in S-35, becomes 30mm-80/T5.6 with 2x extender and covers FF.Angenieux Optimo 45-120/T2.8 in S-35, becomes 90mm-240/T5.6 with 2x extender and covers FF.Angenieux Optimo 24-290/T2.8 in S-35, becomes 580mm-240/T5.6 with 2x extender and covers FF. Note that external 1.5x converters are also available to achieve lesser magnification and stop loss. Barry Bassett, March 2021Images of rocker and lens charts are courtesy of CVP Related articles VMI is Infinity’s Prime UK Rental House Lenses VMI has a long-standing relationship with Infinity Photo-Optical who makes the Infiniprobe TS160 probe lenses. Barry Bassett, VMI’s Managing Director, has been recognised as being their ‘Nelsonian Award’ winner back … Read more New generation of Auto Focus lenses now available with E and EF Mounts Lenses Auto Focus is here to stay and whilst this is not a panacea to force all focus-pullers to retrain, the increased adoption of Full Frame (which necessarily makes focussing more critical than S-35 or APSC formats) and the enhanced development of the technology, makes this functionality more useful and as a result, we are noticing an increased interest in it. What real world Cinematographers think about using Infiniprobe lenses Cinematography, Lenses The Digital Cinema Society presents an exploration of Micro/Macro cinematography with three DPs including Bill Bennett, ASC, James Mathers, and Cameron Cannon. The trio photograph a variety of shots in order to evaluate these exceptional lenses and also share their insights in behind-the-scenes coverage.