Cine or movie camera lenses on Micro Four Thirds cameras

Written by Gary on July 18th, 2010

One of the main attractions of the Micro Four Thirds camera system is that you can use almost any lens ever made on it, so that your creativity and fun is maximised.

This is possible because the MFT system has a short sensor to lens mount distance which allows adapters to be made which will allow many cine lenses to focus to infinity, and the cropped sensor of the MFT system means many of these lenses will give reasonable coverage across the frame, although most will cause substantial vignetting – this problem is MUCH more pronounced on larger sensors such as the APS-C size Sony NEX camera system.

Cine lenses offer users of Micro Four Thirds an opportunity to experiment with very small lenses (perhaps a 1/4 of the size of 35mm format lenses) with wide apertures and short focal lengths at often very reasonable prices, and thus allow images with a different “look” without breaking your bank, or your back. The most popular focal lengths to use on Micro Four Thirds are 25-75mm.

Cine lenses are often very simple lenses and include newer Closed Circuit CCD TV lenses which are generally not designed for high image sharpness as with photographic lenses, but also include very expensive, high quality lenses such as PL prime lenses.

16mm movie film dimensions are 10.26mm x 7.49mm, while Super-16mm movie film is 12.52mm x 7.41mm – both MUCH smaller than Micro Four Thirds sensor size of 18mm x 13.5mm (hence the possible vignetting and peripheral smearing of details).

Lenses with a 22mm image circle will give full coverage on a 4:3 Micro Four Thirds image, while a 20mm image circle will cover a 16:9 cropped Micro Four Thirds image, and 16mm image circle (for Super 16) and 14mm image circle (for regular 16) will cause vignetting even on 16:9 cropped Micro Four Thirds.

In general, C mount lenses with focal length less than 25mm will generally have substantial vignetting, and the bokeh is often characterised by a circular, swirling appearance, for instance, this image taken with a Tokina 16mm TV lens and posted on the net by Ben Bammens:

Tokina 16mm

Longer focal length C mount lenses give more classical image appearance as in these images by Yu-Lin Chan:

The main mounts for cine lenses are:

  • D mount – 0.625″diameter thread, 12.29mm flange distance, designed for 8mm movie film – NOT useful for M43 cameras
  • CS mount – 1″diameter thread, 12.52mm flange distance, designed for 16mm movie film – NOT useful for M43 cameras
  • C mount – 1″ diameter thread, 17.5mm flange distance, designed for 16mm movie film
  • Arri PL mount – breech lock mount for 16mm and 35mm movie film
  • Panavision PV mount – breech lock mount for 16mm and 35mm movie film
  • Arri Maxi PL mount – mount for 70mm movie film

Issues with C mount to MFT mount adapters:

  • some lenses, especially TV lenses do not have aperture ring and thus you will not be able to stop them down
  • some lenses may require a little machining (eg. Sony TV 16/1.8)
  • Lenses with max. inner diameter of 37.2mm (lenses with max. near-thread diameter of 37.2mm all can fit well without any modification)
  • Lenses with near-thread diameter larger than 37.2mm but smaller than 49.2mm still can fit, but will not focus to infinity!

Examples of C mount lenses:

  • Kern-Paillard lenses for Bolex movie cameras
  • Schneider 10mm f/1.8
  • Kodak Cine Ektar 15/2.5 – vignetting
  • Schneider Kreuznach Xenon 16/1.9 – vignetting
  • Kern Switar 16/1.8 H16 RX – vignetting
  • Som Berthiot 20mm F1.9
  • Wollensak Cine Velostigmat 1:/1.9
  • Kodak Ektar 25mm f/1.4 – corner vignetting
  • Taylor & Hobson
  • SOM Berthiot 25mm f/0.95 gives full coverage but requires machining
  • Angenieux types M1 or M2 25mm f/0.95 give 95% coverage
  • Angenieux 75mm f2.5
  • a Micro Four Thirds compatibility table can be found here
  • a more extensive listing of C-mount lenses can be seen here

To get ideas of what you can achieve with these lenses, surf the net, for example:

 

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