Paul M Clements

Some of the finest still lenses compare favourably to their Cine lens counterparts and for years companies such as Panavision, ARRI, Samcine, Century Optics and many others have been rehousing still lenses for use in cinema production. Furthermore films as recent as The Bourne Ultimatum have been shot using modified Nikkor lenses (View Article at International Cinematographers Guild). With care and attention to the choice of lens and it’s quality, still lenses can be used productively in a cine environment and get exceptional results.

Common problems do however exist. Firstly, the focus throw on still lenses is smaller than that of cine lenses. When attaching a follow focus to the lens it would require gearing in order to give the focus puller more movement in the focus knob compared to the movement of the focus on the lens. The focus barrel on still lenses more than often rotates in the wrong direction and focus marks are less accurate than on cine lenses.

Another common problem is controlling the aperture. Many still lenses control it via the body of the camera and subsequently have no physical control on the lens itself.

Cine and still lenses have different types of mounts. PL being one of the most commonly adopted cine mounts and Nikon F-Mount and Canon EF-Mount representing two of the most recognised still mounts. Usually these lenses need a complete overhaul and rehousing in order to correctly position the lens to the film plain or sensor of the camera. This is because the flange focal distance in still lenses is smaller than cine lenses and therefore a PL mount conversion cannot simply be added.

Generally speaking still lenses are usually not accurate enough for motion picture work even though they may be optically sound.

In order to combat the inherent problems special mounts for the RedOne, designed and manufactured by Birger Engineering Inc. Boston – Massachusetts, allow for the use of still lenses fitted with either Canon EF, Sigma SA, FourThirds (Olympus/Kodak/Leica & Others) or Nikon F mounts.

By coupling with the lenses automatic controls (Normally used by the corresponding DSLR camera bodies) the mounts can access the motors that control the lenses focus and aperture functions.

A focus puller can control the attached lens using a standard follow focus wheel (Prototype pictured above). By avoiding contact with the focus and aperture controls on the lens itself much of the perils of handling still lenses in a cine environment are removed.

The focus and aperture of a lens can also be controlled remotely, making it ideal for steadicam, handheld or crane work for example.

A further intended advantage of the mount is the lens data information can be converted from it’s native language to Cooke Optics’s /i or Broadcast, which will eventually be included in the camera. This would give the focus puller and post production live accurate data to work from.

Because there is no follow focus on a rig using such a mount, lenses can be swapped out quicker, allowing for greater efficiency on a shoot.

Breathing can be an issue in some still lenses (Although not all Cine lenses can lay claim to being free of it, especially older ones). But given the resolution in any frame shot on the RedOne a relatively simple animated mask can be applied in post to remove any breathing judged to be unsightly. There is also talk of a geared motor being used in conjunction with zoom lenses that will remove any breathing by adjusting the zoom slightly. The motor and the mount would be mapped to the specific lens so that as it is focussed the zoom would also be altered to counter the lenses natural breathing.

The mounts have yet to undergo real world testing so whether still lenses, used in conjunction with the Birger Mounts, are capable enough for use in demanding productions remains to be seen.

There have always been reasons for choosing cine over still lenses and for the large part reliability in the optics we know and trust will, and should, continue. Technology such as Birger’s mounts and the RedOne Digital Cinema Camera could however allow us to select from a wider range of lenses whilst lessening the traditional compromises and expense of rehousing them.