Conversion Zooms For S16
Published : 11th July 2004
Can anyone tell me about the new conversion lenses available in PL mount that are basically video camera zooms that have been converted for use in S16mm?
Experience. Specific brands, focal lengths. Sharpness compared to Canon and Ziess zooms?
Optex has been offering these for years, available in the US from ZGC.
also has conversions. There's two schools for these conversions,
the simple relay adapter lenses that change the mount, magnify the
image a bit to extend the focal length so that it covers the S-16
frame and correct for the multiplane focusing of the colors (forget
the name for that) to the flat field for film (say that five times
quickly). The other is a complete overhaul and rehousing of the
optics to transform them into dedicated cine lenses. The advantage
of the simple converters such as the Abekas system from Optex (forget
what Century calls theirs) is that the lens can still be used for
video and in film use you can still use the zoom control motor on
the lens with a simple adapter cable, plus it is a much cheaper
way to go. But I question the optical quality, as this is forcing
the light to jump through some additional optical hoops.
On the other hand, the rehoused lenses are excellent in both optical performance and physical robustness. Optex converts a couple of Canon zooms to a 10.3-216 (20x) and a massive 14.5-480 (33x). They used to make a 7-63 until Canon came out with their own. Century uses Fujinon glass to make an 11.5-215 (19x) that sells brand new for a paltry $10,000--fantastic deal. All of these lenses offer great optical quality. Remember that the beloved Canon zooms have all been reworked versions of their video lenses. I was extremely impressed with the quality of the shorter Optex/Canon and the Century/Fuji when I first checked them out at trade shows, and that opinion was confirmed with later tests and practical experience. The lenses do breathe some, but this is to be expected with 19x & 20x zooms. The colors, contrast, corner sharpness, flare resistance, chromatic aberration, and barrelling all performed well. Although such long range lenses aren't quite as sharp as a modern prime, I'd say you could confidently intercut them (especially in video). The Century/Fuji isn't quite as cold as the Optex/Canon, which means that the Optex probably is closer to the look of Zeiss primes, but again I wouldn't have an issue intercutting them all.
In regards to the use of converters for video zoom lenses on S16.
I have been shooting a feature using a Canon 8-64 (designed for S16) as the primary lens and a Canon video zoom, 17X7.7 BIRS, with an Abekas adapter, for S16, for longer lens use. I have seen shots, of the same scene intercut between these two lenses and there seems to be little noticeable difference in color or sharpness. There also does not seem to be much loss, if any, of light transmission through the adapter. Since I only use the video zoom for longer focal length shots it seems to me to be a good mix of lens characteristics.
It is certainly very convenient to have the ability to use the power zoom if necessary. And, since I also regularly shoot video with my BVW 300A BetaCam, I can simply remove the adapter and change the back focus of the lens for the video camera.
adapter is available for about $3000 from Les Zellan at ZVC.