View Full Version : Century Optics 4:3 to 16:9 Anamorphic.


Bob Hart
April 22nd, 2013, 01:12 PM
Given that there are now a few S16 sensored cameras around now, for those who might have an interest, I offered up a Century Optics anamorphic adaptor to two lens sets for the SI2K,

Cinema Products Ultra T* 9mm, 12.5mm, 16mm, 25mm and
Optar ( Lumatech ) Illumina, 12mm, 16mm, 25mm 50mm.

This anamorphic lens I have, was desgned as a zoom-though front attachment for the 1/3" sensor Sony DSR PD150 and I think it may have fitted the contemporary Canon MiniDV lens-in-camera model which bore a similar lens system.

On the CP lenses, as closely coupled as can be, it seems to work on all including the 9mm. I need to do some furthur looking at it on the 9mm as there may be some edge brightness falloff at tighter apertures.

The field of view is widened such that as example, the 16mm view is widened to that approximately of the 12.5mm.

The sharpness readings were reduced by only 5 points on the wide lenses with the anamorphic on front which surprised me. On the 25mm, the picture is less pretty as more sharpness is lost. The longer lenses may require recollimation to achieve infinity focus with the adaptor on front.

In conversion from the native 16:9 of the SI2K to near cinemascope, there might be a notional gain of apparent vertical sharpness to offset the softening of the horizontal stretch. This was the rationale for the adaptors as 16:9 was otherwise achieved on the PD150 by cropping the top and bottom of frame at the cost of vertical resolution.

In the real world of theatrically projecting via anamorphic lenses, the 16:9 to cinemascope arrangement does not conform to any existing standard so far as I know. The image would have to be furthur laterally shrunk to rescale to the 4:3 frame of the cinemascope image for theatrical projection.

I would not be confident there would be any advantage remaining by the time all that rescaling and pixel stretching was done with.

The Illumina lenses do not fare so well. Because of their design in which the lens front elements are deeply recessed, a close clouple of the 16:9 adaptor is not possible. Therefore the usable lenses start at 16mm where there remains a slight edge vignette, the 25mm performs similarly to the CP 25mm. The 50mm image yield through the 15:9 adaptor is observably softer.