Kern Vario Switar 12.5-100mm

The Kern Vario Switar 12.5-100mm f/2 is a parfocal Swiss cine zoom from the 1960s, built for the Paillard Bolex H16 family. With an 8x focal length range (12.5mm to 100mm) at a constant f/2 aperture, it was the premium zoom of its time—and is in demand again today, with the 16mm film revival.

Parfocal — What That Means

Parfocal means: focus is maintained while zooming. No refocusing is needed when zooming in. This sounds like a given, but it's not—many photo zooms lose focus when changing focal length. Cine zooms are parfocal because the 1st AC doesn't have to constantly adjust focus on set.

Aperture

f/2 across the entire range is still remarkable today. Modern photo zooms only achieve this at the lower end of the focal length. For 16mm available light production, the Vario Switar is therefore a candidate for a single-lens setup: one lens covers everything from wide establishing shots to telephoto close-ups.

Mount & Adaptation

The original mount is Bolex H16 (bayonet with rotating ring). PL adapters exist for modern cine use, but the typical use case remains: Bolex body + original lens. Adaptation to other bodies (ARRI SR, AATON) is possible but uncommon.

Grain Character

The Vario Switar is often associated with the characteristic Bolex grain—but grain comes from the film stock, not the lens. What the Vario Switar delivers: slightly soft mid-range sharpness, a subtle glow at wide open aperture, and bokeh without extreme swirling. Classic Swiss precision look.