NiSi Cine Lens Athena Prime 35mm T1.9 RF-Mount

NiSi Cine Lens Athena Prime 35mm T1.9 RF-Mount – Fast T1.9 aperture for soft bokeh and full-frame coverage

What this lens offers

The NiSi Athena Prime 35mm T1.9 in RF-mount delivers a fast T1.9 aperture for shallow depth of field and softer background separation. It is part of the Athena Prime series, a matched set that spans ultra-wide to portrait focal lengths. Use this lens when you need a compact prime with a wide maximum aperture and compatibility with full-frame and large-format sensors.

Key features

• Fast T-stop: the 35mm version has a maximum aperture of T1.9, allowing for controlled exposure and pleasing bokeh.
• Series coverage: the Athena Prime family ranges from 14mm (ultra-wide) to 135mm (portrait), covering a wide variety of shooting scenarios and subject types.
• Image circle: 46mm image circle, making these lenses suitable for full-frame and large-format sensors.
• Mount options: available across the series in ARRI PL, Canon RF, Sony E, Panasonic/Leica L and Fuji G mounts.
• Drop-In / rear filter system: the series includes a proprietary rear filtration system with Drop-In filter options for RF, L and G mounts; E-mount is available in versions with and without Drop-In filter; PL-mount uses a rear filter.
• Infinity focus requirement: use the Drop-In clear filter on RF, L, G and E mounts, and the rear filter on PL-mount, to achieve infinity focus and clear images.
• Compatibility note: Sony FX9 cameras cannot use the E-mount version with Drop-In filters.
• Weather protection: NiSi provides weather sealing for the Drop-In filter.
• Consistent handling: lenses in the series are similar in weight so they do not require gimbal rebalancing when switching between Athena lenses.
• Filter thread: all lenses except the 14mm share a 77mm front filter thread.
• Matched controls: aperture and focus rings are matched across the range for consistent operation.
• Focus performance: 300° focus rotation and fluorescent focus scales in both imperial and metric units for precise focus pulls.
• Mechanics: standard 0.8 mod focus and iris gears for compatibility with common follow focus and matte box systems.
• Optical control: the series offers ultra-low chromatic aberration and micro-contrast control for finer image detail.
• Close-up option: a NiSi 77mm close-up lens (sold separately) can reduce minimum focus distance to create macro effects.
• Focus breathing: lenses have been designed to minimize focus breathing so field-of-view change during focus pulls is very small.

Performance and common uses

The 35mm T1.9 is well suited for interviews, environmental portraits and narrative work where moderate wide-angle perspective and controlled background separation matter. Because the Athena series provides matched weights, gears and ring positions, you can switch lenses quickly during a shoot without reconfiguring follow focus or rebalancing a gimbal. In addition, the large image circle and low chromatic aberration make the lens applicable for projects using full-frame or large-format sensors.

Compatibility notes and practical tips

When using RF, L, G or E-mount versions with a Drop-In filter, install the Drop-In clear filter to achieve infinity focus and clear images. For PL-mount lenses, use the supplied rear filter in the same way. Keep in mind that the Sony FX9 cannot use the E-mount with Drop-In filters, so choose the appropriate mount/version for that camera.

Because the lenses are weight-matched and share gear positions, you can change focal lengths quickly on set without rebalancing stabilizers or adjusting follow focus setups. The 300° focus rotation and fluorescent scales make precise focus pulls easier during narrative and documentary shoots.

FAQ

Question: Is the 35mm Athena Prime suitable for full-frame cameras?
Answer: Yes. The Athena series has a 46mm image circle, which covers full-frame and large-format sensors, so the 35mm RF-mount will work on those systems.

Question: Do I need to use a Drop-In filter to focus to infinity?
Answer: Yes. For RF, L, G and E-mount Drop-In versions, you must use the Drop-In clear filter. For PL-mount lenses, use the rear filter. Without the correct filter in place you may not achieve infinity focus or optimal image clarity.

Question: Can I swap Athena lenses on a gimbal without rebalancing?
Answer: The Athena primes are similar in weight and share gear positions, so switching lenses in the series typically does not require rebalancing on a gimbal.

Question: Are there versions of the lenses without the Drop-In filter?
Answer: Yes. The E-mount is available in two versions—one with the Drop-In filter and one without. RF, L and G mounts include the Drop-In option, while PL uses a rear filter.

Question: How do these lenses handle focus pulls and focus breathing?
Answer: The lenses offer 300° focus rotation and fluorescent scales for accurate marks and precise pulls. The Athena primes are also designed to minimize focus breathing, so field-of-view change during focus adjustments is kept very small.