NiSi Cine Lens Athena Prime 40mm T1.9 E-Mount

NiSi Cine Lens Athena Prime 40mm T1.9 E-Mount – Fast T1.9 aperture for controlled depth of field

The NiSi Athena Prime 40mm T1.9 in E-Mount delivers the specific optical qualities filmmakers expect from the Athena series. It shares the series’ design philosophy: consistent operation across the range, strong optical control, and practical features that suit professional cinematography and video production workflows.

Key optical characteristics

This 40mm Athena Prime offers a maximum aperture of T1.9, enabling shallow depth of field and pleasing background separation for portrait and narrative work. The Athena series uses T-stop ratings to indicate true light transmission, and the 40mm model conforms to that standard for consistent exposure across lenses in the series.

The series provides an image circle of 46mm, which makes the lenses suitable for full-frame and large-format sensors. The Athena optics emphasize ultra-low chromatic aberration and micro-contrast control to preserve finer image details.

Focus performance and control

The Athena Prime lenses are designed to minimize focus breathing. In practice, this means the change in field of view when you pull focus from minimum focus distance to infinity is extremely small, allowing smoother focus transitions in motion shots.

The 40mm lens shares a 300° focus rotation, which supports precise focus pulls. It also features fluorescent focus scales in both imperial and metric units for clear reference in varied lighting conditions and rig setups. Both the focus and aperture rings are matched to the rest of the Athena range for consistent hand and follow-focus operation.

Mounts, filters and rear filtration system

The Athena Prime line is available in multiple mounts across the series: ARRI PL, Canon RF, Sony E, Panasonic/Leica L, and Fuji G. For filter flexibility, the series incorporates a proprietary rear filtration system.

• RF, L and G mounts offer a Drop-In filter option.
• The E-Mount is available in two versions: with Drop-In filter and without Drop-In filter.
• PL-mount lenses utilize a rear filter.

Important operational notes:

• Sony FX9 cameras cannot use the E-Mount version that includes Drop-In filters.
• To achieve infinity focus and obtain clear images, you must use the Drop-In clear filter on RF-, L-, G- and E-mount versions that support it, and the rear filter on PL-mount versions.

NiSi also provides weather sealing for the Drop-In filter to increase reliability in challenging shooting conditions.

Handling, rigging and accessories

All Athena Prime lenses are similar in weight across the series, which means you typically will not need to rebalance a gimbal when switching between Athena lenses. The series standardizes gear positions: most lenses in the range share a 77mm front filter thread, with the 14mm being the exception.

The lenses use standard 0.8 module focus and iris gears, making them compatible with common follow focus systems and matte boxes used in professional production.

For macro and close-up work, NiSi offers a 77mm close-up lens (sold separately) that reduces minimum focus distance and enables stronger close-focus effects on Athena lenses that accept 77mm accessories.

Specifications

FAQ

Question: Will the Athena 40mm T1.9 E-Mount with Drop-In filter work on my Sony FX9?
Answer: No. The Sony FX9 camera cannot use the E-Mount version that includes Drop-In filters. If you use the FX9, choose the E-Mount version without the Drop-In filter or consider another compatible mount.

Question: Do I need to change gimbal balance when I swap to a 40mm Athena from another Athena lens?
Answer: You generally do not need to rebalance a gimbal when switching among Athena lenses because the series maintains similar weight across lenses. This consistency helps speed up lens changes during shoots.

Question: How do I ensure I can reach infinity focus with this lens?
Answer: To obtain infinity focus and clear images, use the Drop-In clear filter on RF-, L-, G- and E-mount versions that support it, and use the rear filter on PL-mount versions as specified by NiSi.

Question: Can I use standard follow focus and matte box systems with the 40mm Athena?
Answer: Yes. The lens uses a standard 0.8 mod gear for both focus and iris, making it compatible with most professional follow focus systems and matte boxes.

Question: Is there an option for close-up or macro work?
Answer: Yes. NiSi offers a 77mm close-up lens (sold separately) that reduces the minimum focus distance on Athena lenses that accept 77mm accessories, enabling stronger close-focus effects.