NiSi Cine Lens Athena Prime 25mm T1.9 L-Mount

NiSi Athena Prime 25mm T1.9 L-Mount – T1.9 aperture for soft bokeh and full-frame coverage

This NiSi Athena Prime 25mm in L‑Mount delivers the T1.9 maximum aperture found in the Athena series, enabling shallow depth of field and attractive background separation. It is part of the Athena Cine Lenses family, designed for cinematography and video work where consistent exposure and matched handling across a lens set matter.

Key optical features

The Athena series offers an image circle of 46mm, making the lenses suitable for full‑frame and large‑format sensors. The 25mm shares the series’ characteristics for image quality, including ultra‑low chromatic aberration and improved micro‑contrast control. These attributes help capture finer image details while maintaining consistent exposure through T‑stop ratings.

Aperture and light transmission

The NiSi Athena primes use T‑stop ratings to communicate actual light transmission. In the series, the 25mm has a maximum aperture of T1.9. This fast aperture allows the 25mm to produce a shallow depth of field and stronger subject separation when needed, while maintaining exposure consistency with matching focal lengths in the set.

Compatibility and mounts

The Athena Prime lenses are available in multiple mount options. The series includes ARRI PL, Canon RF, Sony E, Panasonic/Leica L and Fuji G mounts. This specific listing is for the L‑Mount 25mm, and the L‑Mount version supports the series’ Drop‑In filter option.

Drop‑In filter system and notes

The Athena series features a proprietary rear filtration system with a Drop‑In filter mount on RF, L and G mounts. E‑Mount lenses are offered in two versions (with and without Drop‑In filter) while PL‑mount lenses use a rear filter. NiSi provides weather sealing for the Drop‑In filter assembly.

• Sony FX9 cameras cannot use the E‑Mount version with Drop‑In filters.
• It is important to use the Drop‑In clear filter on RF, L, G and E mounts, and the rear filter on PL‑mount lenses, to achieve infinity focus and obtain clear images.

Matched handling and gimbal workflow

NiSi designed the Athena primes to behave consistently across the set. All lenses in the series are similar in weight, so you do not need to rebalance your gimbal when switching between Athena lenses. Aperture and focus rings are matched across the range for uniform tactile control during shoots.

Mechanical and focus details

The Athena primes provide a 300° focus rotation and fluorescent focus scales displayed in both imperial and metric units for precise focus pulls. They use standard 0.8 mod focus and iris gears, making them compatible with a wide range of follow focus and matte box systems.

Filters and close‑up options

Except for the 14mm lens, Athena primes share a 77mm front filter thread. NiSi also offers a 77mm close‑up lens (sold separately) to reduce minimum focus distance and create macro effects when needed.

Who this lens is for

Choose the NiSi Athena Prime 25mm L‑Mount if you need a 25mm cine prime with a T1.9 aperture that integrates into a matched lens set. It suits filmmakers working on full‑frame or large‑format cameras who want consistent exposure, matched handling, and options for rear filtration and macro close‑ups.

FAQ

Question: Is the L‑Mount 25mm compatible with full‑frame and large‑format sensors?
Answer: Yes. The Athena series provides a 46mm image circle, which makes the lenses suitable for full‑frame and even large‑format sensors.

Question: Do I need a special filter to reach infinity focus on the L‑Mount 25mm?
Answer: Yes. For L‑Mount (and RF, G and E where applicable), you must use the Drop‑In clear filter to achieve infinity focus and clear images. PL‑mount lenses require the rear filter. NiSi supplies a weather‑sealed Drop‑In option for applicable mounts.

Question: Will I need to rebalance my gimbal when switching to this 25mm from other Athena lenses?
Answer: No. The Athena series lenses are similar in weight and designed so you do not need to rebalance your gimbal when switching between Athena primes.

Question: Can I use follow focus and matte boxes with this lens?
Answer: Yes. The lens has standard 0.8 mod focus and iris gears, and matched aperture and focus rings for compatibility with most follow focus and matte box systems.

Question: What other focal lengths are available in the Athena range and how do their apertures compare?
Answer: The full Athena range covers focal lengths from 14mm (T2.4) through 18mm (T2.2), 25/35/40/50/85mm (T1.9), up to 135mm (T2.2). This provides options from super‑wide to portrait focal lengths with consistent T‑stop information across the set.