Sirui IronStar 75mm, 100mm & 135mm Full-Frame 1.5x Anamorphic Lenses

Shared Mechanics Across the Line

The three new optics carry identical physical and electronic specs. All use a 46mm image circle, 95mm front diameter, and 92mm threaded filter acceptance. Focus and iris rings run standard 0.8 pitch gears with a 270-degree focus throw — compatible with follow focus and wireless motor systems without adapter hardware.

A back focus adjustment ring sits at the mount interface. Flange depth calibration happens without shims or mount disassembly. For rental houses and owner-operators rotating between camera bodies, this cuts bench time per prep.

Aperture breakdown:

• 75mm — T1.9

• 100mm — T2.8

• 135mm — T2.8

Optical Claims vs. Measurable Performance

Sirui markets the optical formula as corrected for spherical aberration and edge color fringing. Multiple cylindrical elements are stated to suppress distortion, dispersion, and clarity loss. Focus breathing is listed as "well-controlled."

Manufacturer claims on anamorphic breathing require independent verification. Squeeze ratio consistency across focus pulls is a metric rarely published in spec sheets. Request MTF charts at infinity and minimum focus before purchasing for narrative work where focus pulls carry visual weight.

The T-stop delta between the 75mm (T1.9) and the 100mm/135mm (T2.8) is a real limitation. Matching exposure across the full kit requires ND compensation or lighting adjustments at the long end. Factor this into scene planning for low-light interiors or night exteriors.

Kit Architecture and Format Coverage

Combined with the existing 35mm T1.9, 45mm T1.9, and 60mm T1.9, the lineup spans wide to medium-tele in a unified 1.5x squeeze. Total cost for all six lenses: $5,994 USD. For full-frame or Vista Vision cinematography, this is a coherent anamorphic system at sub-$10K pricing.

Mount interchangeability extends utility. ARRI PL fits Alexa Mini LF, Alexa 35, and most large-format cine bodies. Canon EF mounts cover EOS C-series, RED Komodo, and Blackmagic cameras with EF lock. Verify back focus calibration after every mount change — tolerances compound across the optical path.

Warranty Terms

Sirui offers free replacement for three years against non-human damage, valid with proof of purchase. Lifetime paid repair service covers human-caused failures including drops, water ingress, and physical modifications. Standard third-party optics warranty structure — clarify "non-human damage" scope before assuming accidental impact qualifies.

Practical Take

Three full-frame anamorphic primes at $999 each. Shared mechanics, swappable mounts, serviceable warranty structure. The T-stop spread across focal lengths is the primary optical trade-off. Test breathing and edge resolution on your specific sensor before committing to a six-lens rental package.