ARRI's proprietary uncompressed raw format for maximum image quality and post-production flexibility.
Technical Details
ARRIRAW delivers linear Bayer-pattern data directly from the CMOS sensor with a color depth of 16 bits per pixel. The data rate at 4K/24fps is approximately 1.8 GB/minute; for the ALEXA 65, it increases to up to 7.8 GB/minute. The format uses logarithmic encoding (Log-C), with native ISO values ranging from 160 to 6400. It is stored in .ari files with integrated timecode and metadata. Internal color filtering is minimal, preserving maximum flexibility in post-production.
History & Development
ARRI introduced ARRIRAW in 2010 with the ALEXA, following increasing demands for higher image quality from digital cinema cameras. In 2015, the ALEXA 65 expanded the format to 6.5K resolution for IMAX productions. The ALEXA Mini LF (2019) brought large-format support, while current ALEXA 35 cameras (2022) record ARRIRAW at up to 120fps at 4K. Continuous development focuses on higher resolutions and frame rates with consistent color science.
Practical Use in Film
Emmanuel Lubezki used ARRIRAW for "Birdman" (2014) to capture complex Steadicam movements with maximum detail preservation. "Blade Runner 2049" (2017) employed the format for elaborate VFX shots, as the raw data allowed for precise color keys. Typical workflows involve ARRI Color Science (ACES) in DaVinci Resolve or Baselight. Advantages: maximum color correction flexibility and noise reduction. Disadvantages: immense storage requirements and computationally intensive processing.
Comparison & Alternatives
ARRIRAW competes with RED's R3D format but offers more natural skin tones through ARRI's color science. Sony's RAW formats (X-OCN) achieve similar quality at lower data rates. Canon Cinema RAW Light compresses more but reduces flexibility. ARRIRAW remains the standard for high-end productions, while ProRes RAW suffices for smaller budgets or documentary work. The choice depends on the post-production pipeline, budget, and desired image aesthetic.
Current News
The ARRI ALEXA 35 continues to rely on ARRIRAW as its native recording format, utilizing a 4.6K Super 35 sensor. The camera combines the proven RAW format with the new REVEAL Color Science for more precise color reproduction and an expanded dynamic range. ARRIRAW thus remains a central component of ARRI's current camera generation.
Current News
The ARRI ALEXA 35, with its 4.6K Super 35 sensor, continues to use ARRIRAW as its native recording standard. In addition to the proven ARRIRAW format, the camera also supports ProRes recording, allowing productions to choose between maximum image quality and optimized workflows depending on their requirements. The integration of REVEAL Color Science further expands the possibilities for RAW post-processing.