About PEF Files
Pentax RAW
PEF is the RAW image format used by Pentax DSLR cameras, containing full sensor data.
Family
Raster & Vector Images
Extension
.pef
MIME Type
image/x-pentax-pef
Can Use As
HOW PEF
CAME TO BE.
PEF — Pentax Electronic Format — is Pentax\u2019s proprietary raw format, debuting in 2003 with the *ist D, Pentax\u2019s first DSLR. Like every other major vendor\u2019s raw format, PEF is a TIFF/EP variant with Pentax\u2019s own makernotes storing sensor data, lens info, and shooting parameters. Pentax has always been the quirky underdog — Ricoh acquired Pentax\u2019s imaging business in 2011, but the PEF format carries on through the K-1 Mark II, K-3 Mark III, and every K-series DSLR.
Pentax is one of the few vendors that also encourages use of Adobe DNG — the K-series cameras can write DNG directly instead of PEF if the user prefers archival openness. That dual-format policy (and Ricoh/Pentax\u2019s open-standards philosophy more broadly) is one reason Pentax DSLRs retain a cult following among photographers who value long-term file portability.
CURIOSITIES &
TRIVIA.
Pentax cameras can write DNG directly as an alternative to PEF — one of the few mainstream vendors that offers the choice.
Ricoh acquired Pentax's imaging division in 2011, bringing PEF into the Ricoh portfolio alongside their own GR series.
The K-1 Mark II's 36 MP PEF files are among the largest raws in consumer DSLRs — typically 45-60 MB.
Pentax K-series bodies have in-body shake reduction — a feature Pentax pioneered before Sony or Canon had it.
Pentax-Ricoh has kept a working DSLR lineup through the mirrorless transition longer than any other vendor.
STRENGTHS &
LIMITATIONS.
Strengths
- Full Pentax sensor data with 14-bit or 12-bit depth.
- Rich Pentax makernotes for lens and filter metadata.
- DNG alternative available on body — user choice of archival openness.
- Every major raw processor supports PEF.
Limitations
- Proprietary with no public spec.
- Niche market share — Pentax DSLR sales are a fraction of Canon/Nikon/Sony.
- Lightroom profile coverage trails the Big Three.
- Smaller third-party ecosystem.
Typical Sizes & Weights
24 MP PEF (K-3 Mark III)
30-40 MB
36 MP PEF (K-1 Mark II)
45-60 MB
Technical Specifications
- MIME type
- image/x-pentax-pef
- Extension
- .pef
- Container
- TIFF/EP with Pentax MakerNote
- Bit depth
- 12 or 14-bit
- Alternative
- DNG (selectable in-camera on K-series)
CONVERT FROM
PEF
Common Use Cases
Pentax DSLR photography
Related Formats
Popular comparisons
PEF vs WEBP
Differences, file size, and when to choose each format.
PEF vs AVIF
Differences, file size, and when to choose each format.
PEF vs GIF
Differences, file size, and when to choose each format.
PEF vs BMP
Differences, file size, and when to choose each format.
PEF vs TIFF
Differences, file size, and when to choose each format.
PEF vs ICO
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Popular PEF conversions
The most-requested destinations when starting from PEF.
Frequently Asked Questions about PEF
Frequently Asked Questions
PEF (Pentax RAW) is an image format used to store raster graphics — a two-dimensional grid of pixels describing a picture. It is part of the raster & vector images family and designed around a specific trade-off between file size, visual fidelity, and feature support (transparency, colour depth, compression type). Photographers, web designers, and content creators choose PEF when its particular strengths match the publishing target.
Most desktop photo viewers (Windows Photos, macOS Preview, GIMP, Photoshop, Affinity Photo) open PEF natively. On mobile, iOS Photos and Google Photos display PEF in the gallery when supported by the OS. If the format is rare or new, convert to JPG or PNG first — both are universally readable — using our PEF to JPG or PEF to PNG converter.
Upload the PEF to KaijuConverter and pick a target format (JPG, PNG, WebP, HEIC, TIFF, BMP, SVG, PDF). The conversion runs in the browser via ImageMagick and returns a download in seconds. No account or installation required; both input and output delete automatically within two hours.
It depends on the task. JPG is the smallest file size for photographs; PNG is lossless with transparency; PEF has its own niche that may favour colour depth, animation, or encoding efficiency over one or both of those. For the final web publish, test all three and measure file size plus visible quality on real content.