Convert MEF to PNG — Free Online Converter
Convert Mamiya Raw Format (.mef) to Portable Network Graphics (.png) online for free. Fast, secure image conversion with no watermarks or registration...
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How to Convert
Upload your .mef file by dragging it into the upload area or clicking to browse.
Choose your output settings. The default settings work great for most files.
Click Convert and download your .png file when it's ready.
About MEF to PNG Conversion
PNG provides lossless compression for Mamiya MEF RAW conversions, preserving every pixel of the demosaiced medium format sensor data without any quality degradation. Converting MEF to PNG produces a universally compatible file that maintains the extraordinary detail captured by Mamiya 645AFD, 645DF, and Phase One back-equipped cameras at 22-80+ megapixels.
For medium format workflows where lossless quality is essential but TIFF's professional overhead is unnecessary, PNG offers an excellent middle ground. It is smaller than uncompressed BMP, lossless unlike JPEG, and supported by every operating system, browser, and photo editor. The main trade-off is larger file sizes compared to lossy JPEG.
Why Convert MEF to PNG?
PNG preserves the maximum quality from medium format sensor data in a universally accessible format. Unlike JPEG, PNG introduces zero compression artifacts, making it the ideal output format when medium format captures will undergo further editing, compositing, or color grading. Each pixel of the demosaiced MEF data is preserved exactly.
Mamiya medium format cameras represent a significant investment in image quality, and lossy compression discards some of that investment. PNG ensures that none of the demosaiced sensor data is lost to compression, while still providing a file format that opens in every application from basic system viewers to professional editing suites.
Common Use Cases
- Create lossless archival copies of Mamiya medium format captures in a universally supported format
- Convert MEF files for retouching workflows where lossless quality prevents compression artifact accumulation
- Prepare Phase One medium format photographs for compositing work requiring pixel-perfect source material
- Generate lossless web-ready copies of medium format product photography for e-commerce platforms
- Build lossless digital archives of Mamiya studio sessions for long-term preservation
How It Works
LibRaw (via Sharp) decodes the MEF file, interpreting the medium format sensor's Bayer pattern at 14-16 bit depth and applying camera-specific white balance, color matrix, and gamma correction. The demosaiced image is compressed using PNG's DEFLATE algorithm at the optimal compression level, producing a lossless output at 24 bits per pixel. For medium format sensors, PNG file sizes are substantial — a 60 MP capture produces a PNG of approximately 50-80 MB with DEFLATE compression.
Quality & Performance
PNG compression is mathematically lossless — the decoded PNG contains the exact pixel values output by the demosaicing algorithm. Zero quality is lost from the format conversion. The 14-16 bit RAW depth is reduced to 8-bit PNG (standard), though 16-bit PNG output is also possible for maximum tonal range preservation. The full resolution of the medium format sensor is maintained.
Device Compatibility
| Device | MEF | PNG |
|---|---|---|
| Windows PC | Partial | Native |
| macOS | Partial | Native |
| iPhone/iPad | Partial | Native |
| Android | Partial | Native |
| Linux | Partial | Native |
| Web Browser | No | Native |
Tips for Best Results
- 1PNG is ideal for medium format work that will be edited further — lossless quality prevents generation loss
- 2For web delivery, resize medium format PNGs to practical dimensions (2000-3000 px long edge)
- 3Use 16-bit PNG if you plan aggressive color grading or compositing with the medium format data
- 4TIFF is better for institutional archival; PNG is better for general-purpose lossless storage
- 5Keep original MEF files as ultimate masters — they contain more data than any 8-bit format can represent
MEF to PNG is the recommended lossless conversion for medium format photographs that need universal compatibility. Larger file sizes are the trade-off for pixel-perfect quality preservation.