BMP vs ORF
A detailed comparison of BMP Image and Olympus RAW ORF — file size, quality, compatibility, and which format to choose for your workflow.
BMP Image
Raster & Vector ImagesBMP is an uncompressed raster image format native to Windows. Files are large but preserve exact pixel data with no compression artifacts. Rarely used on the web due to file size.
About BMP filesStrengths Comparison
BMP Strengths
- Dead-simple format — trivially easy to read and write.
- Lossless and uncompressed — perfect bit-exact pixel storage.
- Universally supported in Windows applications since 1985.
- Supports 1, 4, 8, 16, 24, and 32-bit color depths.
ORF Strengths
- Compact files relative to sensor size (Four Thirds is smaller than APS-C).
- Computational photography features (Live Composite, Pro Capture) baked into format.
- Stable across 20+ years of Olympus/OM SYSTEM bodies.
- In-body stabilization means ORF handheld shots rival tripod work.
Limitations
BMP Limitations
- Enormous file sizes — no meaningful compression in typical use.
- Not a web format — browsers support it but nobody serves BMPs over HTTP.
- No metadata support (no EXIF, no ICC profile in practice).
- Multiple header versions mean "a BMP" is ambiguous — parsers must handle several variants.
ORF Limitations
- Smaller sensor means less dynamic range than full-frame raws.
- Lossy compressed ORF is the default — hidden quality loss.
- Market share is small; fewer tutorials and fewer Lightroom profiles.
- Proprietary with no official spec.
Technical Specifications
| Specification | BMP | ORF |
|---|---|---|
| MIME type | image/bmp | image/x-olympus-orf |
| Extensions | .bmp, .dib | — |
| Compression | None (typical); RLE 4/8 bit (rare) | — |
| Color depths | 1, 4, 8, 16, 24, 32 bits per pixel | — |
| Byte order | Little-endian | — |
| Extension | — | .orf |
| Container | — | TIFF/EP with Olympus MakerNote |
| Sensor format | — | Four Thirds / Micro Four Thirds |
| Bit depth | — | 12 or 14-bit |
Typical File Sizes
BMP
- Small icon (32×32) 4 KB
- Screenshot (1920×1080) ~6 MB
- 4K image (3840×2160) ~25 MB
- Scanned A4 at 300 dpi ~25 MB
ORF
- 20 MP ORF (OM-1, E-M1 III) 18-25 MB
- 50 MP Hand-Held High Res composite 60-80 MB
- 80 MP Tripod High Res ORF 100-140 MB
Ready to convert?
Convert between BMP and ORF online, free, and without installing anything. Encrypted upload, automatic deletion after 2 hours.
Frequently Asked Questions
BMP (Bitmap) is a raster image format developed by Microsoft for Windows. It stores images with no compression by default, resulting in large file sizes but pixel-perfect quality. It has been part of Windows since version 1.0.
ORF (Olympus RAW ORF) 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 ORF when its particular strengths match the publishing target.
BMP files open in Windows Paint, Photos, macOS Preview, GIMP, Photoshop, and virtually any image viewer. All Windows applications support BMP natively.
Most desktop photo viewers (Windows Photos, macOS Preview, GIMP, Photoshop, Affinity Photo) open ORF natively. On mobile, iOS Photos and Google Photos display ORF 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 ORF to JPG or ORF to PNG converter.
PNG is better than BMP in almost every scenario since it provides lossless compression (smaller files), transparency support, and wider cross-platform use. BMP is mainly relevant for legacy Windows applications.
Upload the ORF 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.