Image MIME Reference
Nikon-NEF
Nikon Electronic Format
image/x-nikon-nef
VS
Sony SR2 Raw Image
image/x-sony-sr2
Sony-SR2
A complete technical comparison of Nikon Electronic Format and Sony SR2 Raw Image — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | Nikon-NEF | Sony-SR2 |
|---|---|---|
| Transparency (Alpha) | ✕ No | ✕ No |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | Yes | Yes |
| EXIF Metadata | Yes | Yes |
| ICC Color Profile | Yes | Yes |
Nikon Electronic Format
image/x-nikon-nef
Extension
.nef
Container
TIFF
Compression
Uncompressed / Lossless Compressed / Lossy Compressed (High Efficiency)
Algorithm
NoneNikon Proprietary LosslessNikon High Efficiency Lossy
Color Depth
12-bit (Per Channel), 14-bit (Per Channel)
Developed by
Nikon Corporation
Released
1999
Magic Bytes
49 49 2A 00 or 4D 4D 00 2A
Sony SR2 Raw Image
image/x-sony-sr2
Extension
.sr2
Container
TIFF-based (Proprietary)
Compression
Uncompressed / Sony Proprietary Lossless
Algorithm
NoneSony Proprietary Lossless
Color Depth
12-bit (Per Channel)
Developed by
Sony Corporation
Released
2005
Magic Bytes
49 49 2A 00
Browser Support Comparison
| Browser | Nikon-NEF | Sony-SR2 |
|---|---|---|
|
|
✕ | ✕ |
|
|
✕ | ✕ |
|
|
✕ | ✕ |
|
|
✕ | ✕ |
|
|
✕ | ✕ |
Nikon-NEF
Nikon-NEF Strengths
- Retains maximum sensor data, allowing extreme recovery of highlights and shadows that would be permanently lost in a JPEG
- White balance, sharpening, and color profiling are saved as metadata instructions rather than 'baked in', meaning they can be completely altered in post-production without degrading the image
- Embeds a high-quality JPEG preview inside the raw file for rapid culling and viewing
Limitations
- Proprietary format means it requires constant updates to raw processing engines every time Nikon releases a new camera model
- Produces very large file sizes (often 20MB to 50MB+ per image depending on sensor resolution and bit-depth)
- Cannot be directly embedded into web pages or used in standard HTML/CSS contexts
Sony-SR2
Sony-SR2 Strengths
- Retains raw, unprocessed sensor data from legacy cameras, allowing modern raw processors to extract vastly superior image quality than what was possible in 2005
- Utilizes a standard TIFF container structure, ensuring that community-maintained open-source decoding libraries (like LibRaw) can easily parse and maintain support for it indefinitely
Limitations
- Completely obsolete format that has not been utilized in a new camera release in over a decade
- MIME detection via magic bytes is unreliable due to TIFF header spoofing, requiring deeper EXIF inspection
- Cannot be natively viewed in web browsers or standard operating system image viewers without specialized decoders
When to choose which format
Nikon-NEF
Use Nikon-NEF when…
- Professional Digital Photography
- Non-destructive Image Post-Processing
- High Dynamic Range (HDR) Imaging Archival
Sony-SR2
Use Sony-SR2 when…
- Legacy Sony Cyber-shot/Alpha Photography
- Non-destructive Image Post-Processing
- Raw Imaging Archival