How to use it
- Drop in raw files.
- Wait while each is developed and saved as PNG.
- Download. Expect large files.
Why lossless after a raw
The point of shooting raw is to keep every bit of quality until the last moment. If the next step is retouching, compositing or grading in an app that cannot read your camera's raw format, a lossless PNG passes the developed image along without adding JPG artefacts. Compress once, at the very end, when the image is finished.
Bit depth
Raw files usually hold 12 or 14 bits per channel. The PNGs made here are 8 bits per channel, the same depth as JPG, because that is what browsers work with. For gentle edits that is plenty. For heavy grading, where smooth skies can band, use dedicated raw software that exports 16-bit TIFF.
File size
A 24 MP photo as PNG is typically 40 to 70 MB. That is the cost of lossless storage of a detailed photo. If you only need to view or share the photos, RAW to JPG is far more practical.
RAW and PNG compared
| RAW | PNG | |
|---|---|---|
| First released | Late 1990s, varies by maker | 1996 |
| Compression | Sensor data, uncompressed or lightly compressed | Lossless |
| Transparency | No | Yes, including soft edges |
| Animation or pages | No (holds a JPEG preview) | Only as APNG, rarely used |
| Best for | Editing photos with the most latitude | Screenshots, graphics, text and transparency |
| Support | Raw editors and camera software; not browsers | Universal |
Questions people ask
Is RAW to PNG lossless?
The step from the developed image to PNG is lossless. The development itself uses 8 bits per channel.
Why are the PNG files so big?
Photos compress poorly without loss. 40 MB or more per file is normal for modern cameras.
Can I get 16-bit output?
Not here. Use raw software that exports 16-bit TIFF.