How can I tell whether a camera applies processing to RAW files?
Asked 8/16/2017
2 views
2 answers
0
For some uses, especially astrophotography and scientific-style imaging, photographers want RAW files that are as close as possible to the sensor data. Some cameras are known or suspected to apply steps such as noise reduction or other corrections before writing the RAW file. Is there any reliable way to find out what processing a particular camera applies to its RAW data, and whether it can be disabled?
Originally by Photography Stack Exchange contributor. Source · Licensed CC BY-SA 4.0
Photography Stack Exchange contributor
8y ago
2 Answers
1
Is there any way to know what pre-processing a particular camera might be doing to its sensor data?
You could ask the manufacturer of the particular camera. If they are nice they will tell you (although I'm not aware of any publicly available lists).
If they are even more nice they may offer an option to turn any pre-processing off for raw data, although you may not want all of that and keep some calibrations (like brightness corrections?).
The chance is pretty low though because this is usually only built-in for scientific grade cameras.
An alternative would be to try to detect this pre-processing steps in the raw data by a standardized test experiment. You could take images of an array of point-like light sources of variable brightness and if the single images remain smooth independent of the brightness you know that some denoising has been applied (because the SNR of real raw data usually increases with lower brightness). This could also be used to compare different cameras and select the one with the best performance and the lowest amount of pre-processing (might be a trade-off though).
Originally by user55606. Source · Licensed CC BY-SA 4.0
user55606
8y ago
0
Generated from our catalog & community — verify before relying on it.
Usually there is no complete public specification for what a camera does before writing a RAW file. Manufacturers may apply some undocumented processing, and they often do not publish full details.
Your practical options are:
- Ask the manufacturer. Occasionally they will disclose some processing steps or whether any can be disabled, but this is uncommon.
- Test the RAW data yourself. Controlled test shots can reveal whether smoothing, noise reduction, clipping, or other corrections seem to be present.
- Inspect the files with specialist RAW-analysis tools. Community tools and reverse-engineered documentation are often the best source of insight into how a camera’s RAW data is structured and interpreted.
In practice, many cameras apply at least some “secret sauce” to RAW output, and full control is more typical of scientific cameras than mainstream consumer models. So the most reliable approach is to look for independent testing and analyze sample RAW files rather than expect an official published list.
Recommended products
UniqueBot
AI8y ago
Your Answer
Related Questions
Are there RAW-like files that capture more dynamic range than a single camera RAW?
What does an unprocessed RAW file actually look like?
How much in-camera processing is applied to a RAW file?
How can I disable darktable's automatic processing on RAW files?
What software can automatically apply basic RAW adjustments to speed up editing?