What is a camera RAW file?
A camera RAW file contains the uncompressed and unprocessed data (pixels) obtained from the camera’s sensor captured at the time of exposure plus the image metadata – the unique information about how the image was captured. All camera RAW images; Uncompressed, Lossless Compressed, and Compressed Lossy can be adjusted/edited/processed in software such as Adobe’s Camera RAW Editor or Capture One. A RAW editor allows you to adjust all RAW images while preserving the camera RAW data available and saves your edits and adjustments as metadata associated with the original file.
What are the differences between a RAW file and a JPEG?
RAW files and JPEGs are not equal in the eyes of the camera. JPEGs do not contain all of the original data captured by the sensor, RAW files do. JPEGs are processed and compressed by the camera at the time of capture, RAW files are not. JPEGs can be made from RAW files, but RAW files can never be made from JPEGs. And, RAW files are significantly larger than JPEGs, they take more space to store on memory cards and external drives, they take longer to transfer from camera to computer during tethering and use more computer processing power to edit. The beauty of the RAW file is that it contains all the data captured by the sensor, it also is a very large file. This is where the benefit of Compression comes in.
What is the difference between RAW Compressed Lossy vs. RAW Lossless Compressed vs. RAW Uncompressed
- RAW Compressed Lossy – a reduced file size, where not all original image data is preserved – some of the data is deliberately eliminated during the compression process. Lossy Compression can cause visible image artifacts – this depends on the camera make and model as well as subject matter and lighting conditions during capture, artifacts may or may not be visible in final image usage.
- RAW Lossless Compressed is exactly what is it named, a lossless reduction of file size. All original file data is preserved.Similar to a ZIP file, the delivery file packet is compressed and reduced in size – actual file size reduction is based on the camera make and model, some cameras indicate a 20-40% files size reduction.
- RAW Uncompressed – No compression. This RAW file contains all of the original data and the large file size.
What are the most common use cases for shooting compressed RAW files?
Compression reduces RAW file size and smaller file sizes allow you to:
- Write to the card and transfer images to the computer in less time – whether you are tethering with a cable or over Wi-Fi, smaller files will transfer faster.
- Save space and money. Smaller files take up less storage space, use fewer camera cards and require less external storage space = money saved.
- Potential to increase continuous shoot time, smaller files take less space in the buffer, (depends on camera).
- Computer processing time can be reduced. Smaller files can be processed faster than larger files. Faster processing means faster workflow.
We recommend choosing the smallest Image Quality size necessary for your particular shoot, balancing the requirements of your client, the final image needs, the parameters of the type of tethering; cable or Wi-Fi, to a computer or to a mobile device, and the specific file capabilities of your camera.
Please refer to your camera’s user manual or your camera manufacturer’s website for more information about your camera.
- Camera User Manuals, See Chart Above