RAW and Image File Formats

Raw / Output / Batch / EIP / IIQ / JPEG

Find out how Capture One works with RAW files and previously processed formats including TIFF and JPEG.

Capture One and RAW

Raw data is generated when light is received by the photodiodes on a sensor. Depending on the intensity of the light a stronger or weaker signal is generated. This data is read off and stored as unprocessed data on the memory card.

A RAW file contains more than one set of data. A DSLR file contains calibrated raw data plus the file header. A digital back file contains the actual raw data, calibration data for the digital back files and the file header information.

The file header is kept separate from the image data in digital back RAW files. The file header contains what is described as metadata; data about data. Metadata is information recorded by the camera at the time of capture and consists of the following:

  • Image Thumbnail (usually a TIFF, but sometimes a JPEG)
  • Time/Date
  • ISO
  • Exposure information
  • White Balance (that the image was shot at)
  • Contrast curve
  • Recorded pixel size
  • Camera data (shutter speed/aperture/focal length etc)

More than 100 pieces of data are stored together.

The White Balance determines how the file will look when Capture One creates the preview. The ISO, exposure data and camera model information are used to calculate the noise reduction used by Capture One.

Capture One de-mosaics the RAW-file information from the Bayer filter mounted onto the sensor to produce image files with three colors per pixel. This process uses an extremely sophisticated and patented algorithm.

The in-camera ISO and White Balance settings are applied to the image together with the formula developed for Capture One when the preview is created and displayed in the Viewer, in what is called a variant. Once the variant file has been produced, nearly all the variables can be changed such as Contrast Curves, Sharpening and Color Balance.

One of the really big advantages with RAW files is the ability to change the white balance after the image has been captured – this is often not possible with lossy formats like JPEG. The adjustments made to the image in Capture One are applied to the preview and added to a settings file. No changes are made to the raw data at any time.

Once the process button is pressed, raw data is processed using the settings file. At this point the true pixel-based image is formed and output to specific dimensions.


Many DSLR and smaller digital cameras can create a JPEG at very high quality. These files can generally be further adjusted and improved in Capture One. Capture One supports viewing and editing of JPEG (RGB) and TIFF (RGB) files. Like RAW files, Capture One produces a preview and settings file, collectively called a variant, for each JPEG and TIFF file and works on those instead.  However, it might not be possible to edit files in Capture One if you have JPEGs or TIFFs rendered in CMYK or Grayscale.

JPEG and TIFF are files that have already been processed to a certain level, either by a camera’s internal software or in conversion software such as Capture One. When Capture One locates a file, the White Balance (WB) setting is determined by the camera that captured the image or by the conversion software that originally created the file. The White Balance setting can be adjusted, but only to a limited extent. Note, a JPEG and TIFF file usually has a significantly smaller dynamic range compared to RAW capture. This might result in burned out or darkened areas when the auto White Balance is applied or if the White Balance Picker tool is used to set White Balance.

More about variants

Variants are used by Capture One to display the original RAW, JPEG, TIFF, DNG, PNG, or PSD source files and to store the adjustments you have made. To understand the concept of variants you need to first see Capture One as a kind of non-destructive rendering engine. This non-destructive approach means edits are never saved to the original files. Capture One reads the original source files and then determines how they should look on-screen, based on some default factory parameters. A small preview file for each of your images is then made and this is what you see in the viewer.

When you adjust an image, the instructions are written to a small BLOB of data called settings. The application in real-time then re-reads the updated settings, and then updates the preview. We call this virtual representation a variant. In effect, what you are looking at on-screen is always a virtual representation of what the final file will look like once the image is finally processed or exported. This concept of a variant thus exists as a sort of in-between of the source file and the final file.

Each variant refers by name and format to the source images (wherever they’re stored), so you can logically connect them to the previews on screen. There are many benefits to variants: they can be copied as many times as you like and can even exist in more than one place (in the form of albums). All of these virtual copies can exist as a representation of just one original source image. When it comes to exporting the final file, Capture One doesn’t make any changes to your source images. Instead, it combines the original image data and adjustments you’ve made and makes a copy in the chosen format that a pixel editor can read. 

Variants are used by Capture One to display the original RAW, JPEG, TIFF, DNG, PNG, or PSD source files and to store the adjustments you have made.