This is a collection of spectral sensitivity data for digital cameras, with the aim of improving the construction of camera profiles for raw processing digital images.

In making an image from a digital camera's raw capture, a transform of the data to some defined colorspace, such as AdobeRGB or sRGB, is required to make the image look right to the viewer. The input data description to this transform is usually a 3x3 matrix defining some sort of chromatic bound, often called a "compromise matrix" These matrices are usually determined from a camera image of a color target, where the reference values of the color patches are used to determine the matrix extents. This process is fraught with collection errors, primarily due to the presence of 'glare' on the target. Additionally, while the 3x3 matrix is usually sufficient to transform to pleasing colors, extreme colors with gradation are not handled well by that simplistic transform.

To transition extreme colors and retain some sense of their gradation, a non-linear transform is required. This is enabled in the transform mechanisms by the replacement of the matrix with a lookup table, or LUT. But, to effectively support the non-linear lookups, larger patch-count targets are required, or in the best case, data representing the camera's spectral sensitivity in each of the three bandpass filters comprising the sensor mosaic. This collection supports that best case.

The collection starts with the three cameras I own, using a DIY spectroscope to capture the sensitivity measurements. The data is reduced with software I wrote specifically for the purpose, ssftool: https://github.com/butcherg/ssftool. The included ICC profiles were produced from that data using dcamprof: https://github.com/Beep6581/dcamprof

The collection is organized in subdirectories for each manufacturer, with corresponding subdirectories for each camera. As I find the oppurtunity to measure more cameras they will be added, and if a subsequent measurement for a particular camera improves the profile max deltaE of the posted data, it will be replaced. Data history can be regarded using git log; commits will always identify the affected make and model of each camera being updated. Data from other collections may be added depending upon receiving permission to do so with the respective copyright/license, but all data measured by myself and posted to this repository is Copyrighted by Glenn Butcher with all rights reserved and carries this Creative Commons license:

ssf-data by Glenn Butcher is licensed under CC BY-NC-SA 4.0