RAW Image Support¶

Acorn has the ability to open RAW files that are supported by macOS. A list of supported RAW formats can be found from Apple's support website:

When you open a RAW image in Acorn, the RAW Import Window will appear. You can adjusting exposure, bias, boost, shadow boost, noise reduction, temperature, and more. You can set the color profile, image depth, and the width and height.

At the bottom of the window is a live histogram of your image which updates as you adjust the options. If you decide you want to revert to the original image, you can click the reset button in the lower left hand corner of the window.

You can also save and load presets using the action menu in the lower left corner of the window.

RAW Presets After adjusting the various sliders, there is the option to save the adjustments as a preset for future use. Click on the action menu in the lower lefthand corner of the window, and choose ‘Save Preset’.

Exposure
Adjusting the exposure changes the lightness or darkness of the entire image.

Baseline Exposure
Adjusting the baseline exposure changes the lightness or darkness of the entire image. This value is set when the image is captured in the camera.

UI{Boost} A value that indicates the amount of global tone curve to apply to the image. A value of 0 indicates no global tone curve (linear response), and a value of 1 indicates full global tone curve. The default value is 1.

Shadow Boost
The amount to boost the shadow areas of the image. Can be used to lighten details in shadows. This has no effect and is disabled if Boost is 0. A value less than 1 will darken the shadows. A value greater than 1 will lighten the shadows.

Shadow Bias
The amount to subtract from shadows the image.

Luminance Noise Reduction
A value to control the amount of luminance noise reduction to apply to the image. The default value will vary from image to image, and not all images may support this setting.

Color Noise Reduction
A value to control the amount of chroma noise reduction to apply to the image. The default value will vary from image to image, and not all images may support this setting.

Moire Reduction
A value to control the amount of moire artifact reduction to apply to high frequency areas of the image. The default value will vary from image to image, and not all images may support this setting.

Temperature
Changes the photo colors from warm to cool.

Tint
The amount of white balance based on tint values to apply to the image.

Contrast
Control the amount of local contrast to apply to the edges of the image. The default value will vary from image to image, and not all images may support this setting.

Detail
Control the amount of detail enhancement to apply to the edges of the image. The default value will vary from image to image, and not all images may support this setting.

Tone Mapping
Control the amount of local tone curve to apply to the image. The default value will vary from image to image, and not all images may support this setting.

Sharpness
Control the amount of sharpness to apply to the edges of the image. The default value will vary from image to image, and not all images may support this setting.

Color Profile
Choose which color profile to use when finalizing the image.

Depth
Choose the pixel depth from 8, 16, or 32 bits per channel. The larger the depth, the more fidelity in colors are the larger the file size of the image.

Width and Height
Adjusts the pixel dimensions of the image.

Lens correction
Toggles lens correction on or off for the image. Not all images may support this setting.

Gamut mapping
Toggles gamut mapping on or off for the image.

Pressing OK will open the image in Acorn for further editing. When you save your opened RAW file for the first time in Acorn, a new file will be created. Acorn does not support saving RAW files.

Tips

You can double click a label to reset its value.
The various shortcuts for zooming in and out work for the preview view (⌘+, ⌘-, ⌘0, ⌘1, ⌘2, etc…)