What is the Curve section of the Base Characteristics tool and how should I use it to adjust my images? Can I change the curve after I shoot?
The Film Curve selection changes the way the values in the file are shown in the image. It can be used to raise or lower contrast on a very fundamental level.
The Base Characteristics tool offers several camera film curve settings that you can select to match different shooting situations. The different film curves affect how tonal values are mapped to the shadows, mid-tones, and highlights. It is a very fundamental parameter of the Capture One's rendering pipeline affecting all other adjustments besides the ICC profile and white balance. As such, it can be particularly useful in recovering details from shadows or highlights. Different film curves are available in the dropdown list depending on the camera used as different curves are made for different camera bodies.
You can change the curve applied to the capture by clicking on the Curves dropdown menu in the Base Characteristics tool. It is also possible to set a specific ICC Profile and Film Curve as defaults for a particular camera model.
Auto. Capture One will automatically select one of the film curves below based on what the software has listed as 'default' for the specific camera. In most cases, it is the Film Standard Curve.
Film Standard. It is designed to give a similar look to transparency film with deep blacks and bright mid-tones and highlights. It is reminiscent of a standard S-Curve.
Film Extra Shadow. It offers similar tone characteristics as the standard one but with less contrast in the shadows. This option is useful for recovering details in deep shadows without affecting mid-tones or highlights.
Film High Contrast. It has higher contrast than Film Standard, but with deeper shadows and brighter highlights.
Linear Response. It is a curve that has an extremely reduced contrast and is intended to offer maximum control over the tone mapping using the Curves tool. It has a slight highlight roll-off protection near the absolute maximum values. Linear Response is useful for recovering both shadow and highlight details that may be lost in the Film Standard, Extra Shadow or High Contrast curves.
Linear Scientific. This is a completely linear curve response used for ICC profile creation. This film curve should be used with care as there is a risk of overexposure in the highlight areas. Unlike Linear Response, there is no roll-off towards the maximum values, so specular highlights will have a distinct hard edge as values decrease. This is only available for some camera and digital back models.