Did a test on my camera and you can, too!
http://phototechmag.com/characteristic-curves-for-digital-cameras/
>>2977449
supplementary info on imaging-resource
>>2977449
wrong y-axis label btw. its not log
How to read a curve
Ektar 100
[EXIF data available. Click here to show/hide.]
Camera-Specific Properties: Image-Specific Properties: Comment Screenshot Color Space Information sRGB Image Width 1125 Image Height 1194
Portra 400
[EXIF data available. Click here to show/hide.]
Camera-Specific Properties: Image-Specific Properties: Comment Screenshot Color Space Information sRGB Image Width 929 Image Height 984
>>2977456
Second paragraph. Whoops
[EXIF data available. Click here to show/hide.]
Camera-Specific Properties: Image-Specific Properties: Comment Screenshot Color Space Information sRGB Image Width 1079 Image Height 677
>>2977449
>>/g/
>>2977449
>Did a test on my JPEG and you can, too!
I have yet to see a second camera with non-proportional response (first was Kodak DCR IIRC).
>>2977740
thats with raw files though