ACR 3.x supports linear curves. Finally. Good news. Curve is limited to 16 points - not so good news, as the common scale is 20 points. The curve in ACR acts in linear space, but is using logarithmic scale only. 3eV range from mid-gray to black in compressed in 1/4 range of the curve, another quarter is waisted, being below shadow level. Thus the whole range is shifted, and what should be shadows is represented by 3/4 tone on the curve. Sad news.