The STF Auto Stretch dialog allows a Shadows clipping value to be set. The meaning of this value has changed in the new 1.8 version STF, so a value used in a previous version will give different results now.
If you need to get the same results in the new 1.8 version STF, you can convert an old Shadows clipping to a new value as follows.
new = old * avgDev / (1.2533 * MAD)
where avgDev and MAD are the normalized values for your image listed in the Statistics process window. If these values are not displayed, click on the tool icon and enable them.
The meaning of the Target background value remains the same, so it needs no conversion.
In some of my old projects I set Shadows clipping and Target background for an initial stretch. I recorded these values in my processing notes. This technique lets me recreate the same result in the new version.
Thanks,
Mike
