ZoneMapper: Adjusting the black point
One of several adjustments you can make to your photo using the ZoneMapper tool is the black point.
Black point adjustments are sometimes necessary for scanned positive color film images since the density of the film is never truly black. Additionally, there is always the possibility of having used an incorrectly profiled scanner that might have led to a black point that is too high.
To adjust the black point of your photo:
- Click the ZoneMapper tool button in the tool bar. (A new ZoneMapper tool will appear at the top of the tool stack.)
- Starting from the last zone, move the mouse upwards along the zones in the ZoneMapper until you find a zone that shows significant highlighting in the ZoneFinder.
- Click below that zone. A zone lock will appear (a thin, blue line with a little ‘X’ at its right).
- Drag the zone lock downwards. As you do so, your photo’s black point will decrease.
(a) before (b) after 
- Optionally:
- Create a mask using regions.
- Select a different blend mode.
- Adjust the Opacity slider.
- Make a color/luminosity selection.
- To delete a zone lock, click the little ‘X’ at its right.
