13 Replies Latest reply on Apr 26, 2017 9:08 AM by adann

    Auto Whites and blacks in Lightroom -- what is behind this adjustment?

    adann

      When I Shift+double-click the white or black slider in Lightroom, what is Lightroom optimizing for?  I'd like to understand what is behind this adjustment so I can explain it to a student.

       

      In The Digital Negative, Jeff Schewe says the white and black sliders are for managing white and black clipping, which makes sense.

       

      However, when I shift+double-click the Black slider for the image below, I see I'm actually introducing clipping.  So what is Lightroom doing with this adjustment shortcut?

       

      Here's an unadjusted image:

      Screen Shot 2017-04-25 at 2.53.47 PM.png

      Here is the adjusted image after Shift+double-click on the Black slider:

      Screen Shot 2017-04-25 at 2.54.02 PM.png

      The black adjustment of -20 seems to have introduced clipping on the lower part of the branch.

       

      I like the results I get with the auto-white and auto-black adjustments but I think they are doing something other than managing clipping.