Black and White & Creative Image Editing in Lightroom - Black and White in Photoshop CS4 and Photoshop Lightroom - page 181

a. In order to brighten areas: increase the Exposure and Brightness
amounts (I like to start with + 2.00 for Exposure, and Brightness to +50
but the specii c settings will vary from image to image).
b. To darken areas: decrease the Exposure and Brightness amounts
(200 Exposure, 50 Brightness).
4. Choose the size of the brush according to the area you wish to adjust.
The size specii es the diameter of the brush tip in pixels.
5. Set the Feather amount on a higher setting - this creates a soft-edged
transition between the brushed area and the surrounding pixels.
I usually start at +100 for a soft brush, and make the edges harder when
necessary by decreasing the Feather amount. If the Feather amount is
greater than zero, the brush cursor appears as two concentric circles.
The distance between the inner and outer circle represents the Feather
amount.
6. Choose a low Flow amount - this controls the rate of application of the
adjustment so that you can build the dodging or burning incrementally
with successive brush strokes. This allows you to make some areas more
dense and some softer as you brush. I usually begin with a Flow of 20,
although you will need to increase this amount for stronger results, and