HDR Photography: Adjust Brightness and Contrast in Photomatix
To adjust your HDR image’s brightness and contrast in Photomatix Pro after tone-mapping, you use the White Point, Black Point, Luminosity, Gamma, and Strength settings. At this point, you’re just getting the image into the ballpark and making it possible for you to see where you need to make other changes.
Try to keep from blowing out highlights. You’ll have plenty of time to finalize brightness and contrast by the time you’re done.
Control the overall lightness of the image by raising or lowering the White Point, the Black Point, or Luminosity. White Point and Black Point have strong effects on brightness and contrast. Luminosity acts as a shadow control — raising or lowering the brightness in darker regions.
In this example, the image is sufficiently bright. The problem is a bit too much brightness around the front door, in reflections off the floor, and the interior lighting.
This is corrected by lowering the White Point to bring the reflections on the floor and other hot spots under control, raising the Black Point to restore contrast, and then raising the Luminosity to lighten the image.
There is a definite balancing act as you change settings. The amount you choose to change settings has a tremendous impact on the overall appearance of the image. You may push things very hard for an artistic look or nudge things very carefully for a more realistic effect. It’s your call!
Use Gamma as a last resort to control lightness. Raising Gamma tends to reduce contrast too much, resulting in a washed-out look. Lowering it darkens the image and raises contrast. Strength also affects contrast. If needed, return to Strength and readjust.