The Grain section of the Effects tab has controls for simulating film grain for a stylistic effect reminiscent of particular film stocks. You can also use the Grain effect to mask enlargement artifacts when making large prints.
Together, the Size and Roughness controls determine the character of the grain. Check grain at varying zoom levels to ensure that the character appears as desired.
Amount
Controls the amount of grain applied to the image. Drag to the right to increase the amount. Set to zero to disable grain.
Size
Controls grain particle size. Specifying a value of 25% or higher can cause some image blurring.
Roughness
Controls the regularity of the grain. Drag to the left to make the grain more uniform; drag to the right to make the grain more uneven.
-
Crop your image. See Crop images.
-
Highlight Priority
Applies the postcrop vignette while protecting highlight contrast but can lead to color shifts in darkened areas of an image. Appropriate for images with important highlight areas.
-
Midpoint
Higher values restrict the adjustment to the area closer to the corners, lower values apply the adjustment to a larger area away from the corners.
Adobe Camera Raw allows you to easily decrease or increase the amount of haze or fog in a photograph. Click 
in the Adjustment panel on the right to view the Basic panel and adjust the Dehaze slider control.
Amount
Controls the amount of haze in a photograph. Drag to the right to remove haze; drag to the left to add haze.
Radial Filter
Radial filters in Adobe Camera Raw direct attention to specific portions of the image. To know more, see Radial Filter in Camera Raw.
Note: Dehaze is now available as a local adjustment. While working with the Radial Filter, Graduated Filter, or the Adjustment Brush, adjust the Dehaze slider control. For more information, see Make local adjustments in Camera Raw.
Twitter™ and Facebook posts are not covered under the terms of Creative Commons.