Gradating Neutral Density Filter Level 2
1	Open density1.jpg (landscape with faded sky in "desity_filter" folder)
2	Layer > New Fill Layer > Gradient... and click OK
3	Choose Black to Transparent, and check Reverse box, and click OK
4	Select Soft Light from the layers blending mode
	Note that Fill Layer automatically creates  a mask.
5	To reverse applied effect selectively, use soft Brush Tool with low opacity (25%)
	File > Revert
	Ctrl > Z, Z, Z to examine the difference