STEP 4
Go to Layer>New Adjustment Layer>Levels. Change the levels to 0, 1, 204 as shown below.
Now we are going to stack all the layer onto a layer. Press Ctrl+Shift+Alt+E/Cmd+Shift+Opt+E to stack all the layer onto a new layer. Rename the layer with “Stack”. This layer is basically a combination of all the layers.
