How to brighten an image using Screen blend mode on Curves command in Photoshop CS6 - (Non Destructive)

There are  various ways of changing the brightness of an image.Here we shall discuss the method using Curves command and screen blend mode.This method is non destructive which means that it does not make any changes to the image.
                                         

                                                     Before              After

1) Opening the image in the Photoshop window

Open the image that is underexposed (means the one that needs to be brightened) in Photoshop CS6 by using the menu File > Open or by using the keyboard shortcut Ctrl + O.This will open a dialog box.Select the image by clicking on its name  and click Open button.

2) Selecting the Curves option

After we see the image in Photoshop window we need to open the Curves properties window.For this we need to select the Curves option.There are two ways of selecting the Curves option.

a) Select menu Layer > New Adjustment Layer > Curves...

We can see a dialog box asking the name of the new adjustment layer.By default Photoshop names it Curves 1.If we want we can type in any other name or we can leave it as Curves 1.Click on OK button after naming the layer.

 

b) The other way to get the Curves option is by clicking on the Create new fill or adjustment layer icon (half colored circle) in the bottom of the layers panel on the right side of the photoshop window and selecting Curves option.
                                             

3)Curves Properties panel

Now we can see a Curves Properties panel.We need not make any changes in the curves properties panel.We can click on the double pointing arrow on the top right of the properties panel to exit out of the properties panel.



















 4)Layers panel

We can  see a new Curves adjustment layer with a half colored circle added in the layers panel on the right side of the photoshop window.By default this layer is selected.

                                                     

a) Changing the blend mode

Now we will change the blending mode of this layer from Normal to Screen.For doing this we will click on the up-down pointing arrow in the drop down box on top of the layers panel.By default we see the blending mode set to Normal.As soon as we click on the drop down menu we see a list of blending modes.We will select Screen and find that the image has brightened a bit.If we are happy with the results we can save the image following step 5.

b)Reducing the Opacity

If the image has brightened up too much we need to reduce the Opacity of the Curves adjustment layer.We can see the layer opacity values at the top in the Layers panel right next to blending options.By default we see the opacity set to 100%.When we click on the down pointing arrow we see a slider which we can drag to the left or right to decrease or increase the opacity values.Experiment with the opacity values to get the desired brightness of the image.If we are happy with the results we can save the image following step 5.
                                           

c)Duplicating the layer

If the image needs more brightening we need to duplicate the Curves layer in the layers panel.There are two ways to duplicate the layer . 

First way is to use the keyboard shortcut Ctrl + J .This will place a copy of the curves layer exactly above the curves layer and name it as Curves 1 copy.It will also have screen blending mode .
                                             
Second way is to select the down pointing arrow on the top right corner of the Layers Panel and select Duplicate Layer...option.This will open up a Duplicate Layers dialog box asking us to enter a name for the duplicate layer.By default it will name it as Curves 1 copy.Click on OK button to exit out of the dialog box.

If the image seems to be too bright we can reduce the opacity of Curves 1 copy.
                           

5)Saving the image

After we are satisfied with the adjustments we will save the image by selecting the menu File > Save or by using the keyboard shortcut Ctrl + S.This will open a dialog box where we can write the name of the image.After typing a name click on Save button.