Turn out the lights on a daytime scene using the power of Photoshop’s adjustment layers
Go to File>Open and choose the file you want to edit. Go to Layer>New Adjustment Layer>Brightness And Contrast. Set the Brightness to -150 and the Contrast to -50. Next, go to Layer>New Adjustment Layer>Levels. Set the Highlight Output level to 100.
Because we have darkened the image to simulate the night, we’ll also need to reduce the saturation. Go to Layer>New Adjustment Layer>Hue/ Saturation and set the Saturation to -60. Select the Red channel and set the Saturation to -60. Finally, select the Blue channel and set the Saturation to -40.
Turn off the adjustment layers and select the background layer. Go to Select>Colour range. Click once in the sky to select the Blue and set the Fuzziness to 80, then click OK. Go to Select>Save Selection and name this selection ‘Sky’. Turn the adjustment layers back on.
Go to File>Place Embedded and select a stock image of some stars. Resize and position the stars over the sky and to go Select>Load Selection. In the channel menu choose the Sky channel. Go to Layer>Layer Mask>Reveal selection. Select a soft brush and clean up the mask.
Go to File>Place Embedded and select a stock image of the moon. Resize and position the moon behind the buildings. Hit Opt/Alt, click on the stars layer mask and drag up to the moon layer to copy it. Set the blend mode to Screen and see the mask of stars from behind the moon.
Create a another new layer and name this layer ‘Street lights glow’. Set the blend mode to Color Dodge. Choose a dark yellow or orange colour and with a soft brush, paint the glow onto the street. Duplicate this layer to make the glow stronger.
Once again, create a new layer and name this layer ‘Street lights details’. Using the same method as the previous step, paint small details onto the edges of the signposts and buildings, anywhere where the light from the street lights would shine on the objects in the street.
Go to Layer>New Fill Layer>Solid colour. Set blend mode to Color Dodge, choose a colour – we used #888273. Invert the layer mask (Cmd/Ctrl+I) and paint one of the windows black. Duplicate layer (Cmd/ Ctrl+J), select the layer mask. Go to Gaussian Blur and set Radius to 10.
Repeat step 9 on a number of windows. Try to vary the colour from window to window. You can also vary the blur amount and even paint in the glow yourself, using a soft brush on the colour fill’s layer mask.
Go to File>Place Embedded and choose an image of some white car lights. Resize and position the lights on the left side of the road and set the blend mode to Screen. Go to Layer>Layer Mask>Hide all. Now with a soft white brush, paint the lights back in and fade them out in the distance.
Duplicate the white car lights layer. Go to Filter>Blur>Gaussian Blur and set the amount to 10px. Go to File>Place Embedded and choose an image of some red car lights. Resize and position this layer on the right side of the road and set the blend mode again to Screen.
Go to Filter>Liquify (for Elements go to Filter>Distort>Liquify). Warp and distort the red lights to match the road. Go to Layer>Layer Mask>Hide all and with a soft white brush, paint the red light back in.
Go to Layer>New Adjustment Layer>Levels. Set the Shadow Input level to 35, this will help the lights blend in more. Go to Layer>Create Clipping Mask (Opt/Alt+Cmd/Ctrl+G) so it only affects the car lights layer.
Go to the Hue/Saturation settings, set Saturation to -20. Create a new Clipping Mask. Duplicate the red lights and adjustment layers (Cmd/Ctrl+J), reapply the clipping mask if needed. Select the red lights layer, go to Gaussian Blur, set Radius to 10.
Create a new layer (Shift+Cmd/Ctrl+N) and name it Noise. In the mode box select Soft Light and tick the box to fill the layer with 50% Gray. Go to Filter >Noise>Add noise, enter 3%. Go to Layer>New Adjustment Layer>Level, select the Blue channel and enter 10 in the Shadow Output Level.
Select the first adjustment layer that is above the background layer and Shift click the top layer to select all of the them together. Select Layer>Group Layers (Cmd/Ctrl+G). Then go to Layer>Layer Mask>Reveal all. Select the Gradient tool and painting from black to white, add a Gradient to the layer mask and finish off the effect.