Properly Exposing With Layer Masks in Photoshop

Layer masking... layer masking is an incredibly handy thing to know, for every photographer. Layer masking can be used well for many things but what I will cover is using it to properly expose an scene with unbalanced lighting. this requires you take at least two photos of the same scene with your camera in the very same place, so this requires a tripod.

I will be using this shot of my backyard for the example. which has incredibly harsh shadows while the sky and clouds are nicly lit and colored by the sunset.. so this would require a graduated ND filter...... or... layer masking in photoshop.. much cheaper

AS you can see The top image is properly exposed for the sky and the bottom image is properly exposed for the back yard (all the greenery) its a bit over exposed but not too bad.

So this technique of layer masking requires photoshop I am using CS5 but it is the same process for the older versions.

1. load your images into PS

2. Drag the images into the same document so that they are both 2 separate layers

3. So first make sure that you take note of which image is on top of which. Then apply a layer mask to the top layer. to do that you will click the tiny button in the bottom right hand corner which has a white circle inside a grey square, located to the right of the button which says "FX"

 

Its kinda hard to find so here's a screenshot of it..

4. once you have clicked that a layermask will be applied you will be able to see it appear in the layers window to the very right of the layer you applied it to.. does that make sense i have a screenshot showing what it looks like a little later on.

5. So heres the key part, which takes some patience and careful movement of the paint brush tool. so select the paint brush tool and make sure the top layer with he mask is selected. set the color of the brush to black, and paint over the part of the image which is not correctly exposed. the black paintbrush will act as an eraser and erase what you paint revealing the image below. so only paint what is not correctly exposed on the top image, but is on the bottom layer.. this is probably super confusing the way im explaining it, but heres a screenshot. you can see in the layer mask all that black against the white background is the part which i have painted over.

So this is a screenshot of the image after i had applied the layer mask and used the black paint brush to reveal all the properly exposed foreground which is much under exposed in the original top image.


6. once you have painted all that you need to, to touch up I recommend setting the brush opacity at 30 - 40 and a fairly small brush size and painting around the edges of the part which you just painted.. this allows for a smoother and cleaner transition of colors and light in the image.

FINAL IMAGE.. i didn't not the best job of painting on the layer mask, but you get the point...

If you have ever seen images which are black and white with a single colored part to it... this is the answer to how that's done. all you need to do is duplicate your layer by right clicking the layer in the layers window and clicking duplicate layer.. then change the top layer to greyscale, then paint in black over which ever part you would like to be in color.. boom done. pretty simple. Once you get this down it can have so many uses, and its not cheating by any means its just compensating for natures way of providing unbalanced light in such scenes...