Blending two exposures

Blending exposures is rather a new development in photography that has become popular since digital SLRs were made available to the average consumer. The reason is that with landscapes and shooting twilight or sunsets the there is often a large dynamic range (the difference in brightness between areas). So, to capture an image one has to compensate and cheat the light between areas. Made simply the foreground is much darker than the sky. What we see with our eyes is not what is physically there. Our eyes adjust but film or a sensor does not.

Balancing an exposure in film days was possible with the use of a graduated filter. A filter that is dark at the top and normal at the bottom and in the middle it graduates between the dark and normal. The purpose of this tutorial is to mimic the graduated filter using two separate exposures and blending them using layers and masks.

With all my tutorials the first thing to remember is get everything right in field. Compose and plan properly and every thing will be much easier in the digital darkroom. All my tutorial will be done in adobe photoshop cs 3. If you are serious about landscape photography then unfortunately photoshop elements is not going to do the trick. Rather get an older version of photoshop than elements. In my opinion elements only gives you a taste of what you can do with photoshop. Even GYMP (free open-source software) is better than elements.

So let’s start

Here is an example two exposures. The first exposure was taken to hold back the sky. The second was to expose the fg. As I wanted the water to paint silky streaks I planned the exposure around the foreground. This was 1/5th of a second. The sky was 1/30th of a second. That is a dynamic range of 2 and half stops.

After I have converted the raw images open both of them in photoshop. By using the ‘move’ tool’ hold ‘shift’ and drag the darker exposure over the lighter one. You now have one image with two different layers in it.

Make sure the top layer is selected and add a layer mask. This can be done by clicking ‘add layer mask’ in your layers pallet. Or in your menu you can go layer>layer mask> reveal all.
Masks allow you to hide part of a layer. By painting black on a mask you can hide past of a layer. White means everything is visible. Anything in between ie grey will the opacity of the pixel. Dark grey will hide most of the layer, light grey will hide only a small amount.

Now that you have a mask on your dark layer. Select the gradient fill tool (under the paint brush). With your mask selected make sure you have the colours black & white selected. If white is your foreground colour and the gradient tool selected hold’ shift’ and drag from top to bottom. This will reveal the bottom layer. Your results should look like this.

With the top layer being slightly too dark select the layer opacity on the top layer and drop it to around 80%. This will lighten the dark sky a bit.

You now have a balanced exposure that would be believable to the eye.

Apply some adjustments and your result is ready.