Above: Final Image made from three exposures below
So here are my three original images I have bracketed. The first one has all your darks or shadows information, the second has all your mid-tones and the third has all your light or highlight information. Contaminating all three will give you more depth and extends your dynamic range to your final image. This is most useful when your have contrast between sky and the land and you have something between them like a mountain or a tree. In this instance you can't use a filter because the skyline Isn't straight, it's been broken up by the object. so this method works great.
So how is this done?
This is done by software, I'm going to be using Adobe Photoshop for this tutorial but this can be done in other software through a similar process.
Step 1. Open all three images in camera raw and do some slight adjustments. Then at the bottom where it says open we are going going to press the little arrow on the side and click object. Photoshop will now open these as smart objects.
Step 2. Put all you images in one file by clicking and dragging or using Ctrl J to copy them.
Step 3. After you have put you images in the same file in the order you want them (usually going from dark to light) we are going to add a vector mask to the first layer. To do that just select your first image and then press the little rectangle icon under the adjustment panel with a circle cut out of it.
Step 4. Then press the eye icon next to your first image you just put the mask on. This will switch the visibility off.
Step 5. Now go to Image > Apply Image and make sure your window looks like mine and click OK .
Step 6. We now switch visibility back on by clicking the eye icon next to your first image again.
Step 7. Repeat to the second layer and we are done.
If we want to make it even better we can add adjustment layers such as curves and hue and saturation to the different layers. We can also double click on layer image and go back into Camera Raw to do some other tweeks (which is one of the benefits of using smart objects).