Landscape photography is all about capturing detail throughout the scene, and to do this you need to get exposure right. But in most cases where a sky is included, the land will be darker than the sky, especially if you’re shooting at dawn or dusk. To get the best results you need to balance the light, either by using a graduated filter or by exposing multiple frames for different parts of the scene so that you can later blend two photos in Photoshop.
Traditional photographers have long been able to create two exposures on a single piece of film. This technique is now also easily achieved digitally - overlaying images using a ‘multiply’ or transparency filter, for example. This example shows how the integration of two different scenes can help to strengthen the ideas communicated within an artwork.