Combining Indoor and Outdoor Lighting
Photoshop CS6 Tutorial
How to Combine Images With Indoor and Outdoor Lighting in Photoshop
Often times in architectural photography the interior and exterior lighting have different intensities and color temperatures. If you adjust the camera for the interior, then the light through the windows is overexposed.
With your camera on a tripod, take multiple images of a building interior. Keep the focus and aperture settings the same. Adjust your exposure by varying the shutter speed.
In Photoshop, open two of your images (File > Open) and combine them into one multi-layer document.
Use the Move tool and hold the Shift key as you drag the image to the destination document to align the layers.
With the lighter image on top, you will want to use the exterior from the lower image. Select the upper image layer and click the Add Layer Mask button to add a white mask.
The Layer Mask is a grayscale image where white areas are opaque and black areas are transparent. Select the Paint Brush tool and click the layer mask.
Set the Paint Brush color to black and lower the brush opacity.
Paint the areas of the mask inside the window and the lower, properly exposed exterior appears.
Masking with the Pen Tool
This can also be accomplished by using the Pen tool to define the path. Convert the path to a selection and fill the area with black (Edit > Fill + Black).
Generally the outside light is one temperature and the inside light is a different temperature. For instance, the outside light may be daylight (5500k) and the inside tungsten (3200k). By combining images in this manner, you can balance each image for the appropriate light and then combine them into one composite. This is similar to how your eyes view the scene.