What is a photo composite? The dictionary definition of a composite is
“com • pos • ite
[kuhm-poz-it] Show IPA adjective, noun, verb, com • pos • it • ed, com • pos • it • ing.
made up of disparate or separate parts or elements; compound: a composite drawing; a composite philosophy. ”
In plain terms a photo composite is an image made up of more than one photo, the idea however is to make it look like it is one single photo and not a collection of images put together.
So why not just take a single photo then?
The reason for photographers creating photo composites is because it gives them such a broader range to work with. For instance a photographer could take a photograph of a model in a studio and then put her / him in any location in the world. Something which may not be possible if the photographer did not have the budget to fly a whole creative team to another country. Another benefit of photographing a model separately to a location is, when photographing out on location it's impossible to get a broad range of tonality from detail in shadows and detail in highlights without taking multiple exposures. If you just took a single shot then something would have to be sacrificed, either your highlights would get blown out (no detail, just pure white), your shadows would be too dark almost black or you would have some details in both the shadow and highlights but it would look pretty flat overall.
So as I just mentioned you would have to take multiple exposures, now if you try to take a photograph 3 or more times with a model standing there, I guarantee that your model would have moved in each shot even if it's just millimeters. Therefore if you take your location shots first and then take photographs of your model you can composite them together later on during editing and have an image with an amazing range of tonality through. Just look at images by photographers such as Erik Almas, Joel Grimes or David Hill, all great photographers who create incredible photo composites. You may have seen their work before and just not realized their images were made up of composites. Creating photo composites can allow photographers to achieve results in their final image that may not otherwise be possible from just a single photo.
How would you create a composite?
Creating a photo composite is not an easy thing to do, there's so many different ways and techniques from simply putting a model into a location, to making something float or more intricately stitching together multiple photos with varying exposures to create mind-blowing High Dynamic Range images. In short because to create a basic photo of say a model with a location background that contained also contained a large tonal range, firstly you would have to take 3 or more photos of just the background. One photo would contain the detail in the shadows, another containing detail in the highlights and a 3rd image with a correct exposure. (This can be achieved through bracketing). You would then merge the 3 images together when editing later on.
The photo of the model could then be taken either in a studio or at the same location as your background image (which would enable you to match the colors and tonality as closely as possible naturally). Once you had created your background image you would then put your model into that image by using something like the mask tool. After you've com-posed your photos together you then need to alter things like the hue / saturation and color levels to ensure the color range of your model matched that of your background. For example if your background had a cold cast to it but your model had a warm cast, then your viewers would know straight away that something about the photo was not right even if they did not know exactly what it was.
One of the great things about photo composites is that you can take your background images anytime, anywhere and then put your model in afterwards. This means you can build up a collection of background images to use when needed, without going out and searching for a location.