I am often asked what's involved with the post production of the Architectural Photography I do and while this is kind of like asking how long is a piece of string here is a rough break down of how it works.
There are 2 main things your eyes can do that a camera by itself can not.
1... Light Range. Your eyes and brain are very good at seeing a huge light range, on the darkest night you can make out silhouettes and shapes and on the brightest days you squint but can still see. A single photo from any camera has a much more limited range between what it sees as totally white and totally black.
2... White Balance. Your brain is very good at tricking you into thinking something is the color that it is. Cameras record a color and that's it.
For example, if you hold a piece of plain A4 office paper under a standard tungsten light bulb your brain tells you it is white but a camera sees orangey-red. This is because your brain knows office paper is white and overrides the information your eyes are receiving.
This is called White Balance and the below link, while technically not about White Balance, is an interesting example of how your brain tricks you.
So a photographer has to allow for Light Range and White Balance when shooting and often these are used as artistic tools to create a particular look or feel. However, it is usually the goal of Architectural Photography to get as close to reality (ie what we are used to seeing) as possible.
The best way to explain this is by showing...
Above is a photo straight out of the camera of a Pool that I shot recently for Neptune Pools. It shows both of the above problems cameras have. The lights inside and around the house are tungsten and therefore have come out all red/orange AND in order to expose the lights correctly all the dark bits have lost detail and gone black (under exposed).
I order to get the detail back in the dark areas I took another photo with different settings, however, this has left the bright bits too bright (over exposed).
So when I am shooting this type of job I make several different exposures all with different settings and with additional lighting and then blend them together in Photoshop. Below, you can see 6 different exposures with different settings that take into account Light Range and White Balance.
There are a bunch of different ways and tricks to blend the images together and it depends on a lot of things as to how I do it from job to job. The basic idea is to layer the images on top of each other and then erase away the bits you don't want to see which shows the bits you do want to see on the lower layer.
Above is an example of a layer that has the brighter bits erased, the checker pattern is transparent which means a lower layer would show through in these places.
This is just a very basic example of how to do it, there are many different ways of selecting the bits you want to keep and getting rid of bits. In reality the workflow on every image is slightly different depending on the situation.
Below is the finished image, it is a blend of 6 different exposures and numerous other adjustments in certain areas. It is just one of 10 images supplied to the client for this job and all of them were edited in a similar way to this.
Hopefully this gives you a rough idea of how an image is processed. .. it is obviously a lot more detailed than just pointing the camera in the right direction!