Photorealistic rendering

Photorealistic renderings are the most commonly used, the final effect is the same as a good photo.
This is the best way to show a product that has not yet been created or to test different solutions and have a look at what will be the final effect in real life.
Normaly photorealistic renderings are the most time-consuming since much more work is needed to have very realistic materials, textures and a lot of CPU time to have the best possible illumination.

With photorealistc renderings it's also possible to insert the 3d rendered object inside a photo. This process, widely used in architectural renderings, gives an even more reliastic effect.
This particular kind of renderings are also the most commonly used for brochures, website presentations and catalogs.