A bokeh image (japanese term) is a picture with a blurred background which highlights the subject in a inimitable way.
The bokeh effect is due to a narrow depth of field. It is necessary to use a large aperture lens and a image sensor as large as possible to achieve this effect. It is impossible to get a bokeh effect with a compact camera, it is very difficult with an DSLR (even with a full frame sensor), and the result is convincing only with a long focal length and a very open diaphragm. A face portrait is then possible but a full-length portrait remains impossible. In practice, it would use a very large format camera with a large aperture lens to achieve a full-length portrait with interesting bokeh effect .
There is another solution:
It consists in simulating the optical conditions of a large format camera with a matrix of stitched images.
From an optical point of view, the result is completely equivalent to a very large format camera equipped with a short focal length and a large aperture. The size of the image allows very large posters. But there are several difficulties to use this approach, that is the reason why it is not frequently used. Shooting is indeed very tedious, it must achieve at least a dozen photographs and if the subject is a character, you must chain them quickly. The positioning of the camera is also problematic because the angles are narrow and the positions of each image must be accurate.
In addition, some images will be blurry (that is the principle of bokeh) and the stitching could be hard, even with a software like Autopano. Indeed, the absence of stitching points in these images can not be completely compensated by algorithms and it will be necessary to place these pictures manually, which can takes a considerable time.
Note : This method is also called Brenizer method, as Mr Brenizer is a photographer from New-York which used this method to make great pictures.
The PanoMachine overcomes these difficulties because it provides a solution to each of these problems:
- It automatically controls the process of shooting accurately and quickly.
- It generates an XML file for each process, which records the spatial coordinates of each image , making stitching process automatic and errorless.