Why would I need to shoot the same scene with different exposures?
A general problem in photography is the rendering of scenes presenting very bright highlights and deep shadows. The problem exists with traditional silver halide photography and is more pronounced with slide films. In digital photography, the problem is made even worse as the linear response of the sensors imposes an abrupt limit to the dynamic range captured once the sensor capacity is reached.
This is why you can not get what the human eye is seeing when viewing an HDR scene on common devices. If you capture details in the shadows thanks to long exposure times, you then get blown-out highlights. Conversely, you can capture details in the highlights with short exposure times, but you then loose contrast in the shadows.
Creating an HDR image from differently exposed shots is a way to solve this problem. However, HDR images present a major inconvenience for photography: they can not be displayed correctly on standard computer screens and can even less be reproduced on paper.
What we call Dynamic Range Increase is the process of correctly reproducing the highlights and shadows of a high contrast scene on common monitors and printers. That is, producing a standard 24-bit image that represents the original high dynamic range scene as the human eye has seen it.
What is the added-value of Photomatix?
The process most commonly used for Exposure Blending consists in manipulating the images in image editing softwares such as Photoshop, using multiple-steps masking techniques.
This process is complex, time-consuming and may lead to disappointing results. Moreover, Exposure Blending alone may not be sufficient when the dynamic range of the scene is particularly high. This is why we have designed Photomatix, a software that blends exposures hassle-free and processes High Dynamic Range images with a tone mapping technique that preserves local contrast.
