Exposure Tolerance – RAW and JPG in Comparison

The image quality of digital photos depends on the file format and compression rate. The chosen format also determines the correction possibilities. This article illustrates the differences between RAW and JPG images using examples of exposure, i.e. exposure tolerance.

This photo was captured in the shadows of a house. The camera automatically stored a file in RAW format as well as in JPG format. The exposure was chosen in order to ensure optimal exposure of the person in the foreground of the image. The mosaic tiles in the background are lit by direct sunlight. The high contrast in brightness between the sunlit and shadow areas can very quickly be too difficult for a digital camera to process correctly. The following image shows an uncorrected image in JPG format mode with the right exposure. 

Aufnahme mit JPG

Image in JPG format

The over and underexposure warning highlights the image areas that are outside of the contrast capturing range and that cannot be fixed in a photo editing program, as there is no information available about these areas.

Aufnahme mit JPG - Über- und Unterbelichtungswarnung [Photoshop Elements 7]

Image in JPG format – Over and underexposure warning [Photoshop Elements]

Alternatively, images captured in RAW format mode can be corrected much more extensively as it has a much wider contrast range. Because the camera manufacturers each use their own RAW formats, these formats have to be converted into the established formats in order for the photo editing programs or other programs to able to open or run these format files. There is a wide range of programs to convert these files (RAW converter). In Photoshop Elements the camera RAW module is responsible for this procedure. It is activated automatically when RAW photo is opened.

The following image shows the previous example photo as a RAW file. The untouched photo bears the same over and underexposure problems as the JPG photo. The histogram also alludes to the problems.

Unkorrigiertes Foto mit Über- und Unterbelichtungswarnung in Camera RAW 5.4 [Photoshop Elements 7]

Untouched photo with over and underexposure warning in Camera RAW 5.4 [Photoshop Elements]

In the following image, numerous correction tools have been used. The deciding correction edit was made using the “repair” button. This allows image information to become visible that can be found in the RAW format mode but not in the JPG format. The overexposed image areas can then be fully corrected.

Korrigiertes Foto mit Über- und Unterbelichtungswarnung in Camera RAW 5.4 [Photoshop Elements 7]

Corrected photo with over and underexposure warning in Camera RAW 5.4 [Photoshop Elements]

Which photo is better is not up for discussion. The result achieved by correcting the image is reminiscent of an HDR image. The important thing is that RAW format provides the option to correct and edit an image, so mistakes can potentially be rectified with the right software.

The two following images show both versions of the photo using curve (tonality) correction tools. The histograms emphasises again how effective the correction tools are in RAW format. The JPG image displays a histogram that is chopped off on the right and left side. The edited RAW image’s histogram is well within the illustrated area and is not chopped off at all.

JPG-Aufnahme und Histogramm [Photoshop Elements 7]

JPG image and histogram [Photoshop Elements]

RAW-Aufnahme - Korrigiertes Foto und Histogramm [Photoshop Elements 7]

RAW image – Corrected photo and histogram [Photoshop Elements]
You are here: Home Exposure / Exposure metering Exposure tolerance – RAW vs JPG