RAW Files

A Basic Outline and Guide to Understanding and Using 'Camera RAW'

Clive R. Haynes FRPS

RAW Histogram and Exposure Control
Please note image sizes are fairly large to preserve detail, download times may therefore be slow.

The RAW File Reader Dialogue Box - What can it do? How can it help?
Let's open an image and find out what is displayed and the options available.

I've chosen a scene which has a reduced contrast range for this first example.

We start with the image as it opens in the Photoshop CS Browser - shown below

As you can see from the picture above, the RAW image appears in the CS browser together with 'File Properties and other image / metadata, IPTC, Exif, GPS, Camera Raw and Edit History - all accessible by clicking on the appropriate name.
To save space, only opened the File Properties option is illustrated.

The next stage is to open the RAW file selected - see below:
Looking at the shape of the 'Histogram' in the top RH 'box' we observe that the distribution of tones falls a little short of the absolute 'Black Point' and absolute 'White Point'.
The tonality / contrast can be adjusted by moving the Contrast and Exposure slider controls, see below:
Above: Histogram and control settings
before adjustment
Above: Histogram and control settings
after adjusting Contrast and Exposure 'sliders'
to improve the tonal range of the image.
The above example illustrated how the tonal range may be expanded to increase contrast but what about the situation when the contrast is excessive or the whites or shadows (blacks) run off the edge of the Histogram display? In other words, the image is over-exposed or under-exposed. Can anything be done?
Click on the link below.
Click below to Continue


Camera RAW 'Home Page'

Know - How Contents


e-mail CRH Foto