Sigma C72900 User Manual

 

The histogram is a graph depicting the distribution of brightness values 
in the image for each of the three color channels (Red, Green, and 
Blue) (The histogram displayed in the Shooting Mode is the distribution 
of tones in the image). The horizontal axis shows the brightness level, 
with darker pixels towards the left side and brighter pixels toward the 
right. The vertical axis shows the proportion of pixels at each level of 
brightness. 

 
By examining the histogram of the full image, you can gauge the overall 
exposure of that image.  You can also use the histogram to determine if 
zoomed-in sections of an image are over or under exposed. 
 

This histogram shows that the higher pixel 
values are never used in the image, 
indicating that the image is underexposed, 
and therefore will appear dark. In general, 
when the histogram is higher on the left side, 
the image is mostly composed of dark 
pixels, causing it to appear dark—either 
because the image is underexposed or 
because it is a dark scene such as night 
shot or sunset.

 

 

 

 

This histogram shows a fairly even 
distribution of pixel values, indicating that 
the image is well exposed, with good 
contrast. However, the histogram 
distribution of a well exposed image will 
vary greatly depending on the subject. 
 
 
This histogram shows that many of the pixel 
values are at their brightness limit, 
indicating that some areas of the image 
may be blown out. In general, when the 
histogram runs off the right side, the image 
will have many white pixels—either because 
the image is overexposed or because it is a 
bright scene such as the beach or snow.