Left Column

The Histogram

To properly "enhance" or "improve" a photograph, we need to FIRST take the "best" possible exposure with the "best" white balance. But, sometimes you only can get close.

Real Time Camera Histogram in Record Mode


Recorded Histogram in Display mode


Most cameras can display or record histograms

When your camera does a meter reading, it is trying to determine what is mid-gray (18% gray), the dynamic range, in the scene being recorded by the sensor.

If you plot horizontally the brightness (luminosity) levels from black at the left (0) to brightest at the right (white - at 255), in 256 steps from black to white Vs, Vertically, the number of pixels at each luminosity step you get a graph called an Histogram.

"There is no such thing as a bad histogram." it is just a way to tell you how the light is distributed across the recorded photograph!

histogramThe Vertical Axis shows the number of pixels recorded at each level (step) of brightness.
The Horizontal axis has a scale of 0 - 255 (left to right) with 0 = black and 255 = white. Mid gray has a value of 128.

clip1Today, cameras display a pictures histogram in playback mode, or in "live" record mode. Though there is no such thing as a "good" or "bad" histogram, generally, a picture with an histogram that shows most of the pixels in the middle is better exposed than one that has the pixels clumped towards the black or white end of the graph.

In the thumbnail of the photo the camera is indicating with flashing that some pixels are Clipped!

histogram-normal02 Normal Histogram
histogram-under01 Under exposed Histogram
histogram-over03 Over exposed Histogram

With a little practice, you will be able to tell if your photo has good exposure values by looking at just its histogram, not the displayed image on the cameras screen.

So, what's the point? What do we need to really know here?

Theoretically To capture The "Perfect Picture" you need...

It turns out that if you over expose beyond 255, around 2 stops, inother words exposr to the right... you can recover the clipped information, which can dramatically improve the photograph...