Color Histogram

Have learn a lesson today about histogram. If you are shooting picture of flower which drive one of the color channel over, it should be considered as normal and do not try to reduce exposure to bring the over channel back in range. But doing so, it will bring to other two channels to seriously underexposure. And detail information of the color which drive the over channel will be lost.

The lesson is although you need to prevent overepxosure in digital shooting, you need to excerse this in context.

The following photographs and corresponding histogram is used to illustrate my point here:


1. The photograph I have taken with -1 EV exposure compensation. Note that the red channel is not overexposed.







2. This one is obtained with +0.5EV from RAW to JPG conversion. Note the red channel starts to have overexposure show in the histogram.







3. The final one is obtained with +1 EV from RAW to JPG conversion. Note the red channel is shown clearly with overexposure from the histogram. But at the same time the information contained in both green and blue channel increased considerably.






Histogram explained in Luminous Landscape:
http://www.luminous-landscape.com/tutorials/understanding-series/understanding-histograms.shtml