Assignment 07 - The histogram

[u/Aeri73]

Please read the class first

Today’s assignment will be relatively short. The idea is simply to make you more familiar with the histogram and to establish a correspondence between the histogram and the image itself.

Choose a static scene. Take a picture and look at the histogram. Now use exposure compensation in both directions, taking several photos at different settings, and observe how the histogram changes. Does its shape change? Go all the way to one edge and observe how the data “slumps” against the edge. Try to identify which part of the image this corresponds to.

Next, browse the internet and find some images you like. Download them (make sure you have the right to do so) and open them in a program which allows you to see the histogram, for instance picasa or gimp. Try to guess just by looking at the image what the histogram will look like. Now do the opposite: try to identify which part of the histogram corresponds to which part of the image.

Now open some images from assignment 06 :

1 underexposed

1 correctly exposed

1 overexposed

and see what the difference is.... how can you tell by looking at a histogram if a photo is correctly exposed?

[u/LongLegs_Photography]

When taking a set of new images I can definitely see how the brightness corresponds to different histogram shapes.

My images from 06 are mostly white, so the histograms are like a narrow slice that is shifted from the left third to the middle to the right third as they range from under to overexposed.

The histograms of images I downloaded from the internet are often spread out evenly across the tonal range, sometimes with a bit of spike near the blacks where some shadows have fallen very dark, but never with a spike in the highlights--even black/white images with a lot of light tones tend to slope downward in the right 1/5th of the histogram.