Here's a simple challenge.
The difficult part is finding a badly exposed image

The first image, 050, shows an image whose lighting fooled the camera.
The white foreground fooled the camera causing it to under expose the people!
Next image, #048, shows how easy Qimage Ultimate makes it to repair the exposure.

Use the mouse and draw a box around one of the darker faces from the back row.
I chose the man all the way to the right side, back row.
You can see the blue box around his head. (After you draw the box, you will be given a choice of Blue, Red or Magenta check boxes. Select the Blue) (Blue is normal exposure adjustment)
Then I reduced the Fill light by three ticks to even it between the front and rear rows.

No sliders needed.
No Luminance, no Opulence, No Flatulence ...
Hint,,, when drawing the box, include more dark areas to cause the exposure to increase.  Include more light area to cause the exposure to decrease.

Try it a few times, varying the size and location of the box. You will be an expert withing 10 minutes!!
053 is the image with the refine screen closed and after good advice from Terry, the eye shattering white distraction is cropped out.

Have fun!
Fred

Last resort; switch from Boxers to Briefs.

Fred