Ever taken a shot that came out like this... 
Normally I would have a little curse at my foolishness and bin it but...
just to show that not all is lost.....
.
Normally I would have a little curse at my foolishness and bin it but...
just to show that not all is lost.....
.
[b]Well all is not entirely lost. With a few clicks you could retrieve most of the detail.
Not perfect by any means and it won't win you any prizes but its acceptable for say a personal album
Load the underexposed image...
Duplicate the layer via right click on the layer.
Change the blend mode to screen
Right click and duplicate that layer
Repeat for another 4 layers.
Merge all flatten.
Now you can see some difference crop as required.
Duplicate layer again.
Again apply a screen blend
Now a little play with the levels..just push the diagonal line towards the top left corner slightly.
Now a touch of saturation...value around 9
Finish off with High pass Sharpen...value around 4/5
