Hazy

Sometimes you get good (or reasonable) lighting. Pictures come out looking like this. Untouched.
A butt shot but you can still tell it is a bird.

Black Naped Oriole 

Or this. Still a bird.

Grey Wagtail

A more common bird.

Pink neck green pigeon (Female)

Or at least a reasonable pose. Zoomed in and cropped.

Pacific Swallow

Or this which is very fortunate. 

And then the rest of the shots have to undergo post-production. 

The raptor looks very soft. The white feathers on the head and chest look like the sky. The fact that the bird was on a tree across a reservoir does not help. 

Brahminy Kite

Without the post-production, you see is the shape. With the changes, you get a clear look at the colour and texture.

Brahminy Kite

Now you can see the eye. 

Oriental Dollarbird

You can see the feathers without squinting. 

Blue-tailed Bee-eater

If everything goes right, I can change the exposure. And you can see the bird but the background looks harsher.

Otherwise, I can go home and then make the changes. It is more of a save than a serious improvement.

Long-tailed Parakeet (Female)

With the ability to make the adjustment on the camera.

As compared above, the sky looks softer. But you can still make out the parakeet's colour.  

Red-breasted Parakeet