14 votes
Accepted

What is the blue halo around objects when using a teleconverter?

The blue halo is often referred to as purple fringing. It is caused by chromatic aberration. According to Wikipedia: There are two types of chromatic aberration: axial (longitudinal), and ...
xiota's user avatar
  • 27k
5 votes

How to prevent colour noise from developing in water portion of the image?

Really, the only true 'fix' for this is to not bang the colours quite so hard in the first place… or, I suppose, to have used a polarising filter to kill the majority of the reflections before they ...
Tetsujin's user avatar
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4 votes

How can I avoid those pink/purple lines in my portrait photos?

As established in comments, it's chromatic aberration, specifically purple fringing which you see mostly at high contrast edges in out of focus areas. You can mitigate it by closing down the aperture ...
Tetsujin's user avatar
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3 votes
Accepted

What causes blue and red gradient/shade around black spots in photos?

The term is chromatic aberration. Is is explained in detail here: What is Chromatic Aberration?
Rene's user avatar
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2 votes

What is the blue halo around objects when using a teleconverter?

As you know, the job of the lens is to project an image of the outside world onto the surface of the camera’s image senor (or film). As the light waves from the vista traverse the glass lens, the ...
Alan Marcus's user avatar
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2 votes

How can I avoid those pink/purple lines in my portrait photos?

The camera lens projects an image of the outside world onto the surface of the camera’s image sensor. During the exposure, this image is recorded. Mostly these images are tiny however image size is ...
Alan Marcus's user avatar
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1 vote

How to prevent colour noise from developing in water portion of the image?

what can I do to avoid it: The general answer is to use selective edits to affect only the desired areas, rather than global "slider" adjustments.
Steven Kersting's user avatar

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