What causes the blue glow and edge distortion around bright objects in my photo?

Asked 7/18/2012

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I tested a Tamron 28-70mm f/3.5-4.5 macro lens on a Sony NEX-C3 and noticed a bright bluish haze around high-contrast bright areas, such as a white water bottle, parts of the bike frame, and a white shirt against a darker background. There also seems to be some odd distortion in the background near the bicycle seat. The lens was used wide open or close to it. Is this caused by too much light reaching the sensor, by using the lens at a wide aperture, or by the lens quality/design? Does the fact that it is labeled "macro" matter here?

Originally by Photography Stack Exchange contributor. Source · Licensed CC BY-SA 4.0

Photography Stack Exchange contributor

14y ago

2 Answers

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These are known as Chromatic Aberrations or Colour Fringing. These predominantly occur around areas with high contrast such as sharp edges in photographs or around the white water bottle and dark background in your case.

A wider apeture can affect the lenses sensitivity to aberrations although certain lenses can see this "effect" vary depending on focal lengh and this is more often caused by very slight imperfections in a lens.

Don't worry, even more expensive lenses can suffer from this anomally. The lens surface has varying levels of maginification across its surface so you may notice that this anomally is more prominent toward the edges of the lens/photo.

These can be corrected very successully with software (Such as Adobe Lightroom/Photoshop) and overall should not pose much of a problem except for slight reduced sharpness around high contrast edges. 35AUD was a great buy!

Further reading : http://www.dpreview.com/learn/?/Glossary/Optical/chromatic_aberration_01.htm

How to correct/prevent the problem: http://www.tutorial9.net/tutorials/photography-tutorials/correcting-and-preventing-chromatic-aberration/

Originally by user10105. Source · Licensed CC BY-SA 4.0

user10105

14y ago

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AI Answer

Generated from our catalog & community — verify before relying on it.

This looks like chromatic aberration (also called color fringing). It commonly appears along high-contrast edges, especially around bright subjects against darker backgrounds, and can show up as blue/purple/green fringes or a glow.

It is not simply "too much light hitting the sensor." Wide apertures can make aberrations more visible, and some lenses show it more at certain focal lengths or toward the edges of the frame. Lens design and optical imperfections are the main cause, and cheaper lenses may show it more clearly, but even expensive lenses can have some.

The background issue you mention is also likely related to lens aberrations/optical rendering rather than the lens being marked "macro." A macro-capable lens can still be used for normal scenes; the macro label itself is not the cause.

The good news is that chromatic aberration is often corrected very well in software such as Lightroom or Photoshop, so it usually isn’t a major problem unless it is severe.

UniqueBot

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14y ago

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