Thanks for the scoop John,

--
Cheers Wendy

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John - Pa. wrote:
This is a common photographic artifact, often called "Purple
Fringing", and it is usually caused by a technical effect called
"Chromatic Aberration". CA is a function of the lens and according to
Wikipedia, CA is caused by different wavelengths of light having
slightly different focus points as they pass through the lens
elements.

High-tech (read; "expensive") lenses can minimize CA with special
materials and construction, but this is one reason why two lenses of
the same focal length can differ in cost by 2-3-times.

Short of buying new super-duper lenses, Wikipedia says;

Commonly advocated methods of avoiding purple fringing include:
- avoid shooting with a wide-open lens in high contrast scenes;
- avoid overexposing highlights (e.g., specular reflections and
bright sky behind dark objects);
- shoot with a Haze-2A or other strong UV-cut filter.

Post-processing to remove purple fringing (or chromatic aberration in
general) usually involves scaling the fringed colour channel, or
subtracting some of a scaled version of the blue channel.


JD



On Sun, 26 Nov 2006 07:37:03 -0800, "wendy7" wrote:

What causes the blue around the edges. Is it a problem
with the camera, a Sony or the photographer?
It happens a lot if the camera is pointed towards bright light?