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Old Apr 11, 2010, 5:54 AM   #1
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In this picture there's some kind of light artifact slightly right of center.
http://www.g7welcomingcommittee.com/...gon1_plane.jpg

Can anybody tell me the technical name of the phenomenon? Is it called "Lens flare", or something else?.
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Old Apr 11, 2010, 8:21 AM   #2
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Anytime you have a light source that bright (or light reflecting from a bright object), that light can be reflected between optical elements and cause flare and ghosts (where you see the same light source appear in other portions of the frame), as well as loss of contrast from veiling flare. The large, lighter spot to the left of center on the larger portion of the mountain in the scene is also a result of flare.

Use of protective filters can often cause it to be much worse (especially inexpensive filters with poor optical coatings).

Here's an article discussing how some filters stack up, where you can see flare in a number of them:

http://www.lenstip.com/113.1-article...ters_test.html

For example, this Tiffen is particularly bad:

http://www.lenstip.com/113.24-articl...n_72mm_UV.html

Here's a wikipedia article on Len flare:

http://en.wikipedia.org/wiki/Lens_flare

Lens quality (and the quality of the coatings on their optical elements) also makes a big difference in flare resistance.
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Old Apr 11, 2010, 3:25 PM   #3
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Part of the reason for this, and what many, even fairly experienced photographers fail to take into account, is that the sun or other bright light source, can cause reflections within the lens elements, even when the source itself is outside the frame of the picture, The reason becomes obvious when one thinks about the fact that the lens is round, while the sensor or film is rectangular.
Usually, the first reflection will be the sharpest, and brightest, diagonally opposite the light source. Further reflections become increasingly out of focus, dimmer, and may show up anywhere in the frame. This depends a lot on the type of lens and number of lens elements involved.
As the old advice goes, and is still valid: don't shoot into the sun.

brian
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Old Apr 13, 2010, 3:37 AM   #4
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Thank you very much. I'm discussing this photo and a few others on this thread.
http://www.unexplained-mysteries.com...owtopic=179829

Most of the analyses are on page four.

Here's something else on which I'd like some help.

There are two analyses of this picture.
http://www.clavius.org/img/bootspot.jpg

Both analysts seem to have good credential but they've come to opposite conclusions.
http://www.youtube.com/watch?gl=ES&hl=es&v=A6MvcIs4OcQ
http://www.clavius.org/bootspot.html

Can anyone comment on this. I intend to post this thread on a thread where this is being discussed. I'm also asking about this on some other camera forums.

Any help will be greatly appreciated.
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Old Apr 13, 2010, 8:15 AM   #5
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Speaking for myself, I've got better things to do than comment on conspiracy theories. ;-)
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