posted on Dec, 9 2012 @ 10:38 AM
reply to post by elevenaugust
ETA Thanks, nicely done! I guess I was putting this simplified version together when you posted that.
Might as well save these posts though I'm sure they will be needed again in a few months or so.
Understanding lens flare
Lens flare is created when non-image forming light enters the lens and subsequently hits the camera's film or digital sensor.
These take the form of polygonal bright regions (usually 5-8 sides), in addition to bright streaks and an overall reduction in contrast (see below).
The polygonal shapes vary in size and can actually become so large that they occupy a significant fraction of the image. Look for flare near very
bright objects, although its effects can also be seen far away from the actual source
All but the simplest cameras contain lenses which are actually comprised of several "lens elements." Lens flare is caused by non-image light which
does not pass (refract) directly along its intended path, but instead reflects internally on lens elements any number of times (back and forth) before
finally reaching the film or digital sensor.
Although flare is technically caused by internal reflections, this often requires very intense light sources in order to become significant (relative
to refracted light). Flare-inducing light sources may include the sun, artificial lighting and even a full moon.
Lens flares 'extend and retract' from the bright light source at different lengths due to which lens the flare is coming from: concave, flat or
convex, and how far they are from each other during zoom etc.
i.e. as one points the camera toward the light source, they begin to gather in the middle.
As one moves the camera away from the light source, they begin to move away, radiating away from the light source in opposite direction.
Back when I started shooting and developing photos back in the 80's this was a difficult phenomena to control because it was generally not visible
through the view finder. So shades or hoods were used to reduce the effects.
edit on 9-12-2012 by Lonewulph because: (no reason given)