Hi Sylvia
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You're right, but I disagree about the incidence of the flash over the lens
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Well I never said that. What I actually said was
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Red eye is caused because the flash is too close to the lens
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I did not go into too much detail (I was trying to keep it simple) but I will explain further.
There are two things which cause red eye
The angle.
Light travels from the flash to the subject. The light hits the back of the retina and is reflected out. If the camera is in the path of this reflected light then it will show as red eye on the image.
This is much more common when the flash is close to the lens because most subjects are looking at the camera and the angles are right to produce red eye.
Pupil size.
The dilation or contraction of the pupil also has a role to play. The larger the pupil then the more chance of this happening. This is why children and drunks are more prone to red eye.
Asking the subject to look at a bright light will help by contracting the pupils (compact cameras have a red eye reduction mode which gives a pre flash to do the same thing)
However women look far sexier if their pupils are dilated So it is better (for women) to Not contract the pupils and get them to look ‘off camera’ (and hence change the angle)
Camera manufacturers have always been aware that moving the flash away from the lens helped to reduce red eye. And in the past there have been novel methods to try to achieve this. The Kodak Advantix (aps) cameras had a lift up lens cover with the flash at the top.
The canon ixus z70 had a lever to slide the flash out and away from the lens etc. More recently as cameras get smaller this is getting impossible to do And all current cameras rely on a red eye reduction pre flash (SLRs do still have a pop up flash)
Lens flair is not a problem with compacts because the manufacturers design the camera so that the flash is behind the lens.
Red eye is now more of a common problem that it was years ago. In the 1950’s and 60’s cameras did not have a built in flash. It was necessary to buy a flash bracket and external flashun. Red eye was very rare because the flash was father away from the lens.
Ken