p500vax:yin (01/14/83)
the problem you describe is called (logically enough) 'redeye'.
it is caused by light from the flash entering the pupil of the eye
and bouncing off the retina, returning to the camera lens.
since the pupil is fairly small, this is only a problem when the
flash is in almost a direct line with the camera lens. to avoid it
your flash needs to be offset from the usual position on the hotshoe
or you need a flash with a position adjustment. any way of offsetting
the light path from the direct line will work.
flash pictures of people taken by bouncing the light off a light-
colored ceiling or wall are usually better anyway. this is because
a direct flash is very harsh and eliminates any depth/structuring
caused by shadows. if you do bounce, be aware that you will lose
about 1-2 f-stops (totally nominal, dependent on actual reflectivity
of the surface being bounced off). this is a problem if your flash
does not have a light sensor that can be placed in the return path
of the light. if you aren't able to do this then you have to open
your aperture by the estimated number of stops lost to compensate.
- yin shih -
megatest, sunnyvaleimm (01/15/83)
#R:tekid:-72600:harpo:10900002:000:328 harpo!imm Jan 14 17:20:00 1983 If you can, get an extender to move the flash several inches above the camera.. It will kept a direct path from the eyes. Bouch flash will also work but you lose a lot of light. If you flash head tilts, rather than bouncing from the ceiling, tilt the flash and add a white card to the top of the flash to provide the bounce.
pmk (01/17/83)
What is happening is that the flash source is to close to the lens
and and you are getting a reflection of the blood vessels on the
retina. This happens especially with pocket instamatic cameras.
The cure is to move the flash further away from the lens.
Pat Kelliher
pyuxll!pmkwolit (01/17/83)
Well, MY guess is that your subjects (the ones with the red eyes) have herpes. As for what can be done about it, the answer is, alas, nothing.